WO2011108665A1

WO2011108665A1 - Radiation-sensitive resin composition and resist pattern formation method

Info

Publication number: WO2011108665A1
Application number: PCT/JP2011/054967
Authority: WO
Inventors: 峰規川上; 恭彦松田; 友洋柿澤
Original assignee: Jsr株式会社
Priority date: 2010-03-04
Filing date: 2011-03-03
Publication date: 2011-09-09
Also published as: JPWO2011108665A1; TW201144932A

Abstract

Provided are a radiation-sensitive resin composition, from which a chemically amplified resist showing reduced line width roughness and ensuring the formation of a desired pattern shape at a high accuracy can be obtained, and a method for forming a resist pattern using the same. The radiation-sensitive resin composition comprises a polymer [A] containing a repeating unit represented by general formula (1) and having an acid-dissociating group, a radiation-sensitive acid generator [B], and a fluorine-containing polymer [C], wherein the ratio of fluorine atoms contained in polymer [A] is smaller than the ratio of fluorine atoms contained in polymer [C]. In general formula (1), R¹ represents a hydrogen atom, a trifluoromethyl group or a C_1-4 alkyl group; R² represents a C_1-20 hydrocarbon group or a C_1-20 fluorohydrocarbon group; and Q¹ represents a divalent linking group.

Description

Radiation-sensitive resin composition and resist pattern forming method

The present invention relates to a radiation-sensitive resin composition that provides a chemically amplified resist capable of accurately forming a pattern having a desired shape while suppressing the occurrence of variations in line width, and a resist pattern forming method using the same.

In the field of microfabrication for manufacturing integrated circuit elements, lithography technology capable of microfabrication at a level of 0.10 μm or less is eagerly desired in order to obtain a higher degree of integration. However, in the conventional lithography technique, near ultraviolet rays such as i-line are used as exposure light, and it is extremely difficult to perform fine processing at a level of 0.10 μm or less (sub quarter micron level) with this near ultraviolet rays. Therefore, in order to enable microfabrication at a level of 0.10 μm or less, development of a lithography technique using radiation having a shorter wavelength is being performed. Examples of radiation having a shorter wavelength include an emission line spectrum of a mercury lamp, far ultraviolet rays such as an excimer laser, an X-ray, and an electron beam. Among these, KrF excimer laser (wavelength 248 nm) and ArF excimer laser (wavelength 193 nm) are attracting attention.

Along with the attention of excimer lasers, many materials for photoresist films for excimer lasers have been proposed. For example, it contains a component having an acid-dissociable functional group and a component that generates an acid upon irradiation with radiation (hereinafter referred to as “exposure”) (hereinafter referred to as “acid generator”), and these chemical amplification effects And the like (hereinafter referred to as “chemically amplified resist”). As a chemically amplified resist, specifically, a composition containing a resin having a tert-butyl ester group of carboxylic acid or a tert-butyl carbonate group of phenol and an acid generator has been reported. In this composition, the tert-butyl ester group or tert-butyl carbonate group present in the resin is dissociated by the action of an acid generated by exposure, and the resin has an acidic group composed of a carboxyl group or a phenolic hydroxyl group. To have. As a result, the exposed portion of the photoresist film becomes readily soluble in an alkali developer, so that a desired resist pattern can be formed.

However, in the field of microfabrication, it is desired to form a finer resist pattern (for example, a fine resist pattern having a line width of about 45 nm). In order to make it possible to form a finer resist pattern, for example, the light source wavelength of the exposure apparatus can be shortened, the numerical aperture (NA) of the lens can be increased, and the like. However, shortening the light source wavelength requires a new exposure apparatus, but such an apparatus is expensive. Further, when the numerical aperture of the lens is increased, the resolution and the depth of focus are in a trade-off relationship. Therefore, there is a problem that the depth of focus is lowered even if the resolution can be improved.

Therefore, in recent years, a liquid immersion lithography (liquid immersion lithography) method has been reported as a lithography technique for solving such problems. This method is a method in which a liquid for immersion exposure (for example, pure water, fluorine-based inert liquid, or the like) is interposed between the lens and the photoresist film (on the photoresist film) at the time of exposure. According to this method, the exposure optical path space that has been conventionally filled with an inert gas such as air or nitrogen is filled with an immersion exposure liquid having a refractive index (n) larger than that of air or the like. Even when the same exposure light source is used, the same effect as when the light source wavelength of the exposure apparatus is shortened, that is, high resolution can be obtained. Moreover, there is no reduction in the depth of focus.

Therefore, according to such an immersion exposure method, it is possible to form a resist pattern that is low in cost, excellent in resolution, and also excellent in depth of focus, using a lens mounted on an existing apparatus. it can. Therefore, a radiation-sensitive resin composition used in the immersion exposure method is disclosed in which a fluorine-based polymer is added (see, for example, Patent Documents 1 to 3).

International Publication No. 04/116664 JP 2007-304537 A JP 2007-249152 A

In the semiconductor field, a higher degree of integration is required. In addition to superior sensitivity and a wide exposure margin, a radiation-sensitive resin that can be formed with a small line width roughness (LWR: Line Width Roughness). Compositions are becoming necessary.

The present invention provides a radiation-sensitive resin composition that provides a chemically amplified resist capable of accurately forming a pattern having a desired shape while suppressing the occurrence of variations in line width, and a resist pattern forming method using the same. The purpose is to do.

The present invention is as follows.
1. [A] A polymer containing a repeating unit represented by the following general formula (1) and having an acid-dissociable group, [B] a radiation-sensitive acid generator, and [C] a polymer containing a fluorine atom And the content rate of the fluorine atom contained in the said polymer [A] is less than the content rate of the fluorine atom contained in the said polymer [C], The radiation sensitive resin composition characterized by the above-mentioned.

(Wherein R ¹ is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, and R ² is a hydrocarbon group having 1 to 20 carbon atoms or a fluorinated carbon atom having 1 to 20 carbon atoms) A hydrogen group, and Q ¹ is a divalent linking group.)
2. 2. The content of the repeating unit represented by the general formula (1) is 5 to 50 mol% when the total amount of the repeating units constituting the polymer [A] is 100 mol%. Radiation sensitive resin composition.
3. 3. The radiation sensitive resin composition according to 1 or 2 above, wherein the polymer [A] further contains a repeating unit represented by the following general formula (2).

(Wherein R ³ is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, and R ⁴ is independently a linear or branched alkyl group having 1 to 4 carbon atoms. Or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a divalent formed by bonding two R ⁴ to each other and having 4 to 20 carbon atoms. (It may be an alicyclic hydrocarbon group or a derivative group thereof.)
4). Any of 1 to 3 above, wherein the polymer [A] further contains at least one repeating unit selected from the group consisting of repeating units represented by the following general formulas (3-1) to (3-6): A radiation-sensitive resin composition according to claim 1.

(Wherein R ⁵ is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, R ⁶ is a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, R ⁷ is a single bond or a methylene group, R ⁸ is a hydrogen atom or a methoxy group, R ⁹ is an oxygen atom or a methylene group, p is 1, 2 or 3, and m is 0 or 1)
5. Any one of the above 1 to 4 wherein the polymer [C] contains at least one repeating unit selected from the group consisting of repeating units represented by the following general formulas (c1-1) to (c1-3) The radiation sensitive resin composition as described.

(Wherein R ²¹ represents a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, R ²² represents a fluorinated hydrocarbon group having 1 to 30 carbon atoms, and R ²³ represents Independently a hydrogen atom, a fluorine atom or a fluorinated hydrocarbon group having 1 to 30 carbon atoms, R ²⁴ is a hydrogen atom, an acid dissociable group or an alkali dissociable group, and Q ³ is (g + 1) Q ⁴ is a divalent linking group and g is 1, 2 or 3. provided that in formulas (c1-2) and (c1-3), all R ²³ Is not a hydrogen atom.)
6). [A] For immersion exposure, comprising a polymer having a repeating unit represented by the following general formula (1) and having an acid-dissociable group, and [B] a radiation-sensitive acid generator Radiation sensitive resin composition.

(Wherein R ¹ is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, and R ² is a hydrocarbon group having 1 to 20 carbon atoms or a fluorinated carbon atom having 1 to 20 carbon atoms) A hydrogen group, and Q ¹ is a divalent linking group.)
7). Using the radiation-sensitive resin composition according to any one of 1 to 6 above, a step of forming a photoresist film on a substrate;
Placing a liquid for immersion exposure on the photoresist film, and subjecting the photoresist film to immersion exposure via the liquid for immersion exposure;
Developing the photoresist film exposed to immersion and forming a resist pattern; and
A resist pattern forming method comprising:

According to the radiation-sensitive resin composition and the radiation-sensitive resin composition for immersion exposure of the present invention, it is possible to provide a chemically amplified resist capable of maintaining a good LWR while maintaining a wide exposure margin. it can.
Further, according to the pattern forming method of the present invention, the chemically amplified resist to be used is excellent in developability, and it is possible to accurately form a pattern having a desired shape while suppressing the occurrence of variations in line width.

Hereinafter, the present invention will be described in detail. In the following description, “(meth) acryl” means acryl and methacryl.

1. Radiation-sensitive resin composition The radiation-sensitive resin composition of the present invention includes [A] a repeating unit represented by the following general formula (1) (hereinafter referred to as “repeating unit (I-1)”). A polymer having an acid dissociable group (hereinafter referred to as “polymer [A]”), [B] a radiation-sensitive acid generator (hereinafter referred to as “acid generator [B]”), and [C ] A polymer containing a fluorine atom (hereinafter referred to as “polymer [C]”), and the content of fluorine atom contained in the polymer [A] is the same as that of the fluorine atom contained in the polymer [C]. Less than the content rate. The fluorine atom content in the polymers [A] and [C] can be measured by ¹³ C-NMR.
Here, the “acid-dissociable group” is a group in which an alkali-soluble site is protected with a protecting group, and means a group that is not “alkali-soluble” until the protecting group is removed with an acid. .

(Wherein R ¹ is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, and R ² is a hydrocarbon group having 1 to 20 carbon atoms or a fluorinated carbon atom having 1 to 20 carbon atoms) A hydrogen group, and Q ¹ is a divalent linking group.)

Further, another radiation-sensitive resin composition for immersion exposure according to the present invention is a composition containing the polymer [A] and the acid generator [B].

1-1. Polymer [A]
This polymer [A] is a polymer containing the repeating unit (I-1) represented by the above general formula (1) and having an acid dissociable group, and preferably becomes alkali-soluble by the action of an acid. It is an alkali-insoluble or hardly alkali-soluble polymer. Here, “alkali insoluble or hardly soluble in alkali” means that the photoresist film under the alkali development conditions employed when forming a resist pattern from a photoresist film formed using the composition of the present invention. When a film having a thickness of 100 nm formed using only the polymer [A] instead of is developed, it means that 50% or more of the initial film thickness of this film remains after development.
The acid dissociable group contained in the polymer [A] may be contained in the repeating unit (I-1), and may be contained in other repeating units contained in the polymer, if necessary. In the present invention, the polymer [A] is preferably a copolymer further containing other repeating units as described later.

1-1-1. Repeating unit (I-1)
In the general formula (1), R ¹ is a hydrogen atom, a trifluoromethyl group, or an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, tert-butyl group and the like. . R ¹ is preferably a hydrogen atom or a methyl group.

In the general formula (1), R ² is a hydrocarbon group having 1 to 20 carbon atoms or a fluorinated hydrocarbon group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, a carbon number of 1 -20 fluorinated alkyl group, cycloalkyl group having 3-20 carbon atoms, fluorinated cycloalkyl group having 3-20 carbon atoms, and the like.
Specific examples of the alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n- Examples include hexyl group, n-heptyl group, octyl group and the like.
Specific examples of the fluorinated alkyl group having 1 to 20 carbon atoms include a difluoromethyl group, a perfluoromethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a perfluoroethyl group, 2 , 2,3,3-tetrafluoropropyl group, perfluoroethylmethyl group, perfluoropropyl group, 2,2,3,3,4,4-hexafluorobutyl group, perfluorobutyl group, 1,1-dimethyl -2,2,3,3-tetrafluoropropyl group, 1,1-dimethyl-2,2,3,3,3-pentafluoropropyl group, 2- (perfluoropropyl) ethyl group, 2,2,3 , 3,4,4,5,5-octafluoropentyl group, perfluoropentyl group, 1,1-dimethyl-2,2,3,3,4,4-hexafluorobutyl group, 2- (perfluoro (Robutyl) ethyl group, 2,2,3,3,4,4,5,5,6,6-decafluorohexyl group, perfluoropentylmethyl group, perfluorohexyl group, 1,1-dimethyl-2,2 , 3,3,4,4,5,5-octafluoropentyl group, 1,1-dimethyl-2,2,3,3,4,4,5,5,5-nonafluoropentyl group, 2- ( Perfluoropentyl) ethyl group, 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl group, perfluorohexylmethyl group, perfluoroheptyl group, 2- ( Perfluorohexyl) ethyl group, 2,2,3,3,4,4,5,5,6,6,7,7,8,8-tetradecafluorooctyl group, perfluoroheptylmethyl group, perfluorooctyl Group, 2- (perfluoroheptyl) Til group, 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluorononyl group, perfluorooctylmethyl group, perfluorononyl Group, 2- (perfluorooctyl) ethyl group, 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10-octadeca Fluorodecyl group, perfluorononylmethyl group, perfluorodecyl group, 2,2,3,4,4,4-hexafluorobutyl group, 2,2,3,3,4,4,4-heptafluorobutyl group 3,3,4,4,5,5,6,6,6-nonafluorohexyl group, 3,3,4,4,5,5,6,6,7,7,8,8,8- Examples include a tridecafluorooctyl group. Of these, a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, and a perfluorooctyl group are preferable.
Specific examples of the cycloalkyl group having 3 to 20 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and the like.
As a specific example of a fluorinated cycloalkyl group having 3 to 20 carbon atoms, at least one hydrogen atom of the cycloalkyl group may be substituted with a fluorine atom.

In the general formula (1), Q ¹ is a divalent linking group, preferably a divalent hydrocarbon group. The divalent hydrocarbon group is preferably a chain hydrocarbon group or a cyclic hydrocarbon group, and specific examples thereof include methylene group, ethylene group, 1,3-propylene group and 1,2-propylene group. Propylene group, tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, Pentadecamethylene group, hexadecamethylene group, heptacamethylene group, octadecamethylene group, nonadecamethylene group, insalen group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl-1,4-butyl group Saturated chain hydrocarbon groups such as a len group, a methylidene group, an ethylidene group, a propylidene group and a 2-propylidene group; a cyclobutylene group such as a 1,3-cyclobutylene group and a cyclopentylene such as a 1,3-cyclopentylene group Monocyclic such as cycloalkylene group having 3 to 10 carbon atoms such as ylene group, cyclohexylene group such as 1,4-cyclohexylene group, cyclooctylene group such as 1,5-cyclooctylene group, etc. Hydrocarbon ring group; 4 carbon atoms such as norbornylene group such as 1,4-norbornylene group, 2,5-norbornylene group, adamantylene group such as 1,5-adamantylene group, 2,6-adamantylene group, etc. And a crosslinked cyclic hydrocarbon group such as a bicyclic to tetracyclic hydrocarbon group which is 30.

When Q ¹ contains a divalent aliphatic cyclic hydrocarbon group, it has an alkylene group having 1 to 4 carbon atoms as a spacer between the —NH— group and the aliphatic cyclic hydrocarbon group. Is preferred. That is, Q ¹ can be a divalent hydrocarbon group in which an aliphatic cyclic hydrocarbon group and an alkylene group having 1 to 4 carbon atoms are linked.

Q ¹ in the general formula (1) is preferably a 2,5-norbornylene group, a hydrocarbon group containing a 2,6-norbornylene group, an ethylene group, or a 1,2-propylene group.

The polymer [A] may contain only one type of repeating unit (I-1), or may contain two or more types.

Examples of the monomer that gives the repeating unit (I-1) represented by the general formula (1) include compounds represented by the following formulas (1-1) and (1-2).

The content of the repeating unit (I-1) constituting the polymer [A] is preferably 5 to 50 mol% with respect to 100 mol% in total of all the repeating units constituting the polymer [A]. More preferably, it is 5 to 30 mol%. If the content of the repeating unit (I-1) is too small, the LWR improving effect may not be observed. On the other hand, if the content of the repeating unit (I-1) is too large, the contrast after development is impaired, and a good pattern shape may not be obtained.

1-1-2. Other Repeating Units The polymer [A] contains, in addition to the repeating unit (I-1), a repeating unit having an acid dissociable group represented by the following general formula (2) (hereinafter referred to as “repeating unit (I)”. -2) ") and repeating units having a lactone skeleton represented by the following general formulas (3-1) to (3-6) (hereinafter also referred to as" repeating units (I-3) "). ) May be included.

(Wherein R ³ is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, and R ⁴ is independently a linear or branched alkyl group having 1 to 4 carbon atoms. Or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a divalent formed by bonding two R ⁴ to each other and having 4 to 20 carbon atoms. (It may be an alicyclic hydrocarbon group or a derivative group thereof.)

(Wherein R ⁵ is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, R ⁶ is a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, R ⁷ is a single bond or a methylene group, R ⁸ is a hydrogen atom or a methoxy group, R ⁹ is an oxygen atom or a methylene group, p is 1, 2 or 3, and m is 0 or 1)

1-1-2-1. Repeating unit (I-2)
This repeating unit (I-2) is a unit having an acid dissociable group.
In the above general formula (2), R ³ is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, tert-butyl group and the like. . R ³ is preferably a hydrogen atom or a methyl group.

In the above general formula (2), R ^{4 s} are independently of each other a linear or branched alkyl group having 1 to 4 carbon atoms, or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms. It is.

Examples of linear and branched alkyl groups having 1 to 4 carbon atoms represented by R ⁴ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a 2-methylpropyl group, 1 -Methylpropyl group, tert-butyl group and the like.
Examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms represented by R ⁴ include a cyclopentyl group, a cyclopentylmethyl group, a 1- (1-cyclopentylethyl) group, and 1- (2-cyclopentylethyl). ) Group, cyclohexyl group, cyclohexylmethyl group, 1- (1-cyclohexylethyl) group, 1- (2-cyclohexylethyl group), cycloheptyl group, cycloheptylmethyl group, 1- (1-cycloheptylethyl) group, 1- (2-cycloheptylethyl) group, 2-norbornyl group, bicyclo [2.2.1] heptyl group, bicyclo [2.2.1] octyl group, tricyclo [5.2.1.0 ^2,6 ] Decanyl group, tricyclo [3.3.1.1 ^3,7 ] decanyl group, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecanyl group, alicyclic alkyl group such as adamantyl group, and the like. Of these, a cyclopentyl group, a cyclohexyl group, a bicyclo [2.2.1] heptyl group and an adamantyl group are preferred.

Further, in the repeating unit represented by the above general formula (2), a divalent alicyclic carbon atom having 4 to 20 carbon atoms formed by bonding any two of the three R ^{4 s} to each other. It may have a hydrogen group and a derivative group thereof. Examples thereof include a bridged skeleton such as an adamantane skeleton, a norbornane skeleton, a tricyclodecane skeleton, and a tetracyclododecane skeleton, cyclobutane, cyclopentane, cyclohexane, and cycloheptane. Groups having a cycloalkane skeleton such as cyclooctane; the hydrogen atoms contained in these groups are methyl, ethyl, n-propyl, isopropyl, n-butyl, 2-methylpropyl, 1-methyl Groups substituted with one or more linear, branched or cyclic alkyl groups having 1 to 10 carbon atoms such as propyl group and tert-butyl group And a group having an alicyclic skeleton such as.

Preferable examples of the ester bond portion —C (R ⁴ ) ₃ in the general formula (2) include tert-butyl group, 1-n- (1-ethyl-1-methyl) propyl group, 1-n- (1 , 1-dimethyl) propyl group, 1-n- (1,1-dimethyl) butyl group, 1-n- (1,1-dimethyl) pentyl group, 1- (1,1-diethyl) propyl group, 1- n- (1,1-diethyl) butyl group, 1-n- (1,1-diethyl) pentyl group, 1- (1-methyl) cyclopentyl group, 1- (1-ethyl) cyclopentyl group, 1- (1 -N-propyl) cyclopentyl group, 1- (1-isopropyl) cyclopentyl group, 1- (1-methyl) cyclohexyl group, 1- (1-ethyl) cyclohexyl group, 1- (1-n-propyl) cyclohexyl group, 1- (1-Isopropyl Cyclohexyl, 1- {1-methyl-1- (2-norbornyl)} ethyl, 1- {1-methyl-1- (2-tetracyclodecanyl)} ethyl, 1- {1-methyl-1 -(1-adamantyl)} ethyl group, 2- (2-methyl) norbornyl group, 2- (2-ethyl) norbornyl group, 2- (2-n-propyl) norbornyl group, 2- (2-isopropyl) norbornyl Group, 2- (2-methyl) tetracyclodecanyl group, 2- (2-ethyl) tetracyclodecanyl group, 2- (2-n-propyl) tetracyclodecanyl group, 2- (2-isopropyl) Tetracyclodecanyl group, 1- (1-methyl) adamantyl group, 1- (1-ethyl) adamantyl group, 1- (1-n-propyl) adamantyl group, 1- (1-isopropyl) adamantyl group, etc. of For example, a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, tert-butyl group, etc. And a group substituted with one or more of 4 linear, branched or cyclic alkyl groups.

The polymer [A] may contain only one type of repeating unit (I-2), or may contain two or more types.

Examples of the monomer that gives the repeating unit (I-2) include (meth) acrylic acid 2-methyladamantyl-2-yl ester, (meth) acrylic acid 2-methyl-3-hydroxyadamantyl-2-yl ester, (Meth) acrylic acid 2-ethyladamantyl-2-yl ester, (meth) acrylic acid 2-ethyl-3-hydroxyadamantyl-2-yl ester, (meth) acrylic acid 2-n-propyladamantyl-2-yl ester (Meth) acrylic acid 2-isopropyladamantyl-2-yl ester, (meth) acrylic acid-2-methylbicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid-2-ethylbicyclo ester [2.2.1] Hept-2-yl ester, (meth) acrylic acid-8-methyltricyclo [5.2.1.0] , 6] decan-8-yl ester, (meth) ethyl-8-acrylic acid tricyclo [5.2.1.0 ^2,6] decan-8-yl ester, (meth) methyl-4-acrylic acid tetra Cyclo [6.2.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl ester, (meth) acrylic acid-4-ethyltetracyclo [6.2.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl ester, (meth) acrylic acid 1- (bicyclo [2.2.1] hept-2-yl) -1-methylethyl ester, (meth) acrylic acid 1- (tricyclo [5.2.1.0 ^2,6 ] decan-8-yl) -1-methylethyl ester, (meth) acrylic acid 1- (tetracyclo [6.2.1 ^3,6 0.0 ^2,7 ] dodecane -4-yl) -1-methylethyl ester, (meth) acrylic acid 1- (adamantan-1-yl) -1-methylethyl ester, (meth) acrylic acid 1- (3-hydroxyadamantan-1-yl) -1-methyl ethyl ester, (meth) acrylic acid 1,1-dicyclohexylethyl ester, (meth) acrylic acid 1,1-di (bicyclo [2.2.1] hept-2-yl) ethyl ester, Meth) acrylic acid 1,1-di (tricyclo [5.2.1.0 ^2,6] decan-8-yl) ethyl ester, (meth) acrylic acid 1,1-di (tetracyclo [6.2.1 ^3,6 .0 ^2,7 ] dodecan-4-yl) ethyl ester, (meth) acrylic acid 1,1-di (adamantan-1-yl) ethyl ester, (meth) acrylic acid 1-methyl-1-cyclopentyl Examples include esters, (meth) acrylic acid 1-ethyl-1-cyclopentyl ester, (meth) acrylic acid 1-methyl-1-cyclohexyl ester, (meth) acrylic acid 1-ethyl-1-cyclohexyl ester, and the like.

Among the above monomers, (meth) acrylic acid 2-methyladamantyl-2-yl ester, (meth) acrylic acid 2-ethyladamantyl-2-yl ester, (meth) acrylic acid-2-methylbicyclo [2. 2.1] hept-2-yl ester, (meth) acrylic acid-2-ethylbicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid 1- (bicyclo [2.2.1] ] Hept-2-yl) -1-methylethyl ester, (meth) acrylic acid 1- (adamantan-1-yl) -1-methylethyl ester, (meth) acrylic acid 1-methyl-1-cyclopentyl ester, ( (Meth) acrylic acid 1-ethyl-1-cyclopentyl ester, (meth) acrylic acid 1-methyl-1-cyclohexyl ester and (meth) acrylic acid 1-ethyl 1-cyclohexyl ester is particularly preferred.

When the polymer [A] contains the repeating unit (I-2), the content of the repeating unit (I-2) is 100 mol% in total of all the repeating units constituting the polymer [A]. On the other hand, it is preferably 15 to 85 mol%, more preferably 25 to 75 mol%, still more preferably 30 to 60 mol%. If the content of the repeating unit (I-2) is too small, the contrast after development is impaired, and a good pattern shape may not be obtained. On the other hand, when the content of the repeating unit (I-2) is too large, the adhesion with the base substrate becomes insufficient, and the pattern film may be peeled off.

1-1-2-2. Repeating unit (I-3)
This repeating unit (I-3) is a unit having a lactone skeleton. When the polymer [A] contains this repeating unit (I-3), the adhesion of the resist pattern to the substrate can be improved.

In the above general formulas (3-1) to (3-6), R ⁵ is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, tert-butyl group and the like. . R ⁵ is preferably a hydrogen atom or a methyl group.

In the general formula (3-1), R ⁶ represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms.
Examples of the alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, tert-butyl group and the like. .
In the alkyl group having 1 to 4 carbon atoms having a substituent, a hydrogen atom contained in the alkyl group is substituted with at least one of a hydroxyl group, a cyano group, a carboxyl group, a halogen atom, and the like. Can be.

The polymer [A] may contain only one type of repeating unit (I-3), or may contain two or more types.

Examples of the monomer giving the repeating unit (I-3) include compounds represented by the following general formulas (3-1m) to (3-6m).
The following general formula (3-1m) is a monomer that gives the repeating unit represented by the above general formula (3-1), and is represented by the following general formulas (3-2m) to (3-6m). Similarly, these compounds are monomers that give the repeating units represented by the general formulas (3-2) to (3-6), respectively.

Examples of the monomer giving the repeating unit (I-3) include (meth) acrylic acid-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] non-2-yl ester, (Meth) acrylic acid-9-methoxycarbonyl-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] non-2-yl ester, (meth) acrylic acid-5-oxo-4 -Oxa-tricyclo [5.2.1.0 ^3,8 ] dec-2-yl ester, (meth) acrylic acid-10-methoxycarbonyl-5-oxo-4-oxa-tricyclo [5.2.1. 0 ^3,8 ] Nona-2-yl ester, (meth) acrylic acid-6-oxo-7-oxa-bicyclo [3.2.1] oct-2-yl ester, (meth) acrylic acid-4-methoxy Carbonyl-6-oxo-7- Xa-bicyclo [3.2.1] oct-2-yl ester, (meth) acrylic acid-7-oxo-8-oxa-bicyclo [3.3.1] oct-2-yl ester, (meth) acrylic Acid-4-methoxycarbonyl-7-oxo-8-oxa-bicyclo [3.3.1] oct-2-yl ester, (meth) acrylic acid-2-oxotetrahydropyran-4-yl ester, (meth) Acrylic acid-4-methyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-4-ethyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-4-propyl-2 -Oxotetrahydropyran-4-yl ester, (meth) acrylic acid-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-2,2 -Dimethyl-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-4,4-dimethyl-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-2-oxotetrahydrofuran-3-yl ester (Meth) acrylic acid-4,4-dimethyl-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-5,5-dimethyl-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid -2-Oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-5-oxotetrahydrofuran-2-ylmethyl ester, (meth) acrylic acid-3,3-dimethyl-5-oxotetrahydrofuran-2-ylmethyl ester , (Meth) acrylic acid-4,4-dimethyl-5-oxy Tetrahydrofuran-2-yl methyl ester.

When the polymer [A] contains the repeating unit (I-3), the content of the repeating unit (I-3) is 100 mol% in total of all the repeating units constituting the polymer [A]. On the other hand, it is preferably 5 to 80 mol%, more preferably 10 to 70 mol%, and still more preferably 10 to 60 mol%. If the content of the repeating unit (I-3) is too small, the adhesion to the substrate may be insufficient and the pattern may be peeled off. On the other hand, if the amount is excessive, the solubility in an alkali developer may be insufficient and development defects may increase.

The polymer [A] includes, as other repeating units, in addition to the repeating units (I-2) and (I-3), a repeating unit having an alicyclic structure other than those described above (hereinafter referred to as “repeating unit ( I-4) ”), and a repeating unit derived from an aromatic unsaturated compound (hereinafter also referred to as“ repeating unit (I-5) ”).

1-1-2-3. Repeating unit (I-4)
This repeating unit (I-4) is another repeating unit having an alicyclic structure excluding the above repeating units (I-2) and (I-3). When the polymer [A] contains the repeating unit (I-4), etching resistance can be improved.
Examples of the repeating unit (I-4) include repeating units represented by the following general formula (4).

(Wherein R ¹¹ is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, and R ¹² is a monovalent group containing an alicyclic hydrocarbon group having 4 to 20 carbon atoms. is there.)

In the general formula (4), the alkyl group having 1 to 4 carbon atoms represented by R ¹¹ includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a 2-methylpropyl group, Examples thereof include a 1-methylpropyl group and a tert-butyl group. R ¹¹ is preferably a hydrogen atom or a methyl group.

R ¹² is a monovalent group containing an alicyclic hydrocarbon group having 4 to 20 carbon atoms, and may be a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms. It may be a derivative group of a hydrocarbon group. Examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms include a cyclopentyl group, a cyclopentylmethyl group, a 1- (1-cyclopentylethyl) group, a 1- (2-cyclopentylethyl) group, a cyclohexyl group, and a cyclohexylmethyl group. Group, 1- (1-cyclohexylethyl) group, 1- (2-cyclohexylethyl group), cycloheptyl group, cycloheptylmethyl group, 1- (1-cycloheptylethyl) group, 1- (2-cycloheptylethyl) ) Group, 2-norbornyl group, bicyclo [2.2.1] heptyl group, bicyclo [2.2.1] octyl group, tricyclo [5.2.1.0 ^2,6 ] decanyl group, tricyclo [3. 3.1.1 ^3,7 ] decanyl group, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecanyl group, alicyclic alkyl group such as adamantyl group, and the like.

When R ¹² is a derivative group of the above alicyclic hydrocarbon group, R ¹² represents a hydrogen atom contained in the alicyclic hydrocarbon group as a methyl group, an ethyl group, an n-propyl group, an isopropyl group. A linear, branched or cyclic alkyl group having 1 to 4 carbon atoms such as n-butyl group, 2-methylpropyl group, 1-methylpropyl group, tert-butyl group, hydroxyl group, cyano group, carbon A hydroxyalkyl group, a carboxyl group, a group substituted with one or more oxygen atoms or one or more of oxygen atoms can be used.

The polymer [A] may contain only one type of repeating unit (I-4), or may contain two or more types.

Examples of the monomer that gives the repeating unit (I-4) include (meth) acrylic acid-bicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid-bicyclo [2.2.2]. ] Oct-2-yl ester, (meth) acrylic acid-tricyclo [5.2.1.0 ^2,6 ] dec-7-yl ester, (meth) acrylic acid-tetracyclo [6.2.1.1 ^{3 , 6} . 0 ^2,7 ] dodec-9-yl ester, (meth) acrylic acid-tricyclo [3.3.1.1 ^3,7 ] dec-1-yl ester, (meth) acrylic acid-tricyclo [3.3. ^1.1,7 ] dec-2-yl ester and the like.

When the polymer [A] contains the repeating unit (I-4), the upper limit of the content of the repeating unit (I-4) is 100 mol in total of all the repeating units constituting the polymer [A]. % Is preferably 70 mol%, more preferably 60 mol%. If the content of the repeating unit (I-4) is too large, resolution may be lowered and a good pattern shape may not be obtained.

1-1-2-4. Repeating unit (I-5)
This repeating unit (I-5) is a repeating unit derived from an aromatic unsaturated compound.

In the above repeating unit (I-5), the aromatic structure part is preferably contained in the side chain of the polymer.
The polymer [A] may contain only one type of repeating unit (I-5), or may contain two or more types.

Examples of the aromatic unsaturated compounds include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-methoxystyrene, 3-methoxystyrene, 4-methoxystyrene, 4- (2-tert-butoxycarbonylethyloxy) styrene, 2-hydroxystyrene, 3-hydroxystyrene, 4-hydroxystyrene, 2-hydroxy-α-methylstyrene, 3-hydroxy-α-methylstyrene, 4-hydroxy-α -Methylstyrene, 2-methyl-3-hydroxystyrene, 4-methyl-3-hydroxystyrene, 5-methyl-3-hydroxystyrene, 2-methyl-4-hydroxystyrene, 3-methyl-4-hydroxystyrene, 3 , 4-Dihydroxystyrene, 2,4,6-trihydro Styrene, 4-tert-butoxystyrene, 4-tert-butoxy-α-methylstyrene, 4- (2-ethyl-2-propoxy) styrene, 4- (2-ethyl-2-propoxy) -α-methylstyrene, 4- (1-ethoxyethoxy) styrene, 4- (1-ethoxyethoxy) -α-methylstyrene, phenyl (meth) acrylate, benzyl (meth) acrylate, acenaphthylene, 5-hydroxyacenaphthylene, 1-vinyl Naphthalene, 2-vinylnaphthalene, 2-hydroxy-6-vinylnaphthalene, 1-naphthyl (meth) acrylate, 2-naphthyl (meth) acrylate, 1-naphthylmethyl (meth) acrylate, 1-anthryl (meth) acrylate, 2 -Anthryl (meth) acrylate, 9-anthryl (meth) acryl Rate, 9-anthrylmethyl (meth) acrylate, 1-vinylpyrene and the like.

When the polymer [A] contains the repeating unit (I-5), the upper limit of the content of the repeating unit (I-5) is 100 mol in total of all the repeating units constituting the polymer [A]. % Is preferably 40 mol%, more preferably 30 mol%. If the content of the repeating unit (I-5) is too large, the exposure light transmittance may be reduced during exposure, and a good pattern profile may not be obtained.

1-1-2-5. Preferred combinations of repeating units The combinations of repeating units constituting the polymer [A] and their contents are shown below.
(T1) It consists of the repeating unit (I-1), the repeating unit (I-2) and the repeating unit (I-3), and the content of all of these repeating units constituting the polymer [A] Preferably, 5 to 50 mol%, 15 to 85 mol% and 5 to 80 mol%, more preferably 5 to 30 mol%, 30 to 70 mol% and 10 to 70 mol%, respectively, with respect to the total of 100 mol% Is a polymer.
(T2) The repeating unit (I-1), the repeating unit (I-2), the repeating unit (I-3) and the repeating unit (I-4) are contained in the polymer [A]. Are preferably 5 to 50 mol%, 15 to 85 mol%, 5 to 80 mol%, and 5 to 80 mol%, more preferably 5 to 30 mol, respectively, with respect to a total of 100 mol% of all repeating units constituting Polymers that are mol%, 30-70 mol%, 10-50 mol%, and 5-50 mol%.

1-1-3. Content of Fluorine Atom In the radiation sensitive resin composition of the present invention, the content of the fluorine atom contained in the polymer [A] is less than the content of the fluorine atom contained in the polymer [C]. It is a feature. Thereby, the (C) polymer is likely to be unevenly distributed on the surface layer of the photoresist film. Accordingly, the water repellency of the surface layer portion of the photoresist film to be formed can be increased, and when applying immersion exposure, good water repellency can be obtained without separately forming an upper film (immersion upper film) on the surface. A photoresist film can be formed.
The fluorine atom content in the polymer [A] is smaller than that of the polymer [C] described later. The content of fluorine atoms is usually less than 10% by mass, preferably 0.1 to 9% by mass, more preferably 1 to 6% by mass, when the total amount of the polymer [A] is 100% by mass. is there. When the fluorine atom content in the polymer [A] is smaller than that of the polymer [C], the polymer [C] is likely to be unevenly distributed on the surface layer of the photoresist film. Therefore, when immersion exposure is applied, it is not necessary to separately form an immersion upper layer film, so that the immersion exposure can be carried out smoothly, the occurrence of variations in line width is suppressed, and a pattern with a desired shape is accurately obtained. A chemically amplified resist that can be well formed can be obtained.

1-1-4. Average Molecular Weight The weight average molecular weight (hereinafter referred to as “Mw”) of the polymer [A] is preferably 1,000 to 100,000, more preferably 1 in terms of polystyrene by gel permeation chromatography (GPC). 3,000 to 30,000, more preferably 1,000 to 20,000. If the Mw is less than 1,000, a photoresist film having excellent heat resistance may not be obtained. On the other hand, if Mw exceeds 100,000, the developability of the photoresist film may deteriorate.
The ratio (Mw / Mn) obtained by using GPC in terms of polystyrene-equivalent number average molecular weight (hereinafter referred to as “Mn”) and Mw is preferably 1 to 5, more preferably 1 to 3. is there.

1-1-5. Production Method The polymer [A] is a monomer that forms the repeating unit (I-1) in the presence of a radical polymerization initiator such as hydroperoxide, dialkyl peroxide, diacyl peroxide, and azo compound. It can manufacture by polymerizing the monomer raw material containing this in a suitable solvent.
The polymerization temperature is usually 40 ° C. to 150 ° C., preferably 50 ° C. to 120 ° C. The polymerization time is usually 1 to 48 hours, preferably 1 to 24 hours.

Examples of the solvent include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane and n-decane; cycloalkanes such as cyclohexane, cycloheptane and cyclooctane; decalin, norbornane and the like Alicyclic hydrocarbons; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene; halogenated hydrocarbons such as chlorobutane, bromohexane, dichloroethane, hexamethylene dibromide, chlorobenzene; ethyl acetate, acetic acid saturated carboxylic acid esters such as n-butyl, isobutyl acetate and methyl propionate; ketones such as acetone, 2-butanone, 4-methyl-2-pentanone and 2-heptanone; tetrahydrofuran, dimethoxyethane, diethoxyethane and the like Ethers; methanol, Ethanol, 1-propanol, 2-propanol, alcohols such as 4-methyl-2-pentanol. These solvents may be used alone or in combination of two or more.

In addition, in polymer [A] used for manufacture of the radiation sensitive resin composition of this invention or the radiation sensitive resin composition for immersion exposure, it is so preferable that there is little content of impurities, such as a halogen and a metal. When the content of such impurities is small, the sensitivity, resolution, process stability, pattern shape and the like of the photoresist film can be further improved. Therefore, it is preferable to subject the crude product containing the polymer [A] synthesized by the above method to purification. Examples of the purification method include chemical purification methods such as washing with water and liquid-liquid extraction, and methods combining these chemical purification methods with physical purification methods such as ultrafiltration and centrifugation.

Moreover, in the said polymer [A], it is so preferable that there is little content of the low molecular weight component originating in a monomer raw material. Specifically, the content is preferably 0.1% by mass or less, more preferably 0.07% by mass or less, and still more preferably 0.05% by mass or less with respect to the polymer [A]. When this content is 0.1% by mass or less, it is possible to suppress the amount of the eluate in the immersion exposure liquid such as water that is in contact with the immersion exposure. Furthermore, when the radiation-sensitive resin composition of the present invention or the radiation-sensitive resin composition for immersion exposure is stored, no foreign matter is generated, and the radiation-sensitive resin composition of the present invention or radiation exposure for immersion exposure is performed. Even when the conductive resin composition is applied, uneven application can be suppressed, and the occurrence of defects when forming the resist pattern can be sufficiently suppressed.
In addition, the low molecular weight component derived from the said monomer raw material means a monomer, a dimer, a trimer, an oligomer, etc., and can be normally made into a component with a molecular weight of 500 or less. Such components having a molecular weight of 500 or less are removed by, for example, chemical purification methods such as washing with water and liquid-liquid extraction, or a combination of these chemical purification methods and physical purification methods such as ultrafiltration and centrifugation. can do. The low molecular weight component derived from the monomer raw material can be analyzed by subjecting the crude product containing the polymer [A] to high performance liquid chromatography (HPLC).

1-2. Acid generator [B]
This acid generator [B] is used when the photoresist film formed by the radiation-sensitive resin composition of the present invention or the radiation-sensitive resin composition for immersion exposure is exposed through the immersion exposure liquid. , A component that generates an acid derived from the acid generator [B] from the exposed portion. By the action of the acid, the acid dissociable group contained in the polymer [A] is dissociated from the polymer in the exposed portion. The polymer from which the acid dissociable group is dissociated becomes readily soluble in an alkali developer. Then, a positive resist pattern having a desired shape can be obtained by removing an unnecessary portion of the photoresist film using an alkali developer.

As the acid generator [B] contained in the radiation-sensitive resin composition of the present invention or the radiation-sensitive resin composition for immersion exposure, conventionally known radiation-sensitive acid generators can be applied. For example, compounds described in paragraphs [0080] to [0113] of JP-A-2009-134088 can be used.

Examples of the acid generator [B] include triphenylsulfonium salt compounds, 4-cyclohexylphenyldiphenylsulfonium salt compounds, 4-tert-butylphenyldiphenylsulfonium salt compounds, tri (4-tert-butylphenyl) sulfonium salt compounds, diphenyl Iodonium salt compound, bis (4-tert-butylphenyl) iodonium salt compound, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium salt compound, 1- (3,5-dimethyl-4-hydroxy Phenyl) tetrahydrothiophenium salt compounds, succinimide compounds, bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide compounds, and the like. These acid generators may be used alone or in combination of two or more.

Examples of the triphenylsulfonium salt compound include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2-bicyclo [2.2.1]. ] Hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium = tricyclo [3.3.1.1 ^3,7 ] decanyl difluoromethanesulfonate, triphenylsulfonium 2- ( 3- tetracyclo ^[4.4.0.1 2,5 ^{.1 7,10]} dodecanyl) -1,1-difluoroethanesulfonate, triphenylsulfonium N, N'-bis (nonafluoro -n- butanesulfonyl) imidate And triphenylsulfonium camphorsulfonate.

Examples of the 4-cyclohexylphenyldiphenylsulfonium salt compound include 4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2- (3-tetracyclo [4. 4.0.1 ^2,5 .1 ^7,10 ] dodecanyl) -1,1-difluoroethanesulfonate, 4-cyclohexylphenyldiphenylsulfate Examples include onium N, N′-bis (nonafluoro-n-butanesulfonyl) imidate, 4-cyclohexylphenyldiphenylsulfonium camphorsulfonate, and the like.

Examples of the 4-tert-butylphenyldiphenylsulfonium salt compound include 4-tert-butylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-tert-butylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-tert-butylphenyldiphenylsulfonium. And perfluoro-n-octane sulfonate.
Examples of the tri (4-tert-butylphenyl) sulfonium salt compound include tri (4-tert-butylphenyl) sulfonium trifluoromethanesulfonate, tri (4-tert-butylphenyl) sulfonium nonafluoro-n-butanesulfonate, and the like. It is done.

Examples of the 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium salt compound include 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4 -N-butoxynaphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (4- n-Butoxynaphthalen-1-yl) tetrahydrothiophenium 2- (3-tetracycline ^[4.4.0.1 2,5 ^{.1 7,10]} dodecanyl) -1,1-difluoroethanesulfonate, and the like.

Examples of the 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium salt compound include 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (3 , 5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate.

The content of the acid generator [B] in the radiation-sensitive resin composition or the radiation-sensitive resin composition for immersion exposure of the present invention is preferably 0.1 with respect to 100 parts by mass of the polymer [A]. -30 parts by mass, more preferably 2-27 parts by mass, still more preferably 5-25 parts by mass. When the content of the acid generator [B] is within this range, the sensitivity and developability of the formed photoresist film can be maintained high. In addition, when there is too little content of acid generator [B], a sensitivity and resolution may not be enough. On the other hand, when there is too much content of acid generator [B], the applicability | paintability of a composition is not enough and a favorable pattern shape may not be obtained.

1-3. Polymer [C]
The polymer [C] contained in the radiation-sensitive resin composition of the present invention is a polymer containing a fluorine atom and has a higher fluorine atom content than the polymer [A]. The fluorine atom content is preferably 5% by mass or more, more preferably 5 to 40% by mass, still more preferably 8 to 30% by mass, particularly preferably 100% by mass of the entire polymer [C]. 10 to 20% by mass. When a photoresist film is formed using the radiation sensitive resin composition of the present invention, the distribution of the polymer [C] is high on the surface of the photoresist film due to the oil repellency of the polymer [C]. Tend to be. That is, the polymer [C] tends to be unevenly distributed on the outermost surface of the photoresist film. Therefore, for the purpose of blocking the photoresist film and the immersion medium, it is not necessary to form an immersion upper layer film on the photoresist film, and it can be suitably used for the immersion exposure method as it is.
In order to sufficiently exert the effect of the present invention, the difference between the fluorine atom content in the polymer [A] and the fluorine atom content in the polymer [C] is preferably 1 mass. % Or more, more preferably 3% by mass or more, and particularly preferably 5% by mass or more.

The polymer [C] is a polymer containing at least a repeating unit containing a fluorine atom, and may have a repeating unit containing no fluorine atom.
The repeating unit containing a fluorine atom is preferably at least one repeating unit selected from the group consisting of repeating units represented by the following general formulas (c1-1) to (c1-3) (hereinafter these are combined) "Repeating unit (III-1)").

(Wherein R ²¹ represents a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, R ²² represents a fluorinated hydrocarbon group having 1 to 30 carbon atoms, and R ²³ represents Independently a hydrogen atom, a fluorine atom or a fluorinated hydrocarbon group having 1 to 30 carbon atoms, R ²⁴ is a hydrogen atom, an acid dissociable group or an alkali dissociable group, and Q ³ is (g + 1) Q ⁴ is a divalent linking group and g is 1, 2 or 3. provided that in formulas (c1-2) and (c1-3), all R ²³ Is not a hydrogen atom.)

1-3-1. Repeating unit (III-1)
The polymer [C] is a repeating unit represented by the general formula (c1-1) (hereinafter referred to as “repeating unit (III-1-1)”), represented by the general formula (c1-2). Repeating units (hereinafter referred to as “repeating units (III-1-2)”) and repeating units represented by the above general formula (c1-3) (hereinafter referred to as “repeating units (III-1-3)”. In the case of containing at least one repeating unit (III-1) selected from the group consisting of :) an acid generator [B] in a photoresist film, and an acid diffusion inhibitor contained as necessary And the like can be prevented from eluting into the immersion exposure liquid. In addition, the receding contact angle of the immersion exposure liquid on the surface of the photoresist film can be increased, so that droplets derived from the immersion exposure liquid are less likely to remain on the photoresist film. Generation of defects due to the liquid can be suppressed.

1-3-1. Repeating unit (III-1-1)
This repeating unit (III-1-1) is a repeating unit represented by the above general formula (c1-1).
In the general formula (c1-1), R ²¹ represents a hydrogen atom, a trifluoromethyl group, or an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, tert-butyl group and the like. . R ¹ is preferably a hydrogen atom or a methyl group.

In the general formula (c1-1), R ²² is a fluorinated hydrocarbon group having 1 to 30 carbon atoms, and at least one hydrogen atom in the hydrocarbon group having 1 to 30 carbon atoms is a fluorine atom. It is a group formed by substitution.
R ²² is preferably a linear or branched alkyl group having 1 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; at least one hydrogen atom is substituted with a fluorine atom And a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative group thereof.

Examples of the linear or branched alkyl group having 1 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and 1-butyl. Group, 2-butyl group, 2- (2-methylpropyl) group, 1-pentyl group, 2-pentyl group, 3-pentyl group, 1- (2-methylbutyl) group, 1- (3-methylbutyl) group, 2- (2-methylbutyl) group, 2- (3-methylbutyl) group, neopentyl group, 1-hexyl group, 2-hexyl group, 3-hexyl group, 1- (2-methylpentyl) group, 1- (3 -Methylpentyl) group, 1- (4-methylpentyl) group, 2- (2-methylpentyl) group, 2- (3-methylpentyl) group, 2- (4-methylpentyl) group, 3- (2 -Methylpentyl) group, 3- (3-methyl Rupenchiru) at least one of the hydrogen atoms in a linear or branched alkyl group such as a group has been substituted with fluorine atom, a partially fluorinated alkyl group and perfluoroalkyl group.

Examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom include a cyclopentyl group, a cyclopentylmethyl group, a 1- (1-cyclopentylethyl) group, 1- (2-cyclopentylethyl) group, cyclohexyl group, cyclohexylmethyl group, 1- (1-cyclohexylethyl) group, 1- (2-cyclohexylethyl group), cycloheptyl group, cycloheptylmethyl group, 1- (1 -Cycloheptylethyl) group, 1- (2-cycloheptylethyl) group, 2-norbornyl group, bicyclo [2.2.1] heptyl group, bicyclo [2.2.1] octyl group, tricyclo [5.2 1.0 ^2,6 ] decanyl group, tricyclo [3.3.1.1 ^3,7 ] decanyl group, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecanyl group, adamantyl group and the like, a partially fluorinated alkyl group and a perfluoroalkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
In addition, as a derivative group of the partially fluorinated alkyl group, a hydrogen atom contained in these groups is substituted with a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a 2-methylpropyl group, 1 -A group substituted with one or more linear, branched or cyclic alkyl groups having 1 to 10 carbon atoms such as methylpropyl group and tert-butyl group.

Monomers that give the repeating unit (III-1-1) represented by the general formula (c1-1) include trifluoromethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) ) Acrylic acid ester, Perfluoroethyl (meth) acrylic acid ester, Perfluoro n-propyl (meth) acrylic acid ester, Perfluoroisopropyl (meth) acrylic acid ester, Perfluoro n-butyl (meth) acrylic acid ester, Per Fluoroisobutyl (meth) acrylic acid ester, perfluoro tert-butyl (meth) acrylic acid ester, 2- (1,1,1,3,3,3-hexafluoropropyl) (meth) acrylic acid ester, 1- ( 2,2,3,3,4,4,5,5-octafluoropentyl) (meth) acrylic acid ester Perfluorocyclohexylmethyl (meth) acrylate, 1- (2,2,3,3,3-pentafluoropropyl) (meth) acrylate, 1- (3,3,4,4,5,5 , 6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl) (meth) acrylic acid ester, 1- (5-trifluoromethyl-3,3,4, 4,5,6,6,6-octafluorohexyl) (meth) acrylic acid ester and the like.

The polymer [C] may contain only one type of repeating unit (III-1-1), or may contain two or more types.

1-3-1-2. Repeating units (III-1-2) and (III-1-3)
These repeating units (III-1-2) and (III-1-3) are repeating units represented by the above general formulas (c1-2) and (c1-3), respectively.
In the general formula (c1-2) and ^{(c1-3), R 21} can be directly applied to the description of ^{R 21} in formula (c1-1).

In the above general formulas (c1-2) and (c1-3), when R ²³ is a hydrogen atom, a fluorine atom or a fluorinated hydrocarbon group having 1 to 30 carbon atoms, and all R ²³ are hydrogen atoms There is no. The plurality of R ²³ may be the same as or different from each other.
When R ²³ is a fluorinated hydrocarbon group having 1 to 30 carbon atoms, the description of R ²² can be applied as it is.

In the general formulas (c1-2) and (c1-3), the partial structure containing R ²³ represented by the following general formula includes the structures represented by the following formulas (1) to (5): can do.

Of the structures represented by the above formula, in the general formula (c1-2), the structure represented by the above formula (5) is preferable, and in the above general formula (c1-3), the above formula (3) The structure represented by these is preferable.

In the above general formulas (c1-2) and (c1-3), R ²⁴ is a hydrogen atom, an acid dissociable group or an alkali dissociable group.
Here, the “alkali dissociable group” refers to a group that substitutes a hydrogen atom in a polar functional group such as a hydroxyl group or a carboxyl group and dissociates in the presence of an alkali.

When the polymer [C] is a polymer containing the repeating unit (c1-2) and / or the repeating unit (c1-3), and these repeating units contain an acid dissociable group The solubility of the polymer [C] contained in the exposed part of the photoresist film can be improved, which is preferable. This is because in the exposure step in the resist pattern forming method described later, the acid generated in the exposed portion of the photoresist film reacts with the acid dissociable group contained in the polymer [C] to generate a polar group. it is conceivable that.

Further, when the polymer [C] is a polymer containing the repeating unit (c1-2) and / or the repeating unit (c1-3), and these repeating units contain an alkali dissociable group In this case, the affinity of the polymer [C] for the developer can be improved, which is preferable. This is considered to be because the polymer [C] reacts with the developer to generate a polar group in the development step in the pattern forming method described later.

Examples of the acid dissociable group include a tert-butoxycarbonyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, a (thiotetrahydropyranylsulfanyl) methyl group, a (thiotetrahydrofuranylsulfanyl) methyl group, an alkoxy-substituted methyl group, and an alkylsulfanyl group. Substituted methyl group, general formula [—C (R ²⁹ ) ₃ ] (wherein R ²⁹ are each independently a linear or branched alkyl group having 1 to 4 carbon atoms, and having 4 to 20 carbon atoms. A monovalent alicyclic hydrocarbon group or a derivative group thereof, and a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms formed by bonding two R ²⁹ to each other Or a derivative group thereof).

Examples of the alkoxyl group (substituent) in the alkoxy-substituted methyl group include an alkoxyl group having 1 to 4 carbon atoms, that is, a methoxy group, an ethoxy group, an n-propoxy group, and an n-butoxy group.
Examples of the alkyl group (substituent) in the alkylsulfanyl-substituted methyl group include an alkyl group having 1 to 4 carbon atoms, that is, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and the like.

In the general formula [—C (R ²⁹ ) ₃ ], which is the acid dissociable group, R ²⁹ is a linear or branched alkyl group having 1 to 4 carbon atoms, or 1 having 4 to 20 carbon atoms. A valent alicyclic hydrocarbon group or a derivative group thereof.

Examples of the linear and branched alkyl group having 1 to 4 carbon atoms represented by R ²⁹ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a 2-methylpropyl group, 1 -Methylpropyl group, tert-butyl group and the like.
Examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms represented by R ²⁹ include a cyclopentyl group, a cyclopentylmethyl group, a 1- (1-cyclopentylethyl) group, and 1- (2-cyclopentylethyl). ) Group, cyclohexyl group, cyclohexylmethyl group, 1- (1-cyclohexylethyl) group, 1- (2-cyclohexylethyl group), cycloheptyl group, cycloheptylmethyl group, 1- (1-cycloheptylethyl) group, 1- (2-cycloheptylethyl) group, 2-norbornyl group, bicyclo [2.2.1] heptyl group, bicyclo [2.2.1] octyl group, tricyclo [5.2.1.0 ^2,6 ] Decanyl group, tricyclo [3.3.1.1 ^3,7 ] decanyl group, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecanyl group, alicyclic alkyl group such as adamantyl group, and the like. Of these, alicyclic hydrocarbon groups composed of alicyclic rings derived from norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclopentane or cyclohexane are preferred.

When R ²⁹ is a derivative group of the alicyclic hydrocarbon group, R ²⁹ represents a hydrogen atom contained in the alicyclic hydrocarbon group as a methyl group, an ethyl group, an n-propyl group, an isopropyl group. 1 or more or 1 or more of linear, branched or cyclic alkyl groups having 1 to 4 carbon atoms such as a group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group and tert-butyl group Or a group substituted with or the like.

Further, the general formula [—C (R ²⁹ ) ₃ ] is a divalent alicyclic carbon atom having 4 to 20 carbon atoms formed by bonding any two of three R ²⁹ to each other. It may have a hydrogen group and a derivative group thereof, and examples thereof include a bridged skeleton such as an adamantane skeleton, a norbornane skeleton, a tricyclodecane skeleton, a tetracyclododecane skeleton, a cyclobutylene group, a cyclopentylene group, Divalent monocyclic hydrocarbon groups such as cyclohexylene group, cycloheptylene group, cyclooctylene group; the hydrogen atoms contained in these groups are methyl, ethyl, n-propyl, isopropyl, n- Substituted with one or more linear, branched or cyclic alkyl groups having 1 to 4 carbon atoms such as butyl, 2-methylpropyl, 1-methylpropyl and tert-butyl. Groups having an alicyclic skeleton such groups. Among these, a divalent monocyclic hydrocarbon group such as a cyclopentylene group or a cyclohexylene group, or a hydrogen atom contained in the alicyclic hydrocarbon group (monocyclic hydrocarbon group) is represented by the number of carbon atoms. A group substituted with one or more of 1 to 4 linear, branched or cyclic alkyl groups is preferred.

Preferred examples of the general formula [—C (R ²⁹ ) ₃ ] include a tert-butyl group, a 1-n- (1-ethyl-1-methyl) propyl group, and a 1-n- (1,1-dimethyl) group. Propyl group, 1-n- (1,1-dimethyl) butyl group, 1-n- (1,1-dimethyl) pentyl group, 1- (1,1-diethyl) propyl group, 1-n- (1, 1-diethyl) butyl group, 1-n- (1,1-diethyl) pentyl group, 1- (1-methyl) cyclopentyl group, 1- (1-ethyl) cyclopentyl group, 1- (1-n-propyl) Cyclopentyl group, 1- (1-isopropyl) cyclopentyl group, 1- (1-methyl) cyclohexyl group, 1- (1-ethyl) cyclohexyl group, 1- (1-n-propyl) cyclohexyl group, 1- (1- Isopropyl) cyclohexyl group, 1 -{1-methyl-1- (2-norbornyl)} ethyl group, 1- {1-methyl-1- (2-tetracyclodecanyl)} ethyl group, 1- {1-methyl-1- (1- Adamantyl)} ethyl group, 2- (2-methyl) norbornyl group, 2- (2-ethyl) norbornyl group, 2- (2-n-propyl) norbornyl group, 2- (2-isopropyl) norbornyl group, 2- (2-methyl) tetracyclodecanyl group, 2- (2-ethyl) tetracyclodecanyl group, 2- (2-n-propyl) tetracyclodecanyl group, 2- (2-isopropyl) tetracyclodecanyl group Groups, 1- (1-methyl) adamantyl group, 1- (1-ethyl) adamantyl group, 1- (1-n-propyl) adamantyl group, 1- (1-isopropyl) adamantyl group, and these groups Hydrogen atom Straight chain, branched or straight chain having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, tert-butyl group, etc. And a group substituted with one or more cyclic alkyl groups.

The acid dissociable group is preferably a group represented by the above general formula [—C (R ²⁹ ) ₃ ], a tert-butoxycarbonyl group, an alkoxy-substituted methyl group, or the like.
In the repeating unit (c1-2), a tert-butoxycarbonyl group and an alkoxy-substituted methyl group are preferable.
In the repeating unit (c1-3), an alkoxy-substituted methyl group and a group represented by the above general formula [—C (R ²⁹ ) ₃ ] are preferable.

The alkali-dissociable group is not particularly limited as long as it exhibits the above properties. Examples of the alkali dissociable group in the general formula (c1-2) include groups represented by the following general formula (R1-1).

(Wherein R ³⁰ is a fluorinated hydrocarbon group having 1 to 10 carbon atoms.)

In the general formula (R1-1), R ³⁰ is a fluorinated hydrocarbon group having 1 to 10 carbon atoms, and at least one hydrogen atom in the hydrocarbon group having 1 to 10 carbon atoms is substituted with a fluorine atom. It is a group consisting of R ³⁰ is preferably a linear or branched perfluoroalkyl group having 1 to 10 carbon atoms, and particularly preferably a trifluoromethyl group.

In addition, examples of the alkali dissociable group in the general formula (c1-3) include groups represented by the following general formulas (R1-2) to (R1-4).

(Wherein R ^{31 s} are independently of each other a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, an acyl group having 1 to 10 carbon atoms, or an acyloxy group having 1 to 10 carbon atoms. R ³³ is, independently of each other, a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and is a divalent carbon atom formed by bonding two R ³³ together, It may be an alicyclic hydrocarbon having 4 to 20 or a derivative group thereof, m1 is 0, 1, 2, 3, 4 or 5, and m2 is 0, 1, 2, 3 or 4. is there.)

In the above general formulas (R1-2) and (R1-3), when R ³¹ is a halogen atom, it can be a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. Of these, fluorine atoms are preferred.

In the above general formulas (R1-2) and (R1-3), the alkyl group having 1 to 10 carbon atoms represented by R ³¹ includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and 1-butyl. Group, 2-butyl group, 2- (2-methylpropyl) group, 1-pentyl group, 2-pentyl group, 3-pentyl group, 1- (2-methylbutyl) group, 1- (3-methylbutyl) group, 2- (2-methylbutyl) group, 2- (3-methylbutyl) group, neopentyl group, 1-hexyl group, 2-hexyl group, 3-hexyl group, 1- (2-methylpentyl) group, 1- (3 -Methylpentyl) group, 1- (4-methylpentyl) group, 2- (2-methylpentyl) group, 2- (3-methylpentyl) group, 2- (4-methylpentyl) group, 3- (2 -Methylpentyl) group, 3- (3-methylpe Straight chain and branched alkyl groups such as 1-heptyl group, 1-heptyl group, 1-octyl group, 1-nonyl group and 1-decyl group.

Examples of the alkoxyl group having 1 to 10 carbon atoms represented by R ³¹ include methoxy group, ethoxy group, n-propoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, n-pentyloxy group, n- Examples thereof include linear and branched alkyl groups such as a hexyloxy group.

Examples of the acyl group having 1 to 10 carbon atoms represented by R ³¹ include acetyl group, propionyl group, methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, isopropoxycarbonyl group, n-butoxycarbonyl group, isobutoxy group. Examples include carbonyl group, sec-butoxycarbonyl group, tert-butoxycarbonyl group, n-pentoxycarbonyl group, n-hexyloxycarbonyl group, n-heptyloxycarbonyl group, n-octyloxycarbonyl group and the like.

Examples of the acyloxy group having 1 to 10 carbon atoms represented by R ³¹ include an acetoxy group, an ethylyloxy group, a butyryloxy group, a tert-butyryloxy group, a tert-amylyloxy group, an n-hexanecarbonyloxy group, and an n-octanecarboxyl group. Examples include a nitroxy group.

In the general formula (R1-2) and ^{(R1-3), if R 31} is two or ^{more, R 31} may or be identical to each other or may be different.

In the above general formula (R1-4), R ³³ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.
When R ³³ is an alkyl group having 1 to 10 carbon atoms, methyl group, ethyl group, n-propyl group, isopropyl group, 1-butyl group, 2-butyl group, 2- (2-methylpropyl) group, 1-pentyl group, 2-pentyl group, 3-pentyl group, 1- (2-methylbutyl) group, 1- (3-methylbutyl) group, 2- (2-methylbutyl) group, 2- (3-methylbutyl) group , Neopentyl group, 1-hexyl group, 2-hexyl group, 3-hexyl group, 1- (2-methylpentyl) group, 1- (3-methylpentyl) group, 1- (4-methylpentyl) group, 2 -(2-methylpentyl) group, 2- (3-methylpentyl) group, 2- (4-methylpentyl) group, 3- (2-methylpentyl) group, 3- (3-methylpentyl) group, 1 -Heptyl group, 1-octyl group, 1-nonyl group And linear and branched alkyl groups such as 1-decyl group.

In addition, examples of the divalent alicyclic hydrocarbon having 4 to 20 carbon atoms formed by bonding two R ³³ to each other in the general formula (R1-4) include an adamantane skeleton and a norbornane skeleton. And a bridged skeleton such as a tricyclodecane skeleton and a tetracyclododecane skeleton, and a group having a cycloalkane skeleton such as cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane. Further, in the case of the derivative group of the alicyclic hydrocarbon group, the hydrogen atom contained in the alicyclic hydrocarbon group is a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, 2 -A group substituted with one or more linear, branched or cyclic alkyl groups having 1 to 4 carbon atoms such as methylpropyl group, 1-methylpropyl group, tert-butyl group, etc. Can do.

Examples of the group represented by the general formula (R1-4) include a methyl group, an ethyl group, a 1-propyl group, a 2-propyl group, a 1-butyl group, a 2-butyl group, a 1-pentyl group, and a 2-pentyl group. Group, 3-pentyl group, 1- (2-methylbutyl) group, 1- (3-methylbutyl) group, 2- (3-methylbutyl) group, neopentyl group, 1-hexyl group, 2-hexyl group, 3-hexyl Group, 1- (2-methylpentyl) group, 1- (3-methylpentyl) group, 1- (4-methylpentyl) group, 2- (3-methylpentyl) group, 2- (4-methylpentyl) group Group, 3- (2-methylpentyl) group and the like. Of these, methyl, ethyl, 1-propyl, 2-propyl, 1-butyl and 2-butyl are preferred.

In the general formulas (c1-2) and (c1-3), the repeating unit (III-1-2) and the repeating unit (III-1-3) in which R ²⁴ is a hydrogen atom are polar groups. It will have some hydroxyl or carboxyl group. When the polymer [C] contains such a repeating unit, the affinity of the polymer [C] for the developer can be improved in the development step of the pattern forming method described later.

In the above general formula (c1-2), Q ³ is a (g + 1) -valent linking group. Examples of such a group include a single bond, a (g + 1) valent hydrocarbon group having 1 to 30 carbon atoms and a derivative group thereof.

The (g + 1) -valent hydrocarbon group can be a group including a chain structure or a cyclic structure.
Chain structure hydrocarbon groups include methane, ethane, propane, butane, 2-methylpropane, pentane, 2-methylbutane, 2,2-dimethylpropane, hexane, heptane, octane, nonane, decane, etc. A hydrocarbon group having a structure in which (g + 1) hydrogen atoms are removed from 1 to 10 chain hydrocarbons can be obtained.
Examples of the cyclic hydrocarbon group include cyclobutane, cyclopentane, cyclohexane, bicyclo [2.2.1] heptane, bicyclo [2.2.2] octane, and tricyclo [5.2.1.0 ^2,6. ] An alicyclic hydrocarbon group having a structure in which (g + 1) hydrogen atoms are removed from an alicyclic hydrocarbon having 4 to 20 carbon atoms such as decane, tricyclo [3.3.1.1 ^3,7 ] decane, etc. An aromatic hydrocarbon group having a structure in which (g + 1) hydrogen atoms are removed from an aromatic hydrocarbon having 6 to 30 carbon atoms, such as benzene and naphthalene.

Further, Q ³ in the general formula (c1-2) may be a derivative group of the hydrocarbon group, and an oxygen atom, a sulfur atom, an imino group, a carbonyl group, —CO—O— or —CO—NH—. It can be set as the group provided with.
Examples of Q ³ having an oxygen atom, a sulfur atom, an imino group, a carbonyl group, —CO—O— or —CO—NH— include groups represented by the following general formula.

(Wherein, R ^{61 s} are independently of each other a single bond, divalent, an aliphatic hydrocarbon group having 1 to 10 carbon atoms or a derivative group thereof, divalent, and having 4 to 20 carbon atoms. An alicyclic hydrocarbon group or a derivative group thereof, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a derivative group thereof, and g is 1, 2, or 3.

Examples of the divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms represented by R ⁶¹ in the above general formula include a methylene group, an ethylene group, a 1,3-propylene group, and a 1,2-propylene group. Propylene group, tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, 1-methyl-1,3-propylene group, 2-methyl-1 , 3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl-1,4-butylene group and the like.

In the above general formula, the divalent and alicyclic hydrocarbon group having 4 to 20 carbon atoms represented by R ⁶¹ includes a cyclobutylene group such as 1,3-cyclobutylene group, 1,3- 3 to 10 carbon atoms, such as a cyclopentylene group such as a cyclopentylene group, a cyclohexylene group such as a 1,4-cyclohexylene group, and a cyclooctylene group such as a 1,5-cyclooctylene group Monocyclic hydrocarbon ring groups such as cycloalkylene groups; norbornylene groups such as 1,4-norbornylene groups and 2,5-norbornylene groups, adamantylene groups such as 1,5-adamantylene groups and 2,6-adamantylene groups And a bridged cyclic hydrocarbon group such as a 2 to 4 cyclic hydrocarbon ring group having 4 to 20 carbon atoms, such as a group.

In the above general formula, the divalent aromatic hydrocarbon group represented by R ⁶¹ having 6 to 30 carbon atoms is obtained by removing two hydrogen atoms from an aromatic hydrocarbon such as benzene or naphthalene. It can be an aromatic hydrocarbon group having a different structure.

In addition, as described above, any of the chain hydrocarbon group, the cyclic hydrocarbon group, and the aromatic hydrocarbon group can be a derivative group, and at least one hydrogen atom contained in the hydrocarbon group is methylated. Linear, branched or cyclic having 1 to 10 carbon atoms such as a group, ethyl group, n-propyl group, isopropyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, tert-butyl group Groups having an alicyclic skeleton such as one or more alkyl groups substituted with one or more alkyl groups.

In the general formula (c1-2), g is 1, 2 or 3, and when g is 2 or 3, a plurality of structural parts represented by the following general formula in the general formula (c1-2) May be the same as or different from each other.

(Wherein R ²³ is independently of each other a hydrogen atom, a fluorine atom or a fluorinated hydrocarbon group having 1 to 30 carbon atoms, and R ²⁴ is a hydrogen atom, an acid dissociable group or an alkali dissociable group. is there.)

Q ⁴ in the general formula (c1-3) can be the same as Q ³ when g in the general formula (c1-3) is 1.

The repeating unit (III-1-2) represented by the general formula (c1-2) is exemplified by the following general formula.

(Wherein R ²¹ is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, R ²⁴ is a hydrogen atom, an acid dissociable group or an alkali dissociable group, and Q ³ is (G + 1) is a valent linking group, and g is 1, 2 or 3.)

Examples of the monomer that gives the repeating unit (III-1-2) represented by the general formula (c1-2) are exemplified by the following general formula.

(Wherein R ²¹ is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, and R ²⁴ is a hydrogen atom, an acid dissociable group or an alkali dissociable group.)

In the five types of monomers represented by the above general formula, the compound in which R ²⁴ is an acid dissociable group or an alkali dissociable group uses, for example, a compound in which R ²⁴ in the above general formula is a hydrogen atom as a raw material. Can be synthesized.
And R ²⁴ is an alkali dissociative group, for example, as a synthesis method of a monomer having the structure represented by the general formula (R1-1), the compound R ²⁴ is a hydrogen atom in the above general formula And a method of fluoroacylation. Specific methods are exemplified below.
(1) A method in which an alcohol and a fluorocarboxylic acid are condensed and esterified in the presence of an acid. (2) A method in which an alcohol and a fluorocarboxylic acid halide are condensed and esterified in the presence of a base.

The repeating unit (III-1-3) represented by the general formula (c1-3) is exemplified by the following general formula.

(Wherein R ²¹ is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, R ²⁴ is a hydrogen atom, an acid-dissociable group or an alkali-dissociable group, and Q ⁴ is It is a divalent linking group.)

Examples of the monomer that gives the repeating unit (III-1-3) represented by the general formula (c1-3) are exemplified by the following general formula.

In the four types of monomers represented by the above general formula, the compound in which R ²⁴ is an acid dissociable group or an alkali dissociable group is, for example, a compound in which R ²⁴ in the above general formula is a hydrogen atom, or It can be synthesized by using a derivative compound as a raw material.
A monomer having a structure represented by the general formulas (R1-2) to (R1-4) wherein R ²⁴ is an alkali-dissociable group is represented by the following general formula (m-2-3): It can be synthesized by reacting the compound represented by the following general formulas (m-2-4-1) to (m-2--4-3).

(Wherein R ²¹ is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, and R ²³ is independently a hydrogen atom, a fluorine atom or a fluorinated group having 1 to 30 carbon atoms. (It is a hydrocarbon group, R ⁵¹ is a halogen atom or a hydroxyl group, Q ⁴ is a divalent linking group, and two R ²³ are not hydrogen atoms.)

(Wherein R ^{31 s} are independently of each other a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, an acyl group having 1 to 10 carbon atoms, or an acyloxy group having 1 to 10 carbon atoms. R ⁵⁵ is a halogen atom, R ⁵⁶ is a halogen atom, m1 is 0, 1, 2, 3, 4 or 5, and m2 is 0, 1, 2, 3 or 4)

In the above general formula (m-2-4-1), R ⁵⁵ is preferably a chlorine atom. In the general formula (m-2-4-2), R ⁵⁶ is preferably a bromine atom.

In addition, R ²⁴ is an alkali dissociable group and, for example, a monomer having a structure represented by the above general formulas (R1-2) to (R1-4) is represented by the following general formula (m-2-5) ) And a compound represented by the following general formula (m-2-6) can be synthesized.

(Wherein R ²¹ is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, and R ²³ is independently a hydrogen atom, a fluorine atom or a fluorinated group having 1 to 30 carbon atoms. A hydrocarbon group, R ²⁴ is a hydrogen atom, an acid dissociable group or an alkali dissociable group, R ⁵⁹ is a halogen atom or a hydroxyl group, and Q ⁴ is a divalent linking group. In the formula (m-2-5), two R ²³ are not hydrogen atoms.)

As described above, the polymer [C] contains at least one repeating unit (III) selected from repeating units (III-1-1), (III-1-2) and (III-1-3). A polymer containing -1) is preferred. Each of the repeating units (III-1) contained may be only one type, or two or more types.
In the present invention, the polymer [C] contains at least two kinds of repeating units selected from the repeating units (III-1-1), (III-1-2) and (III-1-3). A polymer is more preferable, and a polymer including repeating units (III-1-2) and (III-1-3) is particularly preferable.

The content of the repeating unit (III-1) constituting the polymer [C] is preferably 20 to 90 mol% with respect to 100 mol% in total of all the repeating units constituting the polymer [C]. More preferably, it is 30 to 90 mol%, still more preferably 30 to 85 mol%. When the content of the repeating unit (III-1) is within this range, it is particularly effective from the viewpoint of ensuring water repellency after coating and compatibility of contact angle with the developer after PEB.

1-3-2. Other Repeating Units The polymer [C] includes, in addition to the repeating unit (III-1), a repeating unit having an acid dissociable group (hereinafter referred to as “repeating unit (III-2)”), an alkali-soluble group. And a repeating unit having a lactone skeleton or a cyclic carbonate skeleton (hereinafter referred to as “repeating unit (III-4)”) and the like. But you can.

1-3-2-1. Repeating unit (III-2)
By including this repeating unit (III-2) in the polymer [C], the difference between the advancing contact angle and the receding contact angle in the photoresist film can be reduced, and the scanning speed during exposure can be improved. Can respond more.

The repeating unit (III-2) is preferably a repeating unit represented by the following general formula (c2-1).

(Wherein R ²⁵ is a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group, R ²⁶ is a linear or branched alkyl group having 1 to 4 carbon atoms, and k is 1, 2, 3 or 4.)

In the general formula (c2-1), the linear or branched alkyl group having 1 to 4 carbon atoms represented by R ²⁶ includes a methyl group, ethyl group, n-propyl group, isopropyl group, n- Examples thereof include a butyl group, a 2-methylpropyl group, a 1-methylpropyl group, and a tert-butyl group.

The polymer [C] may contain the repeating unit (III-2) alone or in combination of two or more.

When the polymer [C] contains the repeating unit (III-2), the content thereof is preferably 80 mol with respect to 100 mol% in total of all the repeating units constituting the polymer [C]. % Or less, more preferably 10 to 80 mol%, still more preferably 20 to 80 mol%, particularly preferably 30 to 70 mol%. When the content of the repeating unit (III-2) is in the above range, the difference between the advancing contact angle and the receding contact angle in the photoresist film can be reduced.

1-3-2-2. Repeating unit (III-3)
By including this repeating unit (III-3) in the polymer [C], the solubility of the photoresist film can be improved in the development step of the pattern forming method described later.

The alkali-soluble group in the repeating unit (III-3) is preferably a functional group having a hydrogen atom having a pKa of 4 to 11.

Examples of the alkali-soluble group include the following general formula (c3-a) and formula (c3-b).

(Wherein R ³⁶ is a fluorinated hydrocarbon group having 1 to 10 carbon atoms.)

In the general formula (c3-a), R ³⁶ is a fluorinated hydrocarbon group having 1 to 10 carbon atoms, and at least one hydrogen atom in the hydrocarbon group having 1 to 10 carbon atoms is substituted with a fluorine atom. It is a group consisting of In the present invention, R ³⁶ is preferably a trifluoromethyl group.

The structure of the main chain in the repeating unit (III-3) is not particularly limited, but is preferably the structure of the main chain in a polymer such as (meth) acrylic acid ester or α-trifluoroacrylic acid ester.

The repeating unit (III-3) is exemplified by the following general formulas (c3-a-1) and (c3-b-1).

(Wherein R ²⁷ is a hydrogen atom, a methyl group or a trifluoromethyl group, and R ²⁸ is a single bond, or a divalent, linear, branched or cyclic group having 1 to 20 carbon atoms. S ³⁶ is a saturated or unsaturated hydrocarbon group, and R ³⁶ is a fluorinated hydrocarbon group having 1 to 10 carbon atoms.)

R ²⁸ in the above general formulas (c3-a-1) and (c3-b-1) is divalent and has 1 to 20 carbon atoms, linear, branched or cyclic, saturated or unsaturated. When it is a hydrocarbon group, specific examples thereof include a methylene group, an ethylene group, a 1,3-propylene group and a 1,2-propylene group, a propylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group. , Heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, pentadecamethylene group, hexadecamethylene group, heptacamethylene group, octa Decamethylene group, nonacamethylene group, insalen group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene Group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl-1,4-butylene group, methylidene group, ethylidene group, propylidene group, 2-propylidene group, etc. A saturated chain hydrocarbon group; a cyclobutylene group such as 1,3-cyclobutylene group, a cyclopentylene group such as 1,3-cyclopentylene group, and a cyclohexylene group such as 1,4-cyclohexylene group A monocyclic hydrocarbon ring group such as a cycloalkylene group having 3 to 10 carbon atoms such as a cyclooctylene group such as 1,5-cyclooctylene group; 1,4-norbornylene group, 2,5-norbornylene A bridged cyclic group such as a 2-4 cyclic hydrocarbon ring group having 4 to 30 carbon atoms, such as a norbornylene group such as a group, adamantylene group such as 1,5-adamantylene group, 2,6-adamantylene group, etc. Hydrocarbon group, etc. And the like.

The polymer [C] may contain the repeating unit (III-3) alone or in combination of two or more.

When the polymer [C] contains the repeating unit (III-3), the content thereof is preferably 50 mol with respect to 100 mol% in total of all the repeating units constituting the polymer [C]. % Or less, more preferably 5 to 30 mol%, still more preferably 5 to 20 mol%. When the content of the repeating unit (III-3) is in the above range, the solubility of the photoresist film can be improved in the development step of the pattern forming method described later.

1-3-2-3. Repeating unit (III-4)
By including this repeating unit (III-4) in the polymer [C], it is possible to improve the hydrophilicity during alkali development while ensuring the hydrophobicity of the photoresist film during immersion exposure. Repeating unit that can be.

When the polymer [C] contains the repeating unit (III-4), the content thereof is preferably 50 mol with respect to 100 mol% in total of all the repeating units constituting the polymer [C]. % Or less, more preferably 5 to 30 mol%, still more preferably 5 to 20 mol%. When the content of the repeating unit (III-4) is in the above range, the hydrophilicity during alkali development can be improved while ensuring the hydrophobicity of the photoresist film during immersion exposure.

1-3-2-4. Preferred combinations of repeating units The combinations of repeating units constituting the polymer [C] and their contents are shown below.
It consists of the repeating unit (III-1) and the repeating unit (III-2), and the content thereof is preferably respectively based on 100 mol% in total of all the repeating units constituting the polymer [C]. Are polymers of 20 to 90 mol% and 10 to 80 mol%, more preferably 30 to 90 mol% and 10 to 70 mol%.

1-3-3. Average Molecular Weight The weight average molecular weight (Mw) of the polymer [C] is preferably 1,000 to 50,000, more preferably 1,000 to 40,000, and still more preferably 1,000 in terms of polystyrene by GPC. ~ 30,000. If Mw is less than 1,000, a photoresist film having a sufficient receding contact angle may not be obtained. On the other hand, if Mw exceeds 50,000, the developability of the photoresist film may deteriorate.
Further, the ratio (Mw / Mn) obtained using the number average molecular weight (Mn) in terms of polystyrene by GPC and Mw is preferably 1 to 5, more preferably 1 to 4.

1-3-4. Production Method The above polymer [C] is a single monomer that will form the repeating unit (III-1) in the presence of a radical polymerization initiator such as hydroperoxide, dialkyl peroxide, diacyl peroxide, and azo compound. It can manufacture by polymerizing the monomer raw material containing a body in a suitable solvent. In the polymerization system, a chain transfer agent may coexist if necessary.
The polymerization temperature is usually 40 ° C. to 150 ° C., preferably 50 ° C. to 120 ° C. The polymerization time is usually 1 to 48 hours, preferably 1 to 24 hours.

In addition, in polymer [C] used for manufacture of the radiation sensitive resin composition of this invention, it is so preferable that there is little content of impurities, such as a halogen and a metal. When the content of such impurities is small, the sensitivity, resolution, process stability, pattern shape and the like of the photoresist film can be further improved. Therefore, it is preferable to subject the crude product containing the polymer [C] synthesized by the above method to purification. Examples of the purification method include chemical purification methods such as washing with water and liquid-liquid extraction, and methods combining these chemical purification methods with physical purification methods such as ultrafiltration and centrifugation.

1-3-5. Content The content of the polymer [C] in the radiation-sensitive resin composition of the present invention is preferably 0.1 to 20 parts by mass, more preferably 1 to 100 parts by mass with respect to 100 parts by mass of the polymer [A]. The amount is 10 parts by mass, more preferably 1 to 7.5 parts by mass. If the content of the polymer [C] is too small, the effect of containing the polymer [C] may not be sufficient. On the other hand, if the content of the polymer [C] is too large, the water repellency on the surface of the photoresist film becomes too high, and development failure may occur.

1-4. Additives The radiation-sensitive resin composition of the present invention or the radiation-sensitive resin composition for immersion exposure includes, in addition to the above essential components, an acid diffusion inhibitor, a lactone compound, a solvent, a surfactant, a sensitizer, and a halation. An inhibitor, an adhesion assistant, a storage stabilizer, an antifoaming agent, an alicyclic additive, and the like may be included.

1-4-1. Acid Diffusion Inhibitor This acid diffusion inhibitor controls the diffusion phenomenon of the acid generated from the acid generator [B] in the photoresist film by immersion exposure, and suppresses an undesirable chemical reaction in the unexposed area. It is a component having By blending this acid diffusion inhibitor, the shape of the patterned resist film portion to be obtained and its dimensional fidelity can be improved.

Examples of the acid diffusion inhibitor include a compound represented by the following general formula (E) (hereinafter referred to as “nitrogen-containing compound (I)”), a compound having two nitrogen atoms (hereinafter referred to as “nitrogen-containing compound (II)”. ) "), Compounds having 3 or more nitrogen atoms (hereinafter referred to as" nitrogen-containing compound (III) "), amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like. These acid diffusion inhibitors may be used alone or in combination of two or more.

(In the formula, R ⁶¹ are each independently a hydrogen atom, or a substituted or unsubstituted, linear, branched or cyclic alkyl group, aryl group or aralkyl group.)

Nitrogen-containing compounds (I) include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; di-n-butylamine, di-n-pentylamine Dialkylamines such as di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine; triethylamine, tri-n-propylamine, tri- trialkylamines such as n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine; Aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaline Phosphorus, 4-methylaniline, 4-nitroaniline, 2, 6-diisopropylaniline, diphenylamine, triphenylamine, 1-naphthylamine, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- And aromatic amines such as (4-aminophenyl) -2- (4-hydroxyphenyl) propane.

Examples of the nitrogen-containing compound (II) include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, tetramethylenediamine, hexa Methylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, 2,2′-bis (4-aminophenyl) propane, 2 -(3-aminophenyl) -2- (4-aminophenyl) propane, 1,4-bis [1- (4-aminophenyl) -1-methylethyl] benzene, 1,3-bis [1- (4 -Aminophenyl) -1-methylethyl] benzene and the like.

Examples of the nitrogen-containing compound (III) include polymers of polyethyleneimine, polyallylamine, dimethylaminoethylacrylamide, and the like.

Examples of the amide group-containing compound include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone and the like. It is done.

Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tributylthiourea and the like.

Examples of the nitrogen-containing heterocyclic compound include pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, N-methyl-4-phenylpyridine, Pyridines such as nicotine, nicotinic acid, nicotinamide, quinoline, 8-oxyquinoline, acridine; piperidines such as piperidine, tert-butyl-4-hydroxy-1-piperidinecarboxylate; pyrazine, pyrazole, pyridazine, quinosaline, Examples include purine, pyrrolidine, morpholine, 4-methylmorpholine, piperazine, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane.

As the acid diffusion inhibitor, a compound represented by the following general formula (D1-0) can also be used.
X ⁺ Z ^- (D1-0)
Wherein X ⁺ is a cation represented by the following general formula (D1-1) or (D1-2), Z ⁻ is OH ⁻ , general formula (D1-3): R ^D1 —COO ⁻ An anion represented by general formula (D1-4): R ^D1 —SO ₃ ^— , or an anion represented by general formula (D1-5): R ^D1 —N ⁻ —SO ₂ —R ^D11 that is an anion (provided that in the general formula ^{(D1-3) ~ (D1-5),} R D1 is an optionally substituted alkyl group, an alicyclic hydrocarbon group or an aryl group ^{.R D11} is , An optionally substituted fluorinated alkyl group, an alicyclic fluorinated hydrocarbon group, or a fluorinated aryl group.)

(In the general formula (D1-1), R ^D2 , R ^D3, and R ^D4 are each independently a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group, or a halogen atom. -2), R ^D5 and R ^D6 are each independently a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group, or a halogen atom.)

The compound represented by the general formula (D1-0) is used as an acid diffusion control agent that is decomposed by exposure and loses acid diffusion controllability (hereinafter also referred to as “photodegradable acid diffusion control agent”). It is. When the radiation sensitive resin composition of the present invention or the radiation sensitive resin composition for immersion exposure contains the compound represented by the general formula (D1-0), an acid diffuses in the exposed portion, Since the acid diffusion is controlled in the unexposed area, the contrast between the exposed area and the unexposed area is excellent (that is, the boundary between the exposed area and the unexposed area becomes clear). Therefore, such a composition is effective in improving LWR and MEEF (Mask Error Enhancement Factor (amplification factor of line width deviation due to mask width deviation)).

In the general formula (D1-0), X ⁺ is a cation represented by the general formula (D1-1) or (D1-2) as described above. In the general formula (D1-1), R ^D2 , R ^D3 and R ^D4 are each independently a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group or a halogen atom. Among these, a hydrogen atom, an alkyl group, an alkoxy group, and a halogen atom are preferable because the compound represented by the above formula (D1-0) has an effect of reducing solubility in a developer. In the general formula (D1-2), R ^D5 and R ^D6 are each independently a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group, or a halogen atom. Of these, a hydrogen atom, an alkyl group, and a halogen atom are preferable.

In the general formula (D1-0), Z ⁻ represents, as described above, OH ⁻ , an anion represented by the general formula (D1-3): R ^D1 —COO ^— , and the general formula (D1-4): R An anion represented by ^D1— SO ₃ ^— , or an anion represented by formula (D1-5): R ^D1 —N ^—— SO ₂ —R ^D11 (provided that the formula (D1-3) to In (D1-5), R ^D1 represents an optionally substituted alkyl group, an alicyclic hydrocarbon group, or an aryl group, and R ^D11 represents an optionally substituted fluorinated alkyl group, an alicyclic group. A fluorinated hydrocarbon group or a fluorinated aryl group).

Z ⁻ in the general formula (D1-0) is preferably an anion represented by the following formula (1a) (that is, in the anion represented by the general formula (D1-3), R ^D1 is a phenyl group. Anion), an anion represented by the following formula (1b) (ie, an anion represented by the general formula (D1-4), wherein R ^D1 is 1,7,7-trimethylbicyclo [2.2.1] heptane- An anion which is a group derived from 2-one) and an anion represented by the following formula (1c) (that is, an anion represented by the general formula (D1-5)), wherein R ^D1 is a butyl group, and R ^D11 Is an anion) which is a trifluoromethyl group.

The photodegradable acid diffusion controller is represented by the above general formula (D1-0), and specifically, is a sulfonium salt compound or an iodonium salt compound that satisfies the above conditions.

Examples of the sulfonium salt compounds include triphenylsulfonium hydroxide, triphenylsulfonium acetate, triphenylsulfonium salicylate, diphenyl-4-hydroxyphenylsulfonium hydroxide, diphenyl-4-hydroxyphenylsulfonium acetate, diphenyl-4-hydroxyphenyl. Examples thereof include sulfonium salicylate, triphenylsulfonium 10-camphor sulfonate, 4-tert-butoxyphenyl diphenylsulfonium 10-camphor sulfonate, and the like. In addition, these compounds may be used independently and may be used in combination of 2 or more.

Examples of the iodonium salt compound include bis (4-tert-butylphenyl) iodonium hydroxide, bis (4-tert-butylphenyl) iodonium acetate, bis (4-tert-butylphenyl) iodonium hydroxide, bis (4 -Tert-butylphenyl) iodonium acetate, bis (4-tert-butylphenyl) iodonium salicylate, 4-tert-butylphenyl-4-hydroxyphenyliodonium hydroxide, 4-tert-butylphenyl-4-hydroxyphenyliodonium Acetate, 4-tert-butylphenyl-4-hydroxyphenyliodonium salicylate, bis (4-tert-butylphenyl) iodonium 10-camphorsulfo Over DOO, such as diphenyl iodonium 10-camphorsulfonate, and the like. In addition, these compounds may be used independently and may be used in combination of 2 or more.
The said photodegradable acid diffusion control agent can be used individually by 1 type or in combination of 2 or more types.

As the acid diffusion inhibitor, a nitrogen-containing compound (I), a nitrogen-containing compound (II), a nitrogen-containing heterocyclic compound, and a photodegradable acid diffusion controller are preferable.

When the radiation sensitive resin composition of the present invention or the radiation sensitive resin composition for immersion exposure contains an acid diffusion inhibitor, the content thereof is preferably based on 100 parts by mass of the polymer [A]. Is 10 parts by mass or less, more preferably 5 parts by mass or less. However, the lower limit of the content is usually 0.01 parts by mass. When there is too much content of the said acid diffusion inhibitor, the sensitivity of a photoresist film may fall.

1-4-2. Solvent This solvent is preferably a solvent that can dissolve at least the polymers [A] and [C] and the acid generator [B] to bring the composition of the present invention into a solution state.
Examples of the solvent include linear or branched ketones, cyclic ketones, alkylene glycol monoalkyl ethers, alkylene glycol dialkyl ethers, alkylene glycol monoalkyl ether acetates, carboxylic acid esters, and hydroxyl groups. Examples thereof include carboxylic acid esters, carboxylic acid esters having an alkoxy group, alcohols, and aromatic hydrocarbons. In addition, these solvents may be used independently and may be used in combination of 2 or more type.

The amount of the solvent used is such that the total solid concentration of the radiation-sensitive resin composition or the radiation-sensitive resin composition for immersion exposure of the present invention is preferably 1 to 50% by mass, more preferably 1 to 25% by mass. The amount is such that
The composition of the present invention can be used as a composition solution by, for example, filtration using a filter having a pore size of about 0.2 μm.

1-4-3. Lactone compound This lactone compound is a component that imparts the effect of segregating the contained polymer [C] to the surface layer of the photoresist film in order to efficiently develop water repellency on the surface of the photoresist film in immersion exposure. It is. By using the composition containing the lactone compound, the elution of components from the photoresist film to the immersion exposure liquid is suppressed without impairing basic resist characteristics such as LWR, development defects, and pattern collapse resistance. be able to. In addition, even when immersion exposure is performed by high-speed scanning, water repellency on the surface of the photoresist film can be maintained without leaving droplets, and defective phenomena such as watermark defects can be suppressed. .

Examples of the lactone compound imparting the above action include γ-butyrolactone, valerolactone, mevalonic lactone, norbornane lactone and the like. These compounds may be used alone or in combination of two or more.

When the radiation sensitive resin composition of the present invention or the radiation sensitive resin composition for immersion exposure contains the lactone compound, the content thereof is usually 100 parts by mass of the polymer [A]. 30 to 200 parts by mass, preferably 50 to 150 parts by mass. If the content of the lactone compound is too large, the basic performance of the resist is lowered, and a pattern having a good shape may not be obtained.

The radiation-sensitive resin composition for immersion exposure according to the present invention may contain another polymer such as the polymer [C] in addition to the polymer [A].
The content of the other polymer is usually 0.1 to 20 parts by mass, preferably 1 to 10 parts by mass, more preferably 1 to 7.5 parts by mass with respect to 100 parts by mass of the polymer [A]. It is. When the other polymer is the polymer [C], if the content is too small, the effect of containing the polymer [C] may not be sufficient. On the other hand, if the content of the polymer [C] is too large, the water repellency on the surface of the photoresist film becomes too high, and development failure may occur.

The radiation-sensitive resin composition and the radiation-sensitive resin composition for immersion exposure of the present invention are particularly useful as a chemically amplified resist. In the chemically amplified resist, the acid-dissociable group in the polymer component is dissociated by the action of the acid generated from the acid generator [B] by exposure to generate a carboxyl group. As a result, the exposed portion of the resist The solubility in the alkaline developer becomes higher, and the exposed portion is dissolved and removed by the alkaline developer to obtain a positive resist pattern.

2. Method for Forming Resist Pattern The resist pattern forming method of the present invention is a step of forming a photoresist film on a substrate using the radiation sensitive resin composition of the present invention or the radiation sensitive resin composition for immersion exposure (hereinafter referred to as “resist pattern forming method”). , “First step”), and a step of placing the immersion exposure liquid on the photoresist film and subjecting the photoresist film to immersion exposure via the immersion exposure liquid (hereinafter referred to as “second step”). And a step of developing a photoresist film subjected to immersion exposure to form a resist pattern (hereinafter referred to as “third step”).

The first step is a step of forming a photoresist film on the substrate using the radiation sensitive resin composition of the present invention or the radiation sensitive resin composition for immersion exposure. Examples of the method for applying the composition include spin coating, cast coating, roll coating, and the like. Examples of the substrate include a silicon wafer and a wafer coated with aluminum.
A specific example of the first step is a method of volatilizing the solvent in the coating film by applying the composition so that the obtained photoresist film has a predetermined thickness and then pre-baking (PB). . Thereby, a uniform photoresist film is formed.
The thickness of the photoresist film is not particularly limited, but is usually 0.05 to 0.40 μm.
The prebaking conditions are appropriately selected depending on the composition of the composition, but are preferably 30 ° C to 200 ° C, more preferably 50 ° C to 170 ° C. It is.

In the present invention, in order to maximize the potential of the composition, it is used, for example, as disclosed in Japanese Patent Publication No. 6-12452 (Japanese Patent Laid-Open No. 59-93448). An organic or inorganic antireflection film can also be formed on the substrate. In order to prevent the influence of basic impurities contained in the environmental atmosphere, a protective film can be provided on the photoresist film as disclosed in, for example, Japanese Patent Laid-Open No. 5-188598. Further, in order to prevent the acid generator and the like from flowing out of the photoresist film, an immersion protective film may be provided on the photoresist film as disclosed in, for example, JP-A-2005-352384. it can. These techniques can be used in combination.

The second step is a step in which an immersion exposure liquid is disposed on the photoresist film, and the photoresist film is subjected to immersion exposure via the immersion exposure liquid. In this step, the radiation illustrated below is usually used as exposure light through a photomask having a mask pattern for forming a desired pattern, and the surface of the photoresist film is irradiated with this radiation. . Thereby, the radiation passes through the opening of the photomask, further passes through the exposure lens, and reaches the photoresist film. The exposed portion in the photoresist film is removed by the third step.

As the immersion exposure liquid, pure water, a long chain or cyclic aliphatic compound, or the like can be used. Further, radiation is used as the exposure light for immersion exposure. The radiation can be appropriately selected according to the type of the acid generator in the composition. For example, visible light, ultraviolet light, far ultraviolet light, X-rays, charged particle beams, and the like can be used. Among these, far ultraviolet rays represented by ArF excimer laser (wavelength 193 nm) or KrF excimer laser (wavelength 248 nm) are preferable, and ArF excimer laser (wavelength 193 nm) is particularly preferable. In addition, exposure conditions, such as an exposure amount, can be suitably selected according to the composition of the composition, the type when an additive is contained, and the like.

After the second step, a step of baking the exposed film (hereinafter referred to as “PEB”) may be provided as necessary. By this step, the cross-linking reaction of the polymer contained in the exposed part can proceed smoothly.
The PEB heating conditions are appropriately selected depending on the composition of the composition, but are preferably 30 ° C. to 200 ° C., more preferably 50 ° C. to 170 ° C., from the viewpoint of facilitating the crosslinking reaction.

The third step is a step of developing a photoresist film subjected to immersion exposure to form a resist pattern. In this step, by using the developer, the unexposed portion in the second step is removed, and a pattern reflecting the pattern of the exposed portion, that is, the opening of the photomask, is left and formed.

As the developer, an alkaline aqueous solution obtained by dissolving an alkaline compound in water is usually used. Examples of the alkaline compound include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, ethyl Dimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [4.3.0] -5-nonene and the like. These may be used alone or in combination of two or more. Of the above compounds, tetramethylammonium hydroxide is preferred. The concentration of the alkaline compound is usually 10% by mass or less. If this concentration is too high, the exposed area may also be dissolved in the developer.

The developer may be a solution containing only the alkaline compound or a composition containing an organic solvent, a surfactant, and the like.
Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone, and 2,6-dimethylcyclohexanone; methanol, ethanol, n-propyl alcohol, isopropyl alcohol, alcohols such as n-butyl alcohol, tert-butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol, 1,4-hexanedimethylol; ethers such as tetrahydrofuran and dioxane; ethyl acetate, n-acetate Examples include esters such as butyl and isoamyl acetate; aromatic hydrocarbons such as toluene and xylene; phenol, acetonylacetone, and dimethylformamide. These organic solvents may be used alone or in combination of two or more.

When the developer contains an organic solvent, the content thereof is preferably 100 parts by volume or less with respect to 100 parts by volume of the alkaline aqueous solution. When there is too much content of this organic solvent, developability may fall and the image development residue of an unexposed part may increase.
After the third step, the pattern remaining on the substrate is usually washed with water and dried.

By providing the above steps, a line and space pattern with a small LWR can be formed while maintaining a wide exposure margin.

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. In the synthesis examples, examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified.

The GPC measurement method of the polymer obtained by the following synthesis example is as follows.
The weight average molecular weight (Mw) of the polymer is a GPC column (hereinafter referred to as model name) manufactured by Tosoh Corporation. Two "G2000HXL", one "G3000HXL" and one "G4000HXL" are connected to elute tetrahydrofuran. The measurement was performed by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under conditions of a flow rate of 1.0 mL / min and a column temperature of 40 ° C. as a solvent.

1. Polymers [A] and [C]
Synthesis Example 1 (Synthesis of polymer (A-1))
Compound (S1-1) 33.11 g (40 mol%), compound (S1-2) 12.22 g (10 mol%) and compound (S1-3) 54.67 g (50 mol%) shown below were converted into 2-butanone. A monomer solution was prepared by dissolving 8.02 g of 2,2′-azobisisobutyronitrile. On the other hand, 100 g of 2-butanone was put into a 1,000 mL three-necked flask and purged with nitrogen gas for 30 minutes.
After purging with nitrogen, 2-butanone in the three-necked flask was heated to 80 ° C. with stirring. Subsequently, the monomer solution prepared in advance was dropped over 3 hours using a dropping funnel. After completion of dropping, the mixture was further stirred at 80 ° C. for 3 hours.
After completion of the polymerization, the polymerization solution was cooled to 30 ° C. or less by water cooling. And this polymerization solution was thrown into 2,000 g of methanol, white powder was deposited, and this was separated by filtration after that. The white powder separated by filtration was washed twice as a slurry with 400 g of methanol and then filtered. Next, the white powder (copolymer) was dried at 50 ° C. for 17 hours (yield 80.1 g, yield 80%). When this copolymer was analyzed by ¹³ C-NMR, the content (mol%) of repeating units derived from the compound (S1-1), the compound (S1-2), and the compound (S1-3) was 41:10:49. This is designated as polymer (A-1). Mw of this polymer (A-1) was 7,300, and the fluorine atom content was 0%.

Synthesis Example 2 (Synthesis of polymer (A-2))
Compound (S1-1) 37.39 g (45 mol%), compound (S1-2) 12.26 g (10 mol%), compound (S1-4) 6.45 g (5 mol%) and compound (S1- 3) 43.90 g (40 mol%) was dissolved in 100 g of 2-butanone, and then 4.05 g of 2,2′-azobisisobutyronitrile was added to prepare a monomer solution. On the other hand, 100 g of 2-butanone was put into a 1,000 mL three-necked flask and purged with nitrogen gas for 30 minutes.
After purging with nitrogen, 2-butanone in the three-necked flask was heated to 80 ° C. with stirring. Subsequently, the monomer solution prepared in advance was dropped over 3 hours using a dropping funnel. After completion of dropping, the mixture was further stirred at 80 ° C. for 3 hours.
After completion of the polymerization, the polymerization solution was cooled to 30 ° C. or less by water cooling. And this polymerization solution was thrown into 2,000 g of methanol, white powder was deposited, and this was separated by filtration after that. The white powder separated by filtration was washed twice as a slurry with 400 g of methanol and then filtered. Then, the white powder (copolymer) was dried at 50 ° C. for 17 hours (yield 71 g, yield 71%). The copolymer was analyzed by ¹³ C-NMR. As a result, the content of repeating units derived from the compound (S1-1), the compound (S1-2), the compound (S1-4), and the compound (S1-3) ( mol%) was 45: 9: 5: 41, respectively. This is referred to as a polymer (A-2). Mw of this polymer (A-2) was 7,300, and the fluorine atom content was 1.4%.

Synthesis Example 3 (Synthesis of polymer (A-3))
Compound (S1-1) 32.49 g (40 mol%), Compound (S1-2) 11.99 g (10 mol%), Compound (S1-4) 12.61 g (10 mol%) and Compound (S1- 3) 42.91 g (40 mol%) was dissolved in 100 g of 2-butanone, and further 3.96 g of 2,2′-azobisisobutyronitrile was added to prepare a monomer solution. On the other hand, 100 g of 2-butanone was put into a 1,000 mL three-necked flask and purged with nitrogen gas for 30 minutes.
After purging with nitrogen, 2-butanone in the three-necked flask was heated to 80 ° C. with stirring. Subsequently, the monomer solution prepared in advance was dropped over 3 hours using a dropping funnel. After completion of dropping, the mixture was further stirred at 80 ° C. for 3 hours.
After completion of the polymerization, the polymerization solution was cooled to 30 ° C. or less by water cooling. And this polymerization solution was thrown into 2,000 g of methanol, white powder was deposited, and this was separated by filtration after that. The white powder separated by filtration was washed twice as a slurry with 400 g of methanol and then filtered. Subsequently, the white powder (copolymer) was dried at 50 ° C. for 17 hours (yield 70 g, yield 70%). The copolymer was analyzed by ¹³ C-NMR. As a result, the content of repeating units derived from the compound (S1-1), the compound (S1-2), the compound (S1-4), and the compound (S1-3) ( mol%) was 39: 11: 10: 40, respectively. This is designated as polymer (A-3). Mw of this polymer (A-3) was 7,100, and the fluorine atom content was 2.8%.

Synthesis Example 4 (Synthesis of polymer (A-4))
Compound (S1-1) 22.90 g (30 mol%), Compound (S1-2) 11.27 g (10 mol%), Compound (S1-4) 35.57 g (30 mol%) and Compound (S1- 3) 30.26 g (30 mol%) was dissolved in 100 g of 2-butanone, and 3.73 g of 2,2′-azobisisobutyronitrile was further added to prepare a monomer solution. On the other hand, 100 g of 2-butanone was put into a 1,000 mL three-necked flask and purged with nitrogen gas for 30 minutes.
After purging with nitrogen, 2-butanone in the three-necked flask was heated to 80 ° C. with stirring. Subsequently, the monomer solution prepared in advance was dropped over 3 hours using a dropping funnel. After completion of dropping, the mixture was further stirred at 80 ° C. for 3 hours.
After completion of the polymerization, the polymerization solution was cooled to 30 ° C. or less by water cooling. And this polymerization solution was thrown into 2,000 g of methanol, white powder was deposited, and this was separated by filtration after that. The white powder separated by filtration was washed twice as a slurry with 400 g of methanol and then filtered. Subsequently, the white powder (copolymer) was dried at 50 ° C. for 17 hours (yield 69 g, yield 69%). The copolymer was analyzed by ¹³ C-NMR. As a result, the content of repeating units derived from the compound (S1-1), the compound (S1-2), the compound (S1-4), and the compound (S1-3) ( mol%) was 30: 10: 29: 31, respectively. This is designated as polymer (A-4). Mw of this polymer (A-4) was 6,800, and the fluorine atom content was 7.8%.

Synthesis Example 5 (Synthesis of polymer (A-5))
Compound (S1-1) 31.27 g (40 mol%), compound (S1-2) 11.54 g (10 mol%), compound (S1-5) 15.87 g (10 mol%) and compound (S1- 3) 41.31 g (40 mol%) was dissolved in 100 g of 2-butanone, and 3.82 g of 2,2′-azobisisobutyronitrile was further added to prepare a monomer solution. On the other hand, 100 g of 2-butanone was put into a 1,000 mL three-necked flask and purged with nitrogen gas for 30 minutes.
After purging with nitrogen, 2-butanone in the three-necked flask was heated to 80 ° C. with stirring. Subsequently, the monomer solution prepared in advance was dropped over 3 hours using a dropping funnel. After completion of dropping, the mixture was further stirred at 80 ° C. for 3 hours.
After completion of the polymerization, the polymerization solution was cooled to 30 ° C. or less by water cooling. And this polymerization solution was thrown into 2,000 g of methanol, white powder was deposited, and this was separated by filtration after that. The white powder separated by filtration was washed twice as a slurry with 400 g of methanol and then filtered. Subsequently, the white powder (copolymer) was dried at 50 ° C. for 17 hours (yield 81 g, yield 81%). The copolymer was analyzed by ¹³ C-NMR. As a result, the content of repeating units derived from the compound (S1-1), the compound (S1-2), the compound (S1-5), and the compound (S1-3) ( mol%) was 39: 10: 10: 41, respectively. This is designated as polymer (A-5). This polymer (A-5) had an Mw of 7,800 and a fluorine atom content of 2.6%.

Synthesis Example 6 (Synthesis of polymer (C-1))
Compound (S3-1) 14.5 g (20 mol%) and compound (S3-2) 84.6 g (80 mol%) shown below are dissolved in 2-butanone 150 g, and 2,2′-azobis is further dissolved. A monomer solution was prepared by adding 3.47 g of isobutyronitrile. Meanwhile, the inside of the 500 mL three-necked flask was purged with nitrogen gas for 30 minutes.
After purging with nitrogen, the inside of the three-necked flask was heated to 80 ° C. while stirring. Subsequently, the monomer solution prepared in advance was dropped over 3 hours using a dropping funnel. After completion of dropping, the mixture was further stirred at 80 ° C. for 3 hours.
After completion of the polymerization, the polymerization solution was cooled to 30 ° C. or less by water cooling. And this polymerization solution was thrown into 600 g of methanol, white powder was deposited, and this was separated by filtration after that. The white powder separated by filtration was washed twice with 300 g of methanol as a slurry, and then filtered. Next, the white powder was dried at 50 ° C. for 17 hours to obtain a colorless solid copolymer (yield 72 g, yield 72%). The copolymer was analyzed by ¹³ C-NMR, whereby the content (mol%) of repeating units derived from the compound (S3-1) and the compound (S3-2) was 21:79, respectively. This is referred to as a polymer (C-1). This polymer (C-1) had an Mw of 6,400 and a fluorine atom content of 12.8%.

2. Production and Evaluation of Radiation Sensitive Resin Composition Other raw material components for preparing the composition are shown below.
2-1. Acid generator [B]
(1) B-1
4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate (2) B-2
Triphenylsulfonium = tricyclo [3.3.1.1 ^3,7 ] decanyl difluoromethanesulfonate

2-2. Acid diffusion inhibitor [D]
(1) D-1
tert-Butyl-4-hydroxy-1-piperidinecarboxylate (2) D-2
2,6-Diisopropylaniline

2-3. Solvent [F]
(1) F-1
Propylene glycol monomethyl ether acetate (2) F-2
Cyclohexanone

Example 1
100 parts of polymer (A-2), 12 parts of acid generator (B-1), 5 parts of polymer (C-1), 0.8 part of acid diffusion inhibitor, solvent (F-1) 1,980 parts and 848 parts of solvent (F-2) were mixed to obtain a uniform solution. Then, the radiation sensitive resin composition (composition solution) was manufactured by filtering using a membrane filter with a pore diameter of 200 nm (see Table 1).

Examples 2 to 6 and Comparative Example 1
A radiation-sensitive resin composition (composition solution) was produced in the same manner as in Example 1 except that the raw material components were used according to the formulation described in Table 1 (see Table 1).

Using each of the radiation sensitive resin compositions, a line and space pattern was formed on the antireflection film disposed on the silicon wafer in the following manner, and LWR was evaluated. The results are also shown in Table 1.
(1) Formation of resist pattern On the surface of a 12-inch silicon wafer, a composition for forming a lower antireflection film (trade name “ARC66”, manufactured by Nissan Chemical Co., Ltd.) Spin-coated using Electron). Next, PB (205 ° C., 60 seconds) was performed to form an antireflection layer having a thickness of 105 nm.

Then, the radiation sensitive resin composition was spin-coated using a semiconductor manufacturing apparatus (model name “CLEAN TRACK ACT12”, manufactured by Tokyo Electron Ltd.). Then, PB (110 ° C., 60 seconds) and cooling (23 ° C., 30 seconds) were performed to form a 100 nm-thick photoresist layer.

Next, using an ArF immersion exposure apparatus (trade name “S610C”, manufactured by NIKON Corporation), exposure is performed through a mask having a target size of 48 nm line / 96 nm pitch under optical conditions of NA: 1.30 and Crosspore. did. Thereafter, PEB (95 ° C., 60 seconds) was performed and cooled (23 ° C., 30 seconds) on a hot plate of a semiconductor manufacturing apparatus (model name “Lithius Pro-i”, manufactured by Tokyo Electron Ltd.). Next, paddle development (10 seconds) was performed using a 2.38% tetramethylammonium hydroxide aqueous solution as a developer with a GP nozzle of the developing cup, and rinsed with ultrapure water. Thereafter, the silicon wafer for evaluation on which a resist pattern (line and space pattern) was formed was obtained by spin-drying by shaking off at 2000 rpm for 15 seconds. At this time, the exposure amount for forming a pattern of 48 nm line / 96 nm pitch in the mask size with a target size of 48 nm line / 96 nm pitch was determined as the optimum exposure amount.

(2) Measurement of LWR Using a scanning electron microscope, a 48 nm line / 96 nm pitch pattern resolved at the optimum exposure dose was observed from above, and the line width was measured at 10 arbitrary points. The 3σ (variation) of the measured value was defined as LWR (unit: nm).

As is clear from Table 1, Comparative Example 1 is an example using a radiation-sensitive resin composition containing a polymer that does not contain a repeating unit represented by the general formula (1) according to the present invention. Is as high as 4.7, which is not preferable. On the other hand, the radiation sensitive resin compositions of Examples 1 to 6 were excellent with an LWR of less than 4.

When the radiation-sensitive resin composition of the present invention is used, a chemically amplified resist capable of maintaining a good line width roughness (LWR) while maintaining a wide exposure margin can be obtained. In particular, for the formation of chemically amplified resists useful for microfabrication using X-rays such as far-ultraviolet rays, synchrotron radiation, and other charged particle beams such as electron beams, such as KrF excimer laser and ArF excimer laser. Is preferred. And it is very useful for the manufacture of a semiconductor device which is expected to be further miniaturized in the future.

Claims

[A] A polymer containing a repeating unit represented by the following general formula (1) and having an acid-dissociable group, [B] a radiation-sensitive acid generator, and [C] a polymer containing a fluorine atom And the content rate of the fluorine atom contained in the said polymer [A] is less than the content rate of the fluorine atom contained in the said polymer [C], The radiation sensitive resin composition characterized by the above-mentioned.

(Wherein R 1 is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, and R 2 is a hydrocarbon group having 1 to 20 carbon atoms or a fluorinated carbon atom having 1 to 20 carbon atoms) A hydrogen group, and Q 1 is a divalent linking group.)
The content of the repeating unit represented by the general formula (1) is 5 to 50 mol%, when the total amount of the repeating units constituting the polymer [A] is 100 mol%. Radiation sensitive resin composition.
The radiation sensitive resin composition according to claim 1 or 2, wherein the polymer [A] further contains a repeating unit represented by the following general formula (2).

(Wherein R 3 is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, and R 4 is independently a linear or branched alkyl group having 1 to 4 carbon atoms. Or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a divalent formed by bonding two R 4 to each other and having 4 to 20 carbon atoms. (It may be an alicyclic hydrocarbon group or a derivative group thereof.)
The polymer [A] further contains at least one repeating unit selected from the group consisting of repeating units represented by the following general formulas (3-1) to (3-6): The radiation sensitive resin composition in any one.

(Wherein R 5 is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, R 6 is a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, R 7 is a single bond or a methylene group, R 8 is a hydrogen atom or a methoxy group, R 9 is an oxygen atom or a methylene group, p is 1, 2 or 3, and m is 0 or 1)
The polymer [C] contains at least one repeating unit selected from the group consisting of repeating units represented by the following general formulas (c1-1) to (c1-3): The radiation sensitive resin composition described in 1.

(Wherein R 21 represents a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, R 22 represents a fluorinated hydrocarbon group having 1 to 30 carbon atoms, and R 23 represents Independently a hydrogen atom, a fluorine atom or a fluorinated hydrocarbon group having 1 to 30 carbon atoms, R 24 is a hydrogen atom, an acid dissociable group or an alkali dissociable group, and Q 3 is (g + 1) Q 4 is a divalent linking group and g is 1, 2 or 3. provided that in formulas (c1-2) and (c1-3), all R 23 Is not a hydrogen atom.)
[A] For immersion exposure, comprising a polymer having a repeating unit represented by the following general formula (1) and having an acid-dissociable group, and [B] a radiation-sensitive acid generator Radiation sensitive resin composition.

(Wherein R 1 is a hydrogen atom, a trifluoromethyl group or an alkyl group having 1 to 4 carbon atoms, and R 2 is a hydrocarbon group having 1 to 20 carbon atoms or a fluorinated carbon atom having 1 to 20 carbon atoms) A hydrogen group, and Q 1 is a divalent linking group.)
A step of forming a photoresist film on a substrate using the radiation-sensitive resin composition according to claim 1;
Placing an immersion exposure liquid on the photoresist film, and immersion exposing the photoresist film through the immersion exposure liquid;
Developing the photoresist film that has been subjected to immersion exposure to form a resist pattern; and
A resist pattern forming method comprising: