TW201640562A - Substrate having thin film layer for pattern-formation mask, and method for manufacturing patterned substrate - Google Patents

Abstract

To provide a substrate having a thin film layer for a pattern-formation mask, with which a relief pattern exhibiting excellent processing precision can be formed on the surface of a substrate by dry etching, and a method for manufacturing a patterned substrate by using the substrate having a thin film layer for a pattern-formation mask. A substrate, which has a thin film layer for a pattern-formation mask, comprising a substrate formed from silicon or a silicon compound, and a thin film layer which is provided to the surface of the substrate, which is patterned by etching using plasma from a mixed gas of oxygen and chlorine, and which is to be used as a mask for pattern formation. If the value for the thickness of the thin film layer is plotted on a vertical axis, and the value for the chromium content ratio in the film thickness layer is plotted on a horizontal axis, and the values are varied, the use of a thin film having a thickness of at most 10nm and comprising chromium oxide having a chromium content ratio of 40-50 at% resulted in excellent sidewall angles in LER after quartz dry etching, and maintained resistance as an etching mask, and is therefore effective for the present invention.

Description

Substrate with patterned film layer for mask and method for manufacturing patterned substrate

The present invention relates to a substrate for patterning a mask layer for forming a mask, and a method for producing a patterned substrate, wherein the substrate for patterning the mask layer is a patterned surface of a substrate having a concave-convex pattern formed on the surface thereof. The film layer for the mask used as the mask pattern at the time of pattern formation is provided.

The microfabrication technology associated with the high integration of large-scale integrated circuits has become an extremely important technology in recent years. Among semiconductor microfabrication technologies, in recent years, from the viewpoint of production cost, ultraviolet (Ultra Violet, UV) nanoimprint lithography which does not require a device cost has been attracting attention as compared with the conventional photolithography. In the conventional photolithography, a photomask including a light-shielding fine pattern such as a metal thin film is provided on a translucent glass substrate (Patent Document 1 and the like). On the other hand, in the UV nanoimprint lithography, a nanoimprint template in which a fine concavo-convex pattern is formed on the surface of a substrate that transmits UV light (ultraviolet light) is used (Patent Document 2, Patent Document 3, etc.).

The nanoimprint stencil used in the manufacture of the semiconductor device can similarly use a mask blanks having a hard mask layer on a quartz substrate used in the fabrication of the reticle. Specifically, it can be produced by forming a resist pattern on the hard mask layer of the blank mask, and then using the resist pattern as a mask to etch the hard mask layer to form a mask pattern. The quartz is then etched using the mask pattern.

With the demand for high integration of semiconductor circuits, the size of the pattern of the nanoimprint template needs to be further refined. As the size of the pattern is miniaturized, the improvement of the processing accuracy in the etching of the quartz substrate becomes necessary. .

In addition, it is not limited to the manufacture of a semiconductor device, and in an optical component in which an optical function is added by a fine pattern such as a grating, a pattern size and accuracy smaller than the wavelength of the target light are required, and thus optical is required. It is also required to improve the processing accuracy during etching in the imprinting template for part production or in the fabrication of the optical component itself.

From the viewpoint of the etching ratio, a hard mask for etching a quartz substrate is mainly a chromium compound containing chromium, and Patent Documents 1 to 3 disclose a blank mask having a chromium compound layer on a quartz substrate. [Prior Art Document] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. 2008-207163.

[Problems to be solved by the invention]

As apparent from the study by the inventors of the present invention, the processing precision in the etching of quartz greatly depends on the film quality of the hard mask layer. Specifically, the processing precision of the finished pattern is greatly different depending on the composition thereof.

Patent Document 1 discloses a blank mask having a laminated film-like hard mask layer having a chrome metal layer and a chromium compound layer. Patent Document 1 is intended for the production of a photomask. Therefore, it is premised that the hard mask layer has light-shielding properties, and the thickness of the entire hard mask layer must be made thicker than in the case where the light-shielding property is not premised. In order to ensure the light shielding property, it is considered that the thickness of the entire hard mask layer must be 30 nm or more. Further, in Patent Document 1, since a mask is formed by patterning a hard mask layer, the case of etching quartz is not described.

Patent Document 3 also mainly aims at the production of a photomask, and therefore it is premised on the fact that the hard mask layer has light shielding properties. Patent Document 3 discloses a hard mask layer having a laminated structure of a layer containing chromium as a main component and containing 60 at% or more of oxygen and a layer containing ruthenium, osmium or zirconium as a main component. A hard mask layer having a layer containing ruthenium, osmium or zirconium as a main component has a problem of high cost. In addition, it has been clarified by the inventors of the present invention that when the layer containing chromium as a main component contains 60 at% or more of oxygen, the mask for dry etching of quartz is not sufficiently etch-resistant. .

Patent Document 2 discloses a blank mask having a hard mask layer containing CrOxNyCz (where x > 0) as a chromium compound. However, Patent Document 2 does not show a preferable composition range in which high processing accuracy can be obtained when the hard mask layer containing CrOxNyCz (where x>0) is dry-etched.

The present invention has been made in view of the above circumstances, and it is an object of the invention to provide a substrate for forming a film layer for a mask which can be patterned by a dry etching to form a concave-convex pattern on a surface of a substrate with high processing precision. Further, it is an object of the invention to provide a method of producing a patterned substrate using a substrate having a film layer for patterning a mask. [Means for solving the problem]

The substrate of the film layer for patterning the mask of the present invention comprises: a substrate comprising a ruthenium or a lanthanide compound; and a film layer disposed on the surface of the substrate and etched by a plasma using a mixed gas of oxygen and chlorine Further, it is patterned to be used as a mask for pattern formation; and the thin film layer contains a chromium oxide having a chromium content of 40 at% or more and 50 at% or less, and has a thickness of 10 nm or less.

The method for producing a patterned substrate of the present invention is a method of preparing a substrate with a pattern forming a film layer for a mask, the substrate of the patterned film layer for masking comprising a substrate comprising a ruthenium or a lanthanide compound and a film layer. The film layer is provided on the surface of the substrate, and includes a chromium oxide having a chromium content of 40 atom% or more and 50 atom% or less and having a thickness of 10 nm or less; forming a mask layer for patterning on the film layer; The mask layer is etched by using a plasma of a mixed gas of oxygen and chlorine to pattern the thin film layer; the patterned thin film layer is used as a mask, and is etched by using a plasma containing a fluorine-based gas. Thereby, the surface of the substrate is patterned.

The method for producing a patterned substrate of the present invention is suitable for the case of including a portion having a pattern line width of 50 nm or less in patterning, and more preferably including a portion having a pattern line width of 30 nm or less.

In the method for producing a patterned substrate of the present invention, the ratio of oxygen to chlorine in the mixed gas of oxygen and chlorine is preferably 0.05 to 0.40. Here, the ratio of oxygen to chlorine is a flow ratio (oxygen/chlorine) of oxygen and chlorine introduced into the etching apparatus.

Moreover, it is preferable that the fluorine-containing gas content rate in the plasma containing a fluorine-based gas is 50% or less. In addition, the fluorine-based gas is a gas containing at least fluorine as a constituent element such as a fluorocarbon gas or a sulfur hexafluoride gas, and the gas contained in the plasma may be any fluorine-based gas or a plurality of fluorine. The type of gas.

In the formation of the mask layer for patterning, a method of applying a resist film on the film layer and forming a concave-convex pattern on the resist film by an imprint method may be employed.

The patterned substrate can, for example, be a nanoimprint template or an optical element. The nanoimprint template includes: a master template; or a secondary template produced by using a master template and transferring a concave-convex pattern by an imprint method. [Effects of the Invention]

The substrate of the film layer for patterning the mask of the present invention includes a thickness of 10 nm or less including a chromium oxide having a chromium content of 40 at% or more and 50 at% or less on a substrate containing a ruthenium or a ruthenium compound. Since the film layer is patterned by etching using a plasma of a mixed gas of oxygen and chlorine, a mask pattern having a very high processing precision can be formed, and as a result, high processing can be formed on the surface of the substrate. Accurate bump pattern.

Further, in the method for producing a patterned substrate of the present invention, the film layer of the substrate layer for patterning the mask layer of the present invention is patterned by etching treatment using a plasma of a mixed gas of oxygen and chlorine. Therefore, a mask pattern having high processing accuracy can be obtained, and then the substrate can be etched by using the patterned film layer as a mask to obtain a patterned substrate having a concave-convex pattern having high processing precision.

Hereinafter, embodiments of the present invention will be described using the drawings, but the present invention is not limited thereto. Further, in order to facilitate visual recognition, the scale of each component in the drawings and the like may be appropriately changed from the actual person.

<Base of the film layer for patterning the mask of the first embodiment> Fig. 1 is a cross-sectional view of the substrate 1 of the film layer for patterning the mask according to the first embodiment of the present invention. The substrate 1 of the patterned film layer for masking of the present embodiment includes a substrate 40 containing a ruthenium or a lanthanide compound, and a film layer 50 disposed on the surface of the substrate 40 by using oxygen and The plasma of the mixed gas of chlorine is patterned by etching to be used as a mask for pattern formation, and the thin film layer 50 contains chromium oxide having a chromium content of 40 at% or more and 50 at% or less and has 10 Thickness below nm.

The base 40 is a base having a patterned surface on which a fine uneven pattern is formed on the surface, and in FIG. 1, the base 40 is a flat substrate. Examples of the oxime compound constituting the substrate 40 include SiO ₂ and SiON. In terms of the etching ratio of the thin film layer 50 containing chromium oxide, it is particularly preferable to include a synthetic quartz having SiO ₂ as a main component. Here, the main component means a component which accounts for 90% or more of all components.

The film layer 50 contains chromium oxide. When the chromium content in the entire layer is 40 atom% or more and 50 atom% or less, the chromium content may be less than 40 atom% or more than 50 atom% depending on the position in the depth direction. With respect to the chromium content of the entire layer, X-ray photoelectron spectroscopy is performed while performing Ar etching from the surface of the layer in the depth direction, and the depth dependence of the element content rate of each element is measured, and the element content rate is in the depth direction. The ratio of the value obtained by the integration is used as the film content ratio (atomic %) of each element to determine the chromium content (atomic %) as the entire film.

The film layer 50 is not necessarily a light-shielding layer, and the film layer 50 preferably has a thickness of 10 nm or less. The thickness is preferably 0.5 nm or more, more preferably 2.5 nm or more. Further, the thickness of the film layer here is a thickness measured by observing the processed cross section by a transmission electron microscope by processing the substrate with a focused ion beam.

The base 1 of the film layer for patterning the mask of the present embodiment can be used, for example, for producing a master template for nanoimprinting, and when applied to a photoimprint method, the substrate 40 must have transparency for light used for imprinting. For example, in the case of an imprint method including a step of hardening a resist by using UV light, it is preferably at least transparent to UV light.

The substrate of the base layer of the patterned film layer for masking of the present invention is not limited to a flat substrate, and is not particularly limited as long as it contains a ruthenium or a ruthenium compound having a surface on which a concave-convex pattern can be formed. The surface on which the uneven pattern can be formed is not limited to a flat surface, and may be a curved surface. For example, an optical member such as a concave lens or a convex lens may be used as a base. Further, in the case of producing an optical member, a substrate containing a material transparent to visible light is generally used.

<Base of the film layer for pattern forming mask of the second embodiment> Fig. 2 is a cross-sectional view of the substrate 2 of the film layer for patterning the mask of the second embodiment. In the present embodiment, the base 10 having a counterbore 11 on one side is included. The base 10 and the region of the other surface corresponding to the counterbore portion 11 include the pedestal portion 12.

Such a substrate 10 is particularly suitable for transfer of concave and convex patterns by nanoimprinting, and the substrate is particularly preferably composed of quartz. When the pedestal portion 12 provided on the surface of the base 10 is provided with a embossed pattern template, the region where the template is in contact with the transfer medium such as a wafer can be limited to the surface of the pedestal portion 12 when used in the device manufacturing step. Therefore, there is an advantage that it is possible to avoid contact with a structure existing outside the pattern forming region of the template. The height (step) of the pedestal portion 12 is preferably from 1 μm to 1000 μm, more preferably from 10 μm to 500 μm, still more preferably from 20 μm to 100 μm.

The substrate 10 can be used with a circular wafer of 2 inches to 8 inches; or the size of a reticle used in semiconductor lithography at 65 mm x 65 mm, 5 inches x 5 inches, 6 A round counterbore is provided in the center of the back of the square body of the inch x 6 inch, or 9 inch x 9 inch. The shape of the counterbore portion 11 is determined in consideration of the permeability of the gas and the bending (flexural rigidity) of the substrate at the portion which is thinned by the countersink processing.

Further, the configuration and effect of the film layer 20 of the base 2 of the film layer for patterning the mask of the present embodiment and the film layer 50 of the base 1 of the film layer for patterning the mask of the first embodiment are different. the same.

A method of forming the thin film layer 20 on the substrate 10, the thin film layer 20, and the thin film layer 50 in the substrate 2 with the film layer for patterning the mask, and the substrate 2 having the patterned film layer for the mask will be described. The film formation method of the film layer 20 and the film layer 50 is not particularly limited, and for example, vapor phase film formation can be used, and more specifically, sputtering, chemical vapor deposition, molecular beam epitaxy, or ion beam sputtering can be used. Plating or the like is formed. Particularly preferred is formed by sputtering.

More specifically, it is preferable to use Cr by a sputtering method, and to use a mixed gas of Ar gas and oxygen, or to use only Ar gas. In the case of using O ₂ gas, the O ₂ gas flow rate ratio at the time of sputtering is preferably one-twentieth or less with respect to Ar. It can be used for direct current (DC) sputtering or high frequency (RF) sputtering. When using Ar gas alone for sputtering, any one of them can be used for O ₂ gas and Ar gas. In the case of a mixed gas, RF sputtering is preferably used.

The amount of oxygen in the gas is appropriately determined in order to control the chromium content in the film obtained by sputtering. In order to control the oxygen content rate in the depth direction, oxygen may be introduced only at the start of film formation or in a very short time in the middle of film formation.

The thickness of the thin film layer 20 and the thin film layer 50 is 10 nm or less, and can be appropriately selected in consideration of the target processing depth of the concavo-convex pattern concave portion on the finally obtained substrate, the etching selectivity ratio of the resist, and the transmittance. The lower limit of the thickness is about 0.5 nm necessary for forming a film uniformly on the surface of the substrate, and the thickness is 1 nm or more, and more preferably 2.5 nm or more.

As a mask pattern formed by etching the thin film layer 20 and the thin film layer 50, the narrower the width of the concave portion of the pattern, the lower the etching rate of the thin film layer at the bottom of the concave portion due to the micro loading effect. By setting the thickness of the thin film layer to 10 nm or less, the etching time at the time of forming the mask pattern can be suppressed, and as a result, the discontinuity due to the disappearance of the resist pattern can be suppressed before the thin film layer is etched. Line) the generation of defects.

In addition, when the chromium content of the entire film as the thin film layer is 40 atom% or more, the resistance of the mask when the substrate is etched is sufficient, and the cross-sectional shape of the convex portion is close to a rectangular pattern. Further, by setting the chromium content to 50% or less, the line edge roughness (LER) can be lowered, and the side wall angle can be made closer to 90°. Further, a standard which can be called a mask pattern with high processing accuracy is that the side wall angle is 85° or more, and the 3σ value of the LER is one tenth or less of the set line width.

When the uneven pattern is to be accurately formed on the surface of the base 10 and the base 40, the processing accuracy of the mask pattern formed by etching the thin film layer 20 and the thin film layer 50 is required to be sufficiently high. By including a thin film layer having a chromium content of 40 atom% or more, 50 atom% or less, and 10 nm or less in the entire layer, a mask pattern having high processing precision can be obtained, and as a result, 50 nm can be formed on the processed surface of the substrate. Hereinafter, a concave-convex pattern of a pattern line width of 30 nm or less and further less than 30 nm.

Next, a method of producing the patterned substrate of the present invention will be described. The method for producing a patterned substrate of the present invention is a method for producing a patterned substrate from the substrate of the film layer for masking.

<Method for Producing Patterned Substrate of First Embodiment> FIGS. 3(a) to 3(f) are views showing a procedure of a method of manufacturing a patterned substrate according to the first embodiment. Here, a procedure for producing a master template for a nanoimprint as a patterned substrate using the substrate 1 of the patterned film layer for a mask of the first embodiment will be described.

In the method of manufacturing the patterned substrate of the first embodiment, the substrate 1 for patterning the mask layer of the first embodiment is prepared (step a), and the mask layer 65 for patterning is formed on the film layer 50 (step Bc), by using the mask layer 65 and etching using a plasma of a mixed gas of oxygen and chlorine, patterning the thin film layer 50 to form a mask pattern 55 (step d), by masking the pattern As a mask, the surface of the substrate 40 is etched by a plasma containing fluorine, and a concave-convex pattern is formed on the surface of the substrate 40 (step e), and the patterned substrate 40A is obtained by removing the mask pattern 55 (step f) ).

In the step a of the present embodiment, for example, a film layer for patterning a mask formed by forming a film layer 50 on a substrate 40 including a quartz substrate having a thickness of 0.25 inches (0.635 cm) and having a thickness of 0.25 inches (0.635 cm) is prepared. Base 1.

In the step bc of forming the mask layer 65, for example, a resist liquid containing a polyhydroxy styrene (PHS)-based chemical amplification resist or the like as a main component is formed by spin coating. The resist layer 60 is then irradiated with an electron beam while scanning the substrate 1 on the XY stage, and the range of 25 mm × 31 mm square of the resist layer 60 is patterned. Then, the resist layer is subjected to development processing to remove the exposed portion to form a resist pattern (hereinafter referred to as a resist pattern 65) as the mask layer 65.

In the step d of patterning the thin film layer 50 to form the mask pattern 55, for example, reactive ion etching (RIE) is used as the etching. The etching conditions for the RIE are selected such that the etching selectivity of the thin film layer with respect to the resist layer becomes large. The reason for this is that if the selection ratio is small, the resist pattern partially disappears to cause a discontinuity (broken line) defect. Here, it is defined as the selection ratio = the etching rate of the thin film layer / the etching speed of the resist layer.

In the step d, in order to perform anisotropic etching, it is preferable to perform etching for applying bias power to the etching apparatus. By imparting anisotropic etching by applying bias electric power, an increase in critical dimension (CD) can be suppressed. However, if the bias power is too large, the speed at which the resist pattern disappears is fast, and therefore the bias input power is usually preferably 0.01 W/inch ² to 0.3 W/inch ² (15.5 W/m ² to 465 W/m). ² ) (indicated by the value obtained by dividing the input power by the area of the substrate). Further, details of the etching apparatus will be described later.

In the etching of this step d, a mixed gas of oxygen and chlorine is used, and etching is performed using the plasma of the mixed gas. Since the thin film layer is a chromium oxide, the chromium oxide can be etched by using a mixed gas of chlorine (Cl ₂ ) and oxygen (O ₂ ) to form chromium oxychloride (CrO ₂ Cl ₂ ).

In the etching step e of the substrate 40 in which the mask pattern 55 is used as the mask, as in the etching of the thin film layer, RIE is preferably used, and inductively coupled plasma (ICP)-RIE and capacitance are particularly preferable. Capacitively coupled plasma (CCP)-RIE or Electron Cyclotron Resonance (ECR)-RIE. The etching gas for the substrate 40 containing quartz is a mixed gas using a fluorine-based gas (CHF ₃ , CF ₄ , SF ₆ , and/or C ₄ F ₈ ) and a rare gas such as Ar, He, or Xe. The ratio of the fluorine-based gas to the rare gas is preferably 1 or less. Here, the ratio of the fluorine-based gas to the rare gas is a flow ratio (fluorine-based gas/rare gas) of the fluorine-based gas and the rare gas introduced into the etching apparatus.

In the step f of removing the mask pattern 55, the mask pattern 55 can be removed by, for example, etching using a mixed gas of chlorine and oxygen.

By the above steps, for example, a patterned substrate having a concave-convex pattern of a groove pattern having a groove shape of 28 nm, a pitch of 56 nm, and a depth of 60 nm can be formed in the central portion of the base 40 including the quartz substrate. 40A.

The patterned substrate 40A can be used as a master template in nanoimprinting. Further, the surface of the patterned substrate 40A can be subjected to a mold release treatment by a dip coating method, and it can be used in the method for producing a patterned substrate according to the second embodiment described below.

<Method for Producing Patterned Substrate of Second Embodiment> FIGS. 4(a) to 4(e) are views showing a procedure of a method of manufacturing a patterned substrate according to the second embodiment. Here, a description will be given of a step of using the base 2 of the patterned film layer for masking of the second embodiment and using the method of manufacturing the patterned substrate of the first embodiment. The base 40A is used as a main template (hereinafter referred to as a main template 40A), and a concave-convex pattern is transferred by a nanoimprint method to prepare a secondary template as a patterned substrate.

In the method of manufacturing the patterned substrate of the second embodiment, the substrate 2 for patterning the mask layer of the second embodiment is prepared (step a), and the mask layer 35 for patterning is formed on the film layer 20 (step b), by using the mask layer 35 and etching with a plasma of a mixed gas of oxygen and chlorine, patterning the thin film layer 20 to form a mask pattern 25 (step c), by masking the pattern As a mask, the surface of the substrate 10 is etched by a plasma containing fluorine to form a concave-convex pattern on the surface of the substrate 10 (step d), and the patterned substrate 10A is obtained by removing the mask pattern 25 (step e).

In the step a of the present embodiment, for example, it is prepared to be 6 inches × 6 inches, the thickness of the portion which is not the counterbore portion 11 is 6.35 mm, the diameter of the circular counterbore portion is 63 mm, and the countersunk hole portion is prepared. The remaining substrate having a thickness of 1.1 mm and having a thin film layer 20 formed on the substrate 10 containing quartz has a substrate 2 patterned to form a film layer for a mask.

In the step b of forming the mask layer 35, the nanoimprint method using the master template 40A obtained by the method for producing a patterned substrate of the first embodiment is used. FIGS. 5(b ₁ ) to 5( b ₅ ) are diagrams schematically showing a procedure of forming a resist pattern (hereinafter referred to as a resist pattern 35) as the mask layer 35 by a nanoimprint method. Forming method using a nanoimprint resist pattern 35 includes, in order: a step b _1, the formation of the coating solution 30 on the resist film layer 20 on the substrate 10; pressing step b _2, the main template 40A The surface of the substrate 2 with the film layer for patterning the mask is brought into contact with and pressed against the surface of the substrate 2 coated with the resist liquid 30; and the curing step b ₃ - b _{4 is} performed to cure the resist film 32 having the uneven pattern as a resist The mold pattern 35; and the demolding step b ₅ , demolding the master template 40A from the resist pattern 35. Each step will be described below.

[Resistant Liquid Coating Step b ₁ ] First, the resist liquid 30 to be used will be described. The resist liquid 30 is not particularly limited, and for example, a material prepared by adding a photopolymerization initiator (about 2% by mass) or a fluorine monomer (0.1% by mass to 1% by mass) to the polymerizable compound can be used. Further, an antioxidant (about 1% by mass) may be added as needed. The resist liquid obtained by the above sequence can be hardened by using UV light having a wavelength of 360 nm. In the case of poor solubility, it is preferred to add a small amount of acetone or ethyl acetate to dissolve it, and then the solvent is distilled and removed. The polymerizable compound may, for example, be benzyl acrylate (Viscoat #160: manufactured by Osaka Organic Chemical Co., Ltd.) or ethyl carbitol acrylate (Viscoat #190: Osaka) Polypropylene glycol diacrylate (Aronix M-220: manufactured by Toagosei Co., Ltd.), trimethylolpropane PO modified triacrylate (Aronix) M-310: manufactured by Toagosei Co., Ltd., and the like, and the compound A or the like represented by the following structural formula (1) is exemplified. Further, the polymerization initiator may be exemplified by 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl A phenylalkyl ketone-based photopolymerization initiator such as 1-butanone (IRGACURE 379: manufactured by Toyotsu Chemiplas Co., Ltd.). In addition, the fluorine monomer may, for example, be a compound B represented by the following structural formula (2). Here, the viscosity of the resist is preferably 8 cP to 20 cP, and the surface energy of the resist layer after the application of the resist liquid is preferably 25 mN/m to 35 mN/m.

[Chemical 1] [Chemical 2]

The resist coating method of applying the resist liquid may be a method of disposing a predetermined amount of droplets at a predetermined position on a substrate or a master template by using an inkjet method, a dispensing method, or the like. However, a method in which a resist can be applied with a uniform film thickness such as a spin coating method or a dip coating method can also be used. When droplets are placed on the substrate, the ink jet printer or dispenser can be used separately depending on the amount of droplets required. For example, an inkjet printer is used in the case where the amount of droplets is less than 100 nl (nanoliter), and a method such as a dispenser is used in the case of 100 nl or more.

Examples of the ink jet head that ejects liquid droplets from the nozzle include a piezoelectric method, a thermal method, and an electrostatic method. Among these methods, a piezoelectric method in which the amount of droplets (the amount of droplets arranged per droplet) or the ejection velocity can be adjusted is preferable. The droplet amount or the ejection speed is set and adjusted in advance before the droplets are placed on the substrate. For example, the amount of liquid droplets is preferably adjusted such that the position on the substrate corresponding to the region where the spatial volume of the concave-convex pattern of the main template is large is increased, and corresponds to a region having a small spatial volume of the concave-convex pattern of the main template. The position on the substrate is reduced. This adjustment is appropriately controlled in accordance with the amount of droplet discharge (the amount of droplets ejected per droplet). Specifically, when the amount of liquid droplets is set to 5 pl (picoliter), the liquid is sprayed five times at the same position using an ink jet head having a droplet discharge amount of 1 pl. Drop amount. The amount of liquid droplets is obtained by, for example, measuring a three-dimensional shape of droplets previously ejected onto a substrate under the same conditions by a confocal microscope or the like, and calculating the volume according to the shape. After the amount of droplets is adjusted in the manner described above, droplets are placed on the substrate in accordance with a predetermined droplet arrangement pattern. The droplet arrangement pattern is composed of two-dimensional coordinate information including a group of lattice points corresponding to the droplet arrangement on the substrate.

On the other hand, when a spin coating method or a dip coating method is used, the resist is diluted with a solvent so as to have a predetermined thickness, and in the case of a spin coating method, by dip coating by controlling the number of revolutions In the case of the cloth method, it is only necessary to form a uniform coating film on the substrate by controlling the pulling speed.

<Extrusion Step b ₂ > Before the main template 40A is brought into contact with the resist coated surface on the surface of the thin film layer 20 on the substrate 10, the main template 40A and the patterned pattern are used to form the base 2 of the film layer for the mask. The environment between the two is set to a reduced pressure or a vacuum environment to reduce residual gas. However, in a high vacuum environment, the resist before curing may volatilize and there is a possibility that it is difficult to maintain a uniform film thickness. Therefore, it is preferable to set the environment between the main template and the substrate to a He environment or a decompression He environment. To reduce residual gases. Since He passes through the quartz substrate, the residual gas (He) that enters is gradually reduced. It takes time for the passage of He, so it is more preferable to set it as a decompression He environment. The reduced pressure environment is preferably from 1 kPa to 90 kPa, particularly preferably from 1 kPa to 10 kPa.

The main template 40A and the substrate 2 coated with the resist liquid 30 are aligned and brought into contact with each other so as to have a predetermined relative positional relationship. It is preferable to use an alignment mark when aligning.

The pressing pressure of the main template 40A is performed in a range of 100 kPa or more and 10 MPa or less. The pressure is large to promote the flow of the resist liquid, and also to promote the compression of the residual gas, the dissolution of the residual gas in the resist, and the transmission of He in the quartz substrate, thereby improving the removal rate of the residual gas. However, if the pressing force is too strong, when the main template is in contact, there is a possibility that the main template and the substrate having the patterned film layer for the mask are broken when the foreign matter is bitten. Therefore, the pressing pressure of the main template is preferably 100 kPa or more and 10 MPa or less, more preferably 100 kPa or more and 5 MPa or less, and particularly preferably 100 kPa or more and 1 MPa or less. The reason for setting it to 100 kPa or more is that, when embossing in the atmosphere, when the main template and the substrate with the pattern forming mask layer are filled with liquid, the main template and the substrate are at atmospheric pressure ( Pressurize at approximately 101 kPa).

<Curing Step b ₃ - b ₄ > After the main template 40A is pressed to form the resist film 32, exposure is performed with light having a wavelength corresponding to the polymerization initiator contained in the resist liquid to harden the resist. A resist pattern 35 is formed.

<Removal Step b ₅ > The main template 40A (release) is peeled off from the resist pattern 35 after hardening. The mold release method may be a method in which the holding portion of the outer edge or the holding portion of the back surface is oriented in a state in which one of the back surface or the outer edge portion of the main die plate 40A or the base body 10 is held while the other back surface or the outer edge portion is held. Relative movement in the opposite direction of the extrusion.

After the main template 40A is released from the mold, the residual film for removing the resist residual film formed at the bottom of the concave portion of the resist pattern 35 is etched, and then, step c of FIG. 4 is performed. The etching process of step d obtains the patterned substrate 10A. Each of these etching processes will be described. FIG. 6 is a schematic view showing an example of an etching apparatus 100 for performing each etching step.

The etching apparatus 100 includes a processing container (chamber) 101 that can maintain a further reduced pressure in a large air pressure, and a pressure reducing unit 103 that includes a pressure adjusting unit 102a for decompressing the inside of the processing container 101 to a predetermined pressure. An exhaust system 102b such as a vacuum pump; the base mounting structure portion 110 is disposed inside the processing container 101, and has a substrate to be processed placed thereon to support and fix the substrate to be processed; and a plasma generating portion 107 for generating plasma and including The high frequency power source 105 and the plasma generate antenna 106.

The base mounting structure portion 110 includes a lower electrode 112, and the present device 100 includes a bias power source 108 for imparting a bias voltage, and the bias power source 108 is coupled to the lower electrode 112 via a matching box 118. Further, the temperature adjuster 104 controls the temperature of the substrate mounting structure portion 110, and the gas introduction portion 109 includes a gas flow controller for introducing a desired gas into the processing container 101.

The etching performed by the device 100 is preferably RIE, and particularly the mechanism for generating plasma is preferably inductively coupled plasma (ICP)-RIE, capacitively coupled plasma (CCP)-RIE or electron cyclotron. Resonance type (ECR)-RIE. In the present embodiment, in order to easily control the bias power (the power for forming a bias voltage between the plasma and the lower electrode), a method that can be independently controlled with plasma power (power for forming plasma) is employed. .

(1) is used for etching residual film remaining film is etched using the steps of FIG. 5 b ₁ b ~ nanoimprint method step shown in Figure ₄ to form a resist pattern 35, the pattern formed on the bottom of the recessed portion of the The step of removing the residual film of the resist. The etching gas may use oxygen, argon or fluorocarbon gas.

(2) Etching of Thin Film Layer (Step c of Fig. 4) The etching step of the thin film layer 20 can be carried out in the same manner as the etching step of the thin film layer 50 in the patterned substrate manufacturing method of the first embodiment.

(3) Etching of the substrate (step d of FIG. 4) The step of etching the substrate 10 by using the mask pattern 25 obtained by patterning the thin film layer 20 as a mask may be the same as the pattern of the first embodiment. The etching step in the method of manufacturing the substrate is carried out in the same manner.

Through the above etching step, a concavo-convex pattern corresponding to the resist pattern 35 is formed on the surface of the substrate 10, whereby the concavo-convex patterned substrate 10A can be obtained. Further, in the method of manufacturing the patterned substrate 10A of the present embodiment, the patterned substrate 40A of the first embodiment is used as a master template for forming a resist pattern by an imprint method, and the master template can also be prepared in advance. Or use other methods to create. [Examples]

Hereinafter, examples and comparative examples of the present invention will be described.

<Preparation of Substrate for Patterning Mask Layer> As a substrate for patterning a film layer for a mask, a quartz substrate having a thickness of 152 mm square and a thickness of 6.35 mm is used, and is wet. Etching and forming a pedestal shape of 26 mm × 32 mm square and 30 μm in height at the center of the substrate of the quartz substrate as a transferred region, and having a diameter of 63 mm and a depth of 5 mm at the center of the back surface of the substrate Head hole.

A film layer for a mask is formed on the substrate by RF sputtering and by sputtering a chromium oxide into a film. In this case, the RF sputtering conditions are such that the base vacuum degree is 8.0×10 ⁻⁴ Pa or less, the RF power is 150 W, and the ratio of the degree of vacuum and the gas type at the time of film formation and the film thickness of the film are formed ( The target film thickness was changed in various manners as shown in the following Table 1, and the substrates of the film layers for patterning the masks of Examples 1 to 4 and Comparative Examples 1 to 13 were produced.

The composition of the film layer of each of the examples and the comparative examples can be determined by X-ray photoelectron spectroscopy performed while performing Ar etching in a region where the concave-convex pattern forming region of the subsequent step is not formed. Contains the depth distribution of the element. An example of the distribution is shown in FIG. In Fig. 7, the horizontal axis represents the sputtering time. t _f corresponds to the boundary position between the chromium oxide film layer and the quartz substrate. For each element, the depth dependence of the element content rate is measured, and the ratio of the value obtained by integrating the element content rate in the depth direction is defined as the film content ratio (atomic %) of each element, and the chromium as the entire film is obtained. Content rate (atomic %).

<Preparation of Patterned Substrate of Substrate Forming Mask Layer for Each of the Examples and Comparative Examples> The surface of the film layer of the substrate of the patterned film layer for patterning of each of the examples and the comparative examples, The surface treatment was carried out by using KBM-5103 (manufactured by Shin-Etsu Chemical Co., Ltd.), which is a decane coupling agent excellent in adhesion to a resist. Specifically, KBM-5103 was diluted to 1% by mass with propylene glycol 1-monomethyl ether 2-acetate (PGMEA), and was applied to a pattern by spin coating. The surface of the film layer of the base layer of the film layer for the mask was subjected to annealing on the hot plate at 150 ° C for 5 minutes on the surface of the film layer on which the film layer for the mask was applied, to form a decane coupling agent. Bonded to the surface of the substrate.

(Resist Pattern Forming Step) Here, resist pattern formation is performed by a nanoimprint method. As the main template, a groove having a width of 28 nm, a pitch of 56 nm, and a depth of 60 nm was formed in a 25 mm × 31 mm square in the center portion of a quartz substrate having a thickness of 0.25 inch and a thickness of 0.25 inch. The shape of the line pattern. The groove of the main template has a cone angle of 86°. For the surface of the master template, the mold release treatment was carried out by a dip coating method using Optool (registered trademark) DSX.

Preparation of 48% by weight of Compound A represented by the above formula (1), 48% by weight of Aronix (registered trademark) M220, 3 w% of IRGACURE (registered trademark) 379, 1 w% of the photocurable resist of the compound B represented by the chemical formula (2), and the resist is applied to the film of the substrate of the patterned film layer for each of the examples and the comparative examples. On the floor. For the application of the resist, DMP-2838 manufactured by FUJIFILM Dimatix Co., Ltd., which is a piezoelectric inkjet printer, was used. The inkjet head uses a dedicated 10 pl (picoliter) head, DMC-11610. The droplet arrangement pattern was set to a lattice pattern of 450 μm pitch. The discharge conditions are set and adjusted in advance, and droplets are placed on the transfer region (on the substrate pedestal) in accordance with the droplet arrangement pattern.

The main template and the substrate for patterning the mask film layer are brought close to a position where the gap is 0.1 mm or less, and the back surface of the substrate is aligned with the alignment mark on the main template from the back surface of the substrate. quasi. The space between the main template and the substrate for patterning the mask layer is replaced by He gas of 99% by volume or more, and after He replacement, the pressure is reduced to 50 kPa or less. The master template is contacted with droplets containing a resist under reduced pressure He conditions. After the contact, the pressure was applied for 5 seconds at a pressing pressure of 1 MPa, and then the UV light having a wavelength of 360 nm was used to expose the film so that the irradiation amount was 300 mJ/cm ² to cure the resist, and then the resist was cured. The main template is peeled off from the substrate with the film layer for patterning the mask.

After the resist pattern was formed by the nanoimprint method, the following etching and ashing were sequentially performed. Inductively coupled (ICP) reactive ion etching devices are used.

<Residual Film Etching> First, after the resist pattern is formed by the nanoimprint method, in order to remove the resist film remaining in the concave portion, residual film etching is performed by the etching conditions described below. Gas type: Oxygen: Argon = 2:1 Process pressure: 1 Pa ICP power: 100 W Bias power: 50 W Over-etching amount: 50%

<Etching of Thin Film Layer> Then, the resist pattern was used as a mask, and the thin film layer was etched under the etching conditions shown below to form a mask pattern. Gas type: Chlorine: Oxygen = 4:1 Process pressure: 4.5 Pa ICP power: 300 W Bias power: 5 W Over-etching amount: 100%

<Base (quartz) etching> Next, the mask pattern of the film layer was used as a mask, and the substrate (quartz) was etched under the etching conditions shown below. Gas type: CHF ₃ : SF ₆ : Ar=10:1:50 Process pressure: 3 Pa ICP power: 75 W Bias power: 75 W Target depth: 60 nm

<Mask Removal> Further, the mask removal was performed under the following conditions. Gas type: Chlorine: Oxygen = 3:1 Process pressure: 5 Pa ICP power: 100 W Bias power: 0 W

Through the above etching step, a concave-convex pattern was formed on the surface of the base of the substrate for patterning the mask layer of each of the examples and the comparative examples to form a patterned substrate.

(Evaluation) The patterned substrate prepared by forming the film layer for the mask layer of each of the examples and the comparative examples was observed by an electron microscope, and the following evaluation was performed. The upper surface (top-view) and the cross-section were observed, and the 3σ of the LER and the side wall angle were obtained from image analysis. Here, regarding the σ value of the LER, based on the plan view electron microscope image observed at 100,000 times, edge points (boundary points) of 500 line patterns at arbitrary positions are selected along the edge at intervals of 1 nm, according to the The coordinate information of the edge points is used to calculate the σ value of the LER. The operation is performed on any of the ten lines of the line pattern, and the average value thereof is used as the final σ value to determine the 3σ of the LER. The side wall angle is the side wall rising angle of the convex portion pattern, and the concave-convex boundary line of the pattern in the cross section is selected based on the cross-sectional image of the electron microscope observed at 150,000 times, and the vertex of the pattern convex portion and the bottom of the pattern concave portion are obtained. The inclination of the pattern edge boundary line at the position of the intermediate height. The inclination angle was obtained for any 10 points, and the average value was taken as the final side wall angle.

The case where the LER (3σ value) ≦ 2.8 nm and the side wall angle was 85° or more was evaluated as good (G), and the other cases were evaluated as defective (N). In addition, all of the inability to measure due to poor pattern formation were evaluated as defective (N).

Table 1 summarizes the film formation conditions of the film layer, the Cr content in the film layer, the LER of the patterned substrate, and the sidewall angle. Further, although the film layer was described as the target film thickness, it was confirmed that the actual film thickness was within ±5% with respect to the target film thickness. [Table 1]

In Comparative Example 8 to Comparative Example 9, in the mask pattern of the film layer, the film layer in the region to be the space portion (concave portion) was not sufficiently etched and remained, so that the uneven pattern could not be formed on the surface of the substrate. Further, in Comparative Examples 10 to 13, the etching resistance of the mask pattern of the film layer was weak, and the pattern of the uneven pattern on the surface of the substrate was poorly formed.

8 is a view in which the thickness of the film layer is taken as the vertical axis, and the chromium content in the film layer is plotted on the horizontal axis, and the examples and the comparative examples are plotted. In Fig. 8, the examples are shown by white circles (?), and the comparative examples are shown by black circles (?). Further, in FIG. 8, the scanning electron microscope images of the upper surface and the cross section of the uneven pattern on the surface of the patterned substrate of Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 10 are collectively shown. It was confirmed that Example 1 was formed with a concavo-convex pattern in which the LER was suppressed and the side wall angle was also good. On the other hand, it was confirmed that the side wall angles of Comparative Example 1, Comparative Example 2, and Comparative Example 10 were large and obtuse, and in particular, the height of the convex portion of Comparative Example 10 was extremely low, and the LER was also large.

As shown in FIG. 8 , in the region where the chromium content of the entire film surrounded by the broken line is 40 atom% or more, 50 atom% or less, and the thickness is 10 nm or less, the LER after the dry etching of quartz and the side wall angle are excellent, and The resistance of the etching mask can also be ensured, thus showing the effectiveness of the invention.

1, 2‧‧‧The base of the film layer for patterning the mask
10, 40‧‧‧ base
10A, 40A‧‧‧ patterned substrate
11‧‧‧ countersunk hole
12‧‧‧Deputy Department
15, 45‧‧‧ concave pattern
20, 50‧‧‧ film layer
25, 55‧‧‧ mask pattern
30‧‧‧resist solution
32‧‧‧resist film
35‧‧‧ Cover layer (resist pattern)
60‧‧‧resist layer
65‧‧‧ Cover layer (resist pattern)
100‧‧‧ etching device
101‧‧‧Processing container
102a‧‧‧ Pressure Adjustment Department
102b‧‧‧Exhaust system
103‧‧‧Decompression Department
104‧‧‧temperature adjuster
105‧‧‧High frequency power supply
106‧‧‧Plastic generating antenna
107‧‧‧The plasma generation department
108‧‧‧ bias power supply
109‧‧‧Gas introduction department
110‧‧‧Substrate mounting structure
112‧‧‧lower electrode
118‧‧‧match box

Fig. 1 is a cross-sectional view showing a base of a film layer for patterning a mask according to a first embodiment. Fig. 2 is a cross-sectional view showing a base of a film layer for patterning a mask according to a second embodiment; 3(a) to 3(f) are views showing a step of forming a patterned substrate by the base of the film layer for patterning the mask of the first embodiment. 4(a) to 4(e) are views showing a step of forming a patterned substrate by the base of the film layer for patterning the mask of the second embodiment. FIG. 5 (b ₁₎ ~ FIG. ₅ (b 5) is a view showing a step of forming a resist mask with a pattern on the base film layer by nano imprinting method in band patterns. Fig. 6 is a view showing a schematic configuration of an etching apparatus according to an embodiment of the etching method of the present invention. Fig. 7 is a view showing a content ratio distribution of a contained element of the thin film layer in the depth direction. 8 is a view in which the thickness of the film layer is taken as the vertical axis, and the chromium content in the film layer is plotted on the horizontal axis, and the examples and the comparative examples are plotted.

Claims (8)

A substrate having a film layer for patterning a mask, comprising: a substrate comprising a ruthenium or a lanthanide compound; and a film layer disposed on a surface of the substrate and using a plasma of a mixed gas of oxygen and chlorine It is patterned by etching to be used as a mask for pattern formation; and the thin film layer contains a chromium oxide having a chromium content of 40 at% or more and 50 at% or less, and has a thickness of 10 nm or less. A method of manufacturing a patterned substrate, which is prepared with a substrate patterned to form a film layer for a mask, the substrate of the patterned film layer for masking comprising a substrate comprising a ruthenium or a lanthanide compound and a film layer, the film layer Provided on the surface of the substrate, comprising a chromium oxide having a chromium content of 40 at% or more and 50 at% or less, and having a thickness of 10 nm or less; forming a mask layer for patterning on the film layer; The mask layer is etched by a plasma of a mixed gas of oxygen and chlorine, thereby patterning the thin film layer; and the patterned thin film layer is used as a mask The plasma of the fluorine-based gas is subjected to an etching treatment, thereby patterning the surface of the substrate. The method for producing a patterned substrate according to the second aspect of the invention, wherein the pattern line width in the patterning is 50 nm or less. The method for producing a patterned substrate according to claim 2, wherein a ratio of oxygen to chlorine in the mixed gas of oxygen and chlorine is 0.05 to 0.40. The method for producing a patterned substrate according to the second aspect of the invention, wherein the fluorine-containing gas content in the plasma containing the fluorine-based gas is 50% or less. The method for producing a patterned substrate according to claim 2, wherein the patterning mask layer is formed by applying a resist film on the film layer by using an imprint method. A concavo-convex pattern is formed on the resist film. The method of producing a patterned substrate according to any one of claims 2 to 6, wherein the patterned substrate is a nanoimprint template. The method of producing a patterned substrate according to any one of claims 2 to 6, wherein the patterned substrate is an optical element.