JP2003289060A - Cleaning liquid for substrate for semiconductor device and cleaning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide cleaning liquid and a cleaning method by which minute particles or an organic contaminant stuck on the surface of a substrate can be removed by cleaning without corroding the surface of the substrate and the surface thereof in highly cleaned in the substrate for a semiconductor device. <P>SOLUTION: The cleaning liquid for the substrate for a semiconductor device contains at least following elements (A), (B) and (C), and the cleaning method using the cleaning liquid is used. The element (A) is an ethylene oxide type surfactant that has a hydrocarbon group and polyoxyethylene that may have a substituent (excluding phenyl group) and wherein the ratio (m/n) of the carbon number (m) in the hydrocarbon group to the oxyethylene number in the polyoxyethylene group is 1 to 1.5, the carbon number (m) is 9 or more, and the oxyethylene number (n) is 7 or more, the element (B) is water, and the element (C) is an alkaline or an organic acid. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning liquid and a cleaning method for a semiconductor device substrate, and a substrate of semiconductor, glass, metal, ceramics, resin, magnetic material, superconductor, etc. in which metal contamination or particle contamination is a problem. The present invention relates to a cleaning liquid used for cleaning a surface. More specifically, the present invention relates to a cleaning liquid and a cleaning method for cleaning the surface of a semiconductor device substrate in the process of manufacturing a semiconductor device substrate for semiconductor elements or display devices, which requires a highly clean substrate surface. .

The cleaning liquid and cleaning method of the present invention are
A semiconductor device substrate having a semiconductor material such as silicon, an insulating material such as silicon nitride, silicon oxide, glass, a low dielectric constant (Low-k) material, or a transition metal or a transition metal compound on a part or the entire surface thereof. In addition, silica particles, alumina particles, fine particles (particles) such as organic particles, organic contaminants such as resist residues, and metallic contaminants attached to the substrate surface are removed, and reattachment is suppressed,
It can be highly cleaned without causing the surface of the substrate to be rough or corroded.

[0003]

2. Description of the Related Art In the process of manufacturing semiconductor devices such as flat panel displays such as TFT liquid crystal, microprocessors, memories and CCDs, the sub-micron or quarter-micron size is applied to the surface of a substrate such as silicon, silicon oxide (SiO ₂ ) and glass. Pattern formation and thin film formation are performed by. Therefore, in each of these manufacturing steps, it is extremely important to remove even a slight contamination of the surface of the substrate and highly clean the surface of the substrate.
Among the contaminations, it is difficult to remove all of the particulate contaminations and the metallic contaminations, which are minute contaminations. However, such contamination lowers the electrical characteristics and yield of semiconductor devices, so it is necessary to remove such contamination as much as possible before bringing it to the next step. And
To remove such contaminants, cleaning of the substrate surface with a cleaning liquid is generally performed.

In recent years, further improvement in throughput and improvement in production efficiency have been required in the manufacture of semiconductor devices.
For semiconductor device manufacturing substrates, which are becoming more and more miniaturized and highly integrated, the substrate surface is excellent not only in removing particle contamination and metal contamination on the substrate surface but also in preventing re-deposition after removal. A cleaning liquid and a cleaning method capable of highly cleaning a surface are desired.

It is generally known that an alkaline aqueous solution is effective as a cleaning liquid used for removing particle contamination. An alkaline aqueous solution such as an aqueous ammonia solution, an aqueous potassium hydroxide solution, or an aqueous tetramethylammonium hydroxide solution is used for cleaning the surface of the semiconductor device substrate. Also, ammonia, hydrogen peroxide,
Cleaning with a cleaning liquid containing water (referred to as "SC-1 cleaning liquid" or "APM cleaning liquid") ("SC-1 cleaning" or "A")
PM cleaning ". ) Is also widely used (see Non-Patent Document 1, for example).

Recently, in order to improve the performance of such an alkaline cleaning solution, specifically, the etching of the substrate surface for semiconductor devices is suppressed, the surface roughness is suppressed, and the wettability of the substrate surface is also improved. Various additions of various surfactants to the alkaline cleaning liquid have been proposed for the purpose of improving the removal property of particle contamination.

For example, in order to prevent the surface of the substrate from being roughened by the cleaning liquid, it has been proposed to add a surfactant to an alkaline aqueous solution of hydrogen peroxide so that the contact angle of the cleaning liquid with respect to the substrate surface is 10 degrees or less ( See, for example, Patent Document 1. Further, in order to improve the wettability of the cleaning liquid on the substrate surface, a hydrogen peroxide-containing alkaline cleaning liquid to which an ethylene oxide addition type nonionic surfactant having an ethylene oxide addition mole number of 3 to 10 is added has been proposed. (For example, see Patent Document 2).

Further, in order to suppress the etching of the surface of a silicon substrate, which is a typical semiconductor device substrate, it has been proposed to add various surfactants to an alkaline cleaning liquid (see, for example, Patent Document 3). In particular, a cleaning liquid used for cleaning a semiconductor device substrate containing a specific surfactant has been proposed in order to improve the performance of removing organic contaminants (see, for example, Patent Document 4). It has also been proposed to add alkylbenzene sulfonic acid to a hydrogen peroxide-containing alkaline cleaning liquid in order to improve the stain removal property (see, for example, Patent Document 5). In addition, it has been proposed to add a fluorine-based surfactant made of a fluoroalkylsulfonamide compound to the APM cleaning liquid in order to improve the particle removing property (see, for example, Patent Document 6).

In cleaning the semiconductor device substrate, an acidic cleaning liquid is also useful in addition to the above alkaline cleaning liquid. Generally, an acidic cleaning solution is effective for removing metal contamination on the substrate surface, but it is not suitable for removing particle contamination.Therefore, various surfactants are used in the acidic cleaning solution for the purpose of improving the ability to remove particle contamination. Has been proposed. For example, it has been proposed to clean a silicon wafer using a specific surfactant and hydrofluoric acid (see, for example, Patent Document 7).

Further, it has been proposed to add a surfactant and ozone to a hydrofluoric acid aqueous solution used for cleaning a silicon wafer (see, for example, Patent Document 8). It has also been proposed to add an organic acid compound to a dispersant and / or a surfactant in order to remove metal impurities and particle contamination adsorbed on a substrate having a metal wiring on its surface (see, for example, Patent Document 9).

In recent years, with the miniaturization and high stacking of semiconductor devices, wiring (hereinafter, simply referred to as “wiring”) connecting minute semiconductor elements in the semiconductor device,
New metal materials such as copper (Cu) and tungsten (W) are being introduced as metal materials used for electrodes (hereinafter, simply referred to as “electrodes”) in semiconductor elements. Specifically, for example, as a wiring material, Cu having a lower resistance value than that of aluminum (Al) which has been conventionally used is being adopted.

Another novel material is an interlayer insulating film between semiconductor elements having a laminated structure. As this interlayer insulating film, a low dielectric constant film using a film made of an organic polymer material or an inorganic polymer material having a lower dielectric constant than that of a conventionally used SiO ₂ film is being adopted. This interlayer insulating film is used in a substrate cleaning process (hereinafter, may be referred to as a “post process”) performed after the metal wiring is formed on the surface of the semiconductor device during the manufacturing process.
It is exposed on the board together with the wiring.

Further, tungsten is being introduced into electrodes as an electrode material having a low resistance value and advantageous for fine processing. The electrodes are usually exposed on the surface of the substrate during the step of cleaning the substrate before forming the metal wiring (hereinafter sometimes referred to as “pre-process”). Conventionally, the surface of the substrate to be cleaned in the previous step was entirely composed of a Si compound, and therefore even slight contamination affects the semiconductor device, so that it was necessary to highly clean the surface of the substrate. Therefore, strong cleaning by RCA cleaning is essential.

In recent years, attempts have been made to apply the above-mentioned various proposals in order to highly clean even a substrate in which the above-mentioned new material is exposed on the surface.

[0015]

[Non-Patent Document 1] W. Kern and DAPuotinen: RCA Revie
w, p.187, June (1970)

[Patent Document 1] JP-A-5-335294

[Patent Document 2] Japanese Patent No. 3169024

[Patent Document 3] JP 2001-40389 A

[Patent Document 4] Japanese Patent Laid-Open No. 11-121418

[Patent Document 5] Japanese Patent Laid-Open No. 7-245281

[Patent Document 6] JP-A-5-251416

[Patent Document 7] JP-A-7-216392

[Patent Document 8] Japanese Unexamined Patent Publication No. 8-69990

[Patent Document 9] Japanese Patent Laid-Open No. 2001-7071

[0016]

In the conventional post-process using Al wiring, the Al wiring is vulnerable to strong acid and strong alkali, and the influence of metal contamination is lower than that in the previous step.
Only simple cleaning with ultrapure water or organic solvent was performed. However, when Cu is used instead of Al, the following two problems newly arise.

First, Cu is one of the pollutants most disliked by Si, and the oxide film (Si
The diffusion rate of Cu in the (O ₂ film) is high, and the adverse effect thereof is far higher than that of Al.

Secondly, unlike Al, Cu cannot be dry-etched, which is a problem. In order to form a wiring made of Cu, an insulating film having a groove (for forming a Cu wiring) previously formed is subjected to Cu plating to form a wiring, and then,
Unnecessary parts are CMP (Chemical Mechanical)
There is no choice but to form a wiring by a so-called damascene method, which is a scraping method such as cal polishing).

In the wiring formation by the damascene method described above, a large amount of Cu and polishing particles (particles typified by aluminum oxide particles) in the slurry used for CMP are used.
However, contamination of the Cu wiring and the surface of the low dielectric constant film poses a problem. Such contamination of the substrate surface can no longer be removed by simple cleaning with ultrapure water or an organic solvent, which is a serious problem.

When the conventional RCA cleaning with a strong acid or a strong alkali is carried out against the above-mentioned contamination, a new problem arises that new metal materials such as Cu and W are dissolved in hydrogen peroxide. Was there. Further, since the surface of the low dielectric constant film is hydrophobic, the wettability of the cleaning liquid is poor and the cleaning liquid is repelled, and in particular, it is difficult to sufficiently remove the particle contamination.

Therefore, in the step of cleaning the substrate having the above-mentioned new material on its surface, hydrogen peroxide water will be contained in the future.
There are serious problems such as the inability to clean using RCA cleaning liquid. When cleaning a substrate with a new metal material that is weak against chemicals such as hydrogen peroxide on the surface, the development of a new cleaning liquid is strongly desired. It is rare.

On the other hand, as described above, a cleaning liquid containing a surfactant has been developed. However, in addition to the removal of metal contamination and the removal of particle contamination, re-deposition prevention is sufficiently performed, and a cleaning liquid satisfying the problems described in (1) to (3) below has never been available in the surface cleaning of a substrate. It was a challenge to get rid of.

(1) At room temperature or at the time of heating, the surfactant does not become oil droplets in the cleaning liquid and are not deposited or clouded, and the cleaning performance is not deteriorated and the oil droplets do not remain on the substrate surface. . (2) The foamability is small and does not adversely affect the operation of the cleaning device. (3) The surfactant is a substance that does not adversely affect the natural environment, and the cleaning waste liquid can be appropriately treated.

For example, since anionic surfactants generally have no cloud point, it is possible to use the cleaning liquid at a high temperature (for example, 80 ° C. or higher) in expectation of high cleaning effect. However, since it is highly foamable, it may adversely affect the operability of the cleaning device.

The nonionic surfactant has high cleaning performance and low foaming property, but its cloud point is generally low. Therefore, when a high cleaning effect is expected and cleaning is performed at a high temperature of the cleaning liquid, this surfactant appears as oil drops in the cleaning liquid and remains on the substrate.

[0026]

Means for Solving the Problems With respect to the above-mentioned problems, the present inventors diligently studied a semiconductor device substrate cleaning liquid using a surfactant. In particular, attention was paid to the surfactant used in the cleaning liquid, especially to the ethylene oxide type surfactant which is a nonionic surfactant.

The ethylene oxide type surfactant has a hydrocarbon group and a polyoxyethylene group in the same molecular structure. In the ethylene oxide type surfactant having such a structure, the present inventors have found the ratio of the number of carbon atoms (m) contained in the hydrocarbon group to the number of oxyethylene groups (n) in the polyoxyethylene group. Focusing on surfactants within a specific range satisfying the conditions that (m / n) is 1 to 1.5, carbon number (m) is 9 or more, and oxyethylene group number (n) in polyoxyethylene group is 7 or more. .

Many of the ethylene oxide type surfactants within this specific range are solid and have low solubility in water under the conditions of room temperature and atmospheric pressure. Therefore, such an ethylene oxide type surfactant has low handleability in an industrial production process, and its use has been avoided. But,
Such a semiconductor device substrate cleaning liquid containing an alkali or an organic acid prepared by heating and melting an ethylene oxide type surfactant within a specific range and dissolving it in water,
Surprisingly, it showed good cleaning performance without containing hydrogen peroxide. In particular, it was excellent in cleanability against fine particle contamination (removability of particles having a particle size of 0.1 μm order), which cannot be predicted from a general stain cleaning effect. Moreover, the above-mentioned semiconductor device substrate cleaning liquid is easy to repel an aqueous cleaning liquid because of its hydrophobicity, and exhibits sufficient wettability even to a low dielectric constant film surface with low particle removability,
It has an excellent cleaning effect. The present inventors have found these things and completed the present invention.

That is, the gist of the present invention is at least:
A cleaning liquid for a substrate for a semiconductor device and a cleaning method using the cleaning liquid are characterized by containing the following components (A), (B) and (C).

Component (A): Substituent (excluding phenyl group)
Having a hydrocarbon group and a polyoxyethylene group which may have, a ratio of the number of carbon atoms (m) in the hydrocarbon group and the number of oxyethylene groups (n) in the polyoxyethylene group (m /
n) is 1 to 1.5, the number of carbon atoms (m) is 9 or more, and the number of oxyethylene groups (n) is 7 or more, an ethylene oxide type surfactant. Component (B): Water Component (C): Alkali or organic acid

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The cleaning liquid of the present invention contains at least a specific surfactant as the component (A), water as the component (B), and an alkali or organic acid as the component (C).

In the present invention, the surfactant used as the component (A) has a hydrocarbon group which may have a substituent (excluding phenyl group) and a polyoxyethylene group, and The ratio (m / n) of the number of carbon atoms (m) in the hydrogen group and the number of oxyethylene groups (n) in the polyoxyethylene group is 1
It is an ethylene oxide type surfactant having a carbon number (m) of 9 or more and an oxyethylene group number (n) of 7 or more.

When the ratio (m / n) is less than 1,
The ability to remove particles in the liquid and the suppression of silicon corrosion are insufficient. In addition, the solubility in water decreases due to the increase in oxyethylene chain length, and the load of waste liquid treatment also increases. On the other hand, if it exceeds 1.5, it becomes O when washed in an alkaline solution.
A / W type emulsion is formed, and the surfactant is deposited as fine oil droplets and becomes cloudy, which causes problems such as deterioration of cleaning performance and residual oil droplets. Ratio (m / n)
Is preferably 1 to 1.4.

When the carbon number (m) is less than 9,
Even if the (m / n) ratio is within the optimum range, the particle removability is deteriorated. If (m) is too large,
It is not preferable because the solubility in water decreases and the load of waste liquid treatment increases. Therefore, the carbon number (m) is preferably 9 to
16, more preferably 10-14. However, when the hydrocarbon group constituting the component (A) has a hydrocarbon group as a substituent, the total number of carbon atoms in the hydrocarbon group as the main chain and the hydrocarbon group as the substituent is m. And

If (n) is less than 7,
Even if the (m / n) ratio is within the optimum range, the particle removability is deteriorated. When (n) is too large, the load of waste liquid treatment becomes large, and the surfactant is easily decomposed in the cleaning liquid. Therefore, (n) is preferably 7-1.
6, and more preferably 7 to 14.

By using the above ethylene oxide type surfactant defined in the present invention, both the wettability of the cleaning liquid and the removability of particles are improved. Examples of the above ethylene oxide type surfactants include polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene alkylamine, and polyoxyethylene alkyl ether sulfate. In particular, polyoxyethylene alkyl ether represented by the following general formula (II) is preferable from the viewpoints of removability of particle contamination and anti-redeposition ability.

[0037]

Embedded image R ² O— (CH ₂ CH ₂ O) _n H (II) (wherein R ² represents a hydroxyl group, an amino group, an alkoxy group, or an alkyl group which may be substituted with halogen, The number of carbon atoms (m) contained in the group is 9 or more,
(N) represents a number of 7 or more. )

Specific examples of the above polyoxyethylene alkyl ether include polyoxyethylene (n = 8) nonyl ether, polyoxyethylene (n = 9) decyl ether, polyoxyethylene (n = 11) undecyl ether, Polyoxyethylene (n = 10) lauryl ether, polyoxyethylene (n = 11) lauryl ether, polyoxyethylene (n = 10) tridecyl ether, polyoxyethylene (n = 12) tridecyl ether, polyoxyethylene ( n = 11) tetradecyl ether, polyoxyethylene (n = 13) tetradecyl ether, polyoxyethylene (n = 12) pentadecyl ether, polyoxyethylene (n = 14) pentadecyl ether, polyoxyethylene (n = 12) Cetyl ether, polyoxy Ethylene (n = 15) cetyl ether, polyoxyethylene (n = 18) oleyl ether, and the like. In addition, the numerical value in said n represents n in the said General formula (II).

In the present invention, a plurality of ethylene oxide type surfactants having different (m) and (n) may be used in combination at any ratio within the scope of the present invention. Furthermore, when a plurality of kinds of surfactants are used in combination, (m /
The average value of n) is 1 to 1.5, the average value of (m) is 9 or more,
If the average value of (n) satisfies the condition of 7 or more, (m / n) is less than 1.0 or 1.
5 is exceeded, (m) is less than 9, and (n) is 7
It may be less than.

The content of the component (A) in the cleaning liquid is
Usually 0.0001 to 1% by weight, preferably 0.0003
To 0.5% by weight, more preferably 0.001 to 0.1% by weight, and particularly preferably 0.001 to 0.05% by weight. If the component (A) concentration is too low, the particle contamination removal performance is not sufficient, while if the component (A) concentration is too high, there is no change in the particle contamination removal performance and foaming becomes noticeable. It may be unsuitable for the process, and the load when biodegrading waste liquid may increase.

The component (A) may contain metal impurities such as Na, K and Fe in an amount of about 1 to several thousand ppm in a commercially available form. In such a case, the component (A) becomes a metal pollution source. Therefore, the surfactant used as the component (A) is preferably purified before use. The content of each metal impurity is usually 10 pp.
m or less, preferably 1 ppm or less, more preferably 0.
It is set to 1 ppm or less. As a purification method, for example, after the surfactant is dissolved in water, it is passed through an ion exchange resin,
A method of trapping metal impurities in the resin is suitable.

By using the component (A) purified as described above, it is possible to obtain a cleaning liquid in which the content of metal impurities is extremely reduced. The cleaning liquid of the present invention includes at least Na, Mg, and A among the metal impurities in the cleaning liquid.
The content of each of l, K, Ca, Fe, Cu, Pb, and Zn is 20 ppb or less, especially 5 ppb or less, and particularly 0.1.
It is preferably ppb or less.

In the present invention, a surfactant other than the component (A) may be used as long as the effect of the present invention is not impaired. The surfactant other than the component (A) may be any of a cationic surfactant, an anionic surfactant and a nonionic surfactant. Above all, it is preferable to use an anionic surfactant or a nonionic surfactant. Specifically, for example, as the anionic surfactant, an alkylbenzenesulfonic acid having 8 to 12 carbon atoms and its Examples thereof include salts, alkylmethyl tauric acid having 8 to 12 carbon atoms and salts thereof, alkyl sulfuric acid esters having 8 to 12 carbon atoms and salts thereof, and the like. Examples of nonionic surfactants include surfactants composed only of polyoxyalkylene.

In the present invention, water is used as the component (B). When it is desired to obtain a highly clean substrate surface, deionized water, preferably ultrapure water, is usually used. Further, electrolytic ion water obtained by electrolysis of water, hydrogen water in which hydrogen gas is dissolved in water, or the like can also be used.

In the present invention, an alkali or organic acid is used as the component (C). That is, the cleaning liquid of the present invention is an alkaline cleaning liquid or an acidic cleaning liquid.

The type of alkali used in the present invention is not particularly limited, but typical alkalis include ammonium hydroxide (aqueous ammonia solution) and organic alkalis. Examples of the organic alkali include amines such as quaternary ammonium hydroxide, amines and amino alcohols. As the quaternary ammonium hydroxide, a hydroxyl group,
Those having an alkoxy group, an alkyl group having 1 to 4 carbon atoms which may be substituted with a halogen, or a hydroxyalkyl group having 1 to 4 carbon atoms are preferable, and all of these substituents may be the same or different.

Examples of the alkyl group as described above include a methyl group, an ethyl group, a propyl group, a butyl group and the like having 1 to 1 carbon atoms.
4 lower alkyl groups, and examples of the hydroxyalkyl group include a hydroxymethyl group, a hydroxyethyl group,
Examples thereof include lower hydroxyalkyl groups having 1 to 4 carbon atoms such as hydroxypropyl group and hydroxybutyl group.

Specific examples of the quaternary ammonium hydroxide having the above substituents include tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, trimethyl (hydroxyethyl) ammonium hydroxide (common name: choline), Examples include triethyl (hydroxyethyl) ammonium hydroxide. On the other hand, examples of amines include ethylenediamine, monoethanolamine, trimethanolamine and the like.

Among the above-mentioned alkalis, ammonium hydroxide, tetramethylammonium hydroxide (TMAH), trimethyl (hydroxyethyl) ammonium are used for the reasons of cleaning effect, less residual metal, economy, stability of cleaning solution, etc. Hydroxide (common name: choline) is preferred. These alkalis may be used alone or in any combination of two or more.

The concentration of the alkali in the cleaning liquid may be appropriately selected, but it is preferable that the pH of the cleaning liquid is 9 or more to be alkaline. Alkali concentration is too low p
If H is not high, the effect of removing contaminants, which is the object of the present invention, may not be obtained. On the other hand, if the pH is too high, the effect of increasing the pH cannot be obtained, which is economically disadvantageous, and the risk of damaging the substrate surface by etching increases, which is not preferable. Therefore, the pH of the alkaline cleaning liquid is preferably 9 to 13, more preferably 10 to 12.5, and particularly preferably 10.5 to 12.

The type of organic acid used in the present invention is not particularly limited, but organic carboxylic acid or organic sulfonic acid is preferable. Typical organic carboxylic acids include:
Formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid,
Ethylmethylacetic acid, trimethylacetic acid, oxalic acid, succinic acid,
Malonic acid, citric acid, tartaric acid, malic acid and the like can be mentioned. Among these, one or more selected from the group of acetic acid, propionic acid, oxalic acid, succinic acid, malonic acid, citric acid, tartaric acid and malic acid are preferable, and selected from the group of acetic acid, oxalic acid and citric acid. More preferably, one kind or two or more kinds are used. Acetic acid is used as an etchant material for a semiconductor substrate, etc., and is most preferable in that it can be obtained at a low cost with high purity and a small amount of metal impurities by a distillation operation, and powder generation due to water evaporation does not occur.

Typical organic sulfonic acids include:
Examples thereof include methanesulfonic acid, ethanesulfonic acid, n-propanesulfonic acid, i-propanesulfonic acid, n-butanesulfonic acid and phenylsulfonic acid. Of these, methanesulfonic acid and / or ethanesulfonic acid are preferable, and methanesulfonic acid is particularly preferable. The above organic acids may be used alone or in any combination of two or more.

The concentration of the organic acid in the cleaning liquid may be appropriately selected, but it is preferable that the acidic cleaning liquid has a pH of 1 to 5. If the concentration of the organic acid is too low and the pH is not sufficiently low, the effects of removing contaminants and preventing adhesion, which are the objects of the present invention, may not be obtained. On the other hand, if the concentration is too high, the effect of lowering the pH cannot be obtained, which is economically disadvantageous and may cause corrosion of the substrate surface, which is not preferable. The pH of the acidic cleaning liquid is preferably 2-3.

In the cleaning liquid of the present invention, it is preferable to include a complexing agent because a highly highly cleaned surface with further reduced metal contamination on the substrate surface can be obtained. Any conventionally known complexing agent can be used. The type of complexing agent may be selected by comprehensively judging from the contamination level of the substrate surface, the type of metal, the cleanliness level required for the substrate surface, the cost of the complexing agent, the chemical stability, etc. ,
The following (1) to (4) are listed.

(1) Compounds having nitrogen as a donor atom and carboxyl group and / or phosphonic acid group: for example, amino acids such as glycine; iminodiacetic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid [EDTA], trans-1 , 2-diaminocyclohexanetetraacetic acid [CyDT
A], nitrogen-containing carboxylic acids such as diethylenetriamine pentaacetic acid [DTPA], triethylenetetramine hexaacetic acid [TTHA]; ethylenediaminetetrakis (methylenephosphonic acid) [EDTPO], nitrilotris (methylenephosphonic acid) [NTPO], propylenediaminetetra Examples thereof include nitrogen-containing phosphonic acids such as (methylenephosphonic acid) [PDTMP].

(2) A compound having an aromatic hydrocarbon ring and having two or more OH groups and / or O ⁻ groups directly bonded to the carbon atoms constituting the aromatic hydrocarbon ring:
Examples thereof include phenols such as catechol, resorcinol, Tyrone, and their derivatives.

(3) Compound having both the structures of (1) and (2) above:

(3-1) Ethylenediaminedioltohydroxyphenylacetic acid [EDDHA] and its derivatives: For example, ethylenediaminedioltohydroxyphenylacetic acid [EDDHA], ethylenediamine-N, N'-bis [(2-hydroxy-5-methyl) (Phenyl) acetic acid] [E
DDHMA], ethylenediamine-N, N'-bis [(2-hydroxy-5-chlorophenyl) acetic acid] [E
DDHCA], ethylenediamine-N, N'-bis [(2-hydroxy-5-sulfophenyl) acetic acid] [E
Aromatic nitrogen-containing carboxylic acids such as DDHSA]; ethylenediamine-N, N'-bis [(2-hydroxy-5-methylphenyl) phosphonic acid], ethylenediamine-N,
N'-bis [(2-hydroxy-5-phosphophenyl)
And aromatic nitrogen-containing phosphonic acids.

(3-2) N, N'-bis (2-hydroxybenzyl) ethylenediamine-N, N'-2acetic acid [H
BED] and its derivatives: For example, N, N′-bis (2
-Hydroxybenzyl) ethylenediamine-N, N'-
Diacetic acid [HBED], N, N'-bis (2-hydroxy-5-methylbenzyl) ethylenediamine-N, N'-
Diacetic acid [HMBED], N, N′-bis (2-hydroxy-5-chlorobenzyl) ethylenediamine-N, N ′
-2 acetic acid etc. are mentioned.

(4) Others: For example, amines such as ethylenediamine, 8-quinolinol and o-phenanthroline; carboxylic acids such as formic acid, acetic acid, oxalic acid and tartaric acid; hydrofluoric acid, hydrochloric acid, hydrogen bromide and iodide. Hydrogen halide such as hydrogen and salts thereof; oxo acids such as phosphoric acid and condensed phosphoric acid; salts thereof and the like.

The complexing agent may be used in the acid form or in the salt form such as ammonium salt.

Among the complexing agents mentioned above, ethylenediaminetetraacetic acid [E] is used for reasons such as cleaning effect and chemical stability.
Nitrogen-containing carboxylic acids such as DTA] and diethylenetriamine pentaacetic acid [DTPA]; Nitrogen-containing phosphonic acids such as ethylenediaminetetrakis (methylenephosphonic acid) [EDTPO] and propylenediaminetetra (methylenephosphonic acid) [PDTMP]; Acetic acid [EDDHA] and its derivatives;
N, N'-bis (2-hydroxybenzyl) ethylenediamine-N, N'-2 acetic acid [HBED] is preferred.

Among them, from the viewpoint of cleaning effect, elenediamine diorthohydroxyphenylacetic acid [EDDHA], ethylenediamine-N, N'-bis [(2-hydroxy-5)
-Methylphenyl) acetic acid] [EDDHMA], diethylenetriamine 5 acetic acid [DTPA], ethylenediamine 4
Acetic acid [EDTA] and propylenediaminetetra (methylenephosphonic acid) [PDTMP] are preferred. The above complexing agents may be used alone or in any combination of two or more.

The concentration of the complexing agent in the cleaning liquid may be arbitrarily selected depending on the kind and amount of the contaminating metal impurities and the cleanliness level required for the substrate surface, but it is usually 1 to 10000 pp.
m, preferably 5-1000 ppm, more preferably 1
It is 0 to 200 ppm. If the concentration of the complexing agent is too low, the effect of removing the contamination and preventing the adhesion by the complexing agent cannot be obtained,
If it is too high, the effect corresponding to the increase in the concentration cannot be obtained, which is economically disadvantageous, and the risk that the complexing agent adheres to the substrate surface and remains after the surface treatment increases.

Since the complexing agent contains metal impurities such as FeAl and Zn of about 1 to several thousand ppm in the commercially available reagents, the complexing agent used in the present invention is a metal. It may be a source of pollution. These metals are
It exists in the initial stage in the form of a stable complex with a complexing agent, but when the complexing agent decomposes during long-term use as a surface cleaning solution, it is released and adheres to the substrate surface. Therefore, the complexing agent used in the present invention is preferably purified before use. The content of each of the metal impurities contained is usually 5 ppm or less, preferably 1 ppm or less, and more preferably 0.1 ppm or less. As a purification method, for example, a method of dissolving the complexing agent in an acidic or alkaline solution, removing insoluble impurities by filtration, neutralizing again to precipitate crystals, and separating the crystals from the liquid are preferable. is there.

Further, the cleaning liquid of the present invention may contain other components in an arbitrary ratio as long as the performance thereof is not impaired. Other components include sulfur-containing organic compounds (2-mercaptothiazoline, 2-mercaptoimidazoline, 2-mercaptoethanol, thioglycerol, etc.), nitrogen-containing organic compounds (benzotriazole, alkylbenzotriazole, tetrazole, 3-aminotriazole). , N (R) ₃ (R is an alkyl group having 1 to 4 carbon atoms), N (ROH) ₃ (R is an alkyl group having 1 to 4 carbon atoms), urea, thiourea, etc., a water-soluble polymer (polyethylene glycol, Polyvinyl alcohol, etc., anti-corrosion agents such as alkyl alcohol compounds (ROH (R is an alkyl group having 1 to 4 carbon atoms)), acids such as sulfuric acid and hydrochloric acid, reducing agents such as hydrazine, dissolved hydrogen, argon, nitrogen, etc. Polymer, etc. firmly adhered after dry etching such as gas, hydrofluoric acid, ammonium fluoride, BHF, etc. Etching accelerators and the like that can be expected to have the effect of removing

Other components to be contained in the cleaning liquid of the present invention include oxidizing agents such as hydrogen peroxide, ozone and oxygen. In the process of cleaning semiconductor device substrates,
When the surface of a silicon (bare silicon) substrate without an oxide film is washed, the surface roughness due to etching on the surface of the substrate can be suppressed by mixing an oxidizing agent, which is preferable. When the alkaline cleaning solution of the present invention contains hydrogen peroxide, the concentration of hydrogen peroxide in the cleaning solution is usually 0.0
The amount is 1 to 5% by weight, preferably 0.1 to 1% by weight.

On the surface of the substrate to be cleaned, the wiring of the semiconductor device and the device element electrode made of a metal material which reacts with hydrogen peroxide to be dissolved may be exposed. Examples of such a metal material include transition metals or transition metal compounds such as Cu and W. At this time, it is preferable that the cleaning liquid used for cleaning contains substantially no hydrogen peroxide. The cleaning liquid of the present invention is
Unlike PM cleaning liquid, even if it does not substantially contain hydrogen peroxide, it does not adversely affect such metallic materials,
Shows sufficient cleaning performance.

In the cleaning liquid of the present invention, "substantially free of hydrogen peroxide" means the material on the substrate to be cleaned, such as the wiring material or electrode material such as Cu or W, and the low dielectric constant. This means that the film is not adversely affected by hydrogen peroxide such as corrosion and deterioration. That is, it means that these materials sufficiently function as wirings and electrodes when used as a semiconductor device. For that purpose, it is preferable that the cleaning liquid of the present invention does not contain hydrogen peroxide, and even if it is contained, the content thereof is suppressed to be small. The content is, for example, 10 ppm or less, preferably 1 p
pm, and more preferably 10 ppb or less.

The cleaning liquid of the present invention is used for cleaning the substrate surface of semiconductors, glass, metals, ceramics, resins, magnetic materials, superconductors, etc., where metal contamination or particle contamination is a problem. Particularly, it is suitably used for cleaning the surface of a semiconductor device substrate in the process of manufacturing a semiconductor device substrate for semiconductor elements, display devices, etc., which requires a highly clean substrate surface. Wiring, electrodes, etc. may be present on the surface of these substrates. As the material for the wirings and electrodes, semiconductor materials such as Si, Ge and GaAs; SiO ₂ , silicon nitride, glass, low dielectric constant materials,
Aluminum oxide, transition metal oxides (titanium oxide, tantalum oxide, hafnium oxide, zirconium oxide, etc.),
Insulating materials such as (Ba, Sr) TiO ₃ (BST), polyimide and organic thermosetting resins; metals such as W, Cu and Al or alloys thereof, silicides, nitrides and the like. The low dielectric constant material is a general term for materials having a relative dielectric constant of 3.5 or less. Incidentally, the relative permittivity of SiO ₂ is 3.8.
˜3.9.

In particular, the cleaning liquid of the present invention is suitably used for cleaning a semiconductor device substrate having a transition metal or a transition metal compound on the surface. Transition metals include W and C
u, Ti, Cr, Co, Zr, Hf, Mo, Ru, A
Examples of the transition metal compound include u, Pt, and Ag, and examples of the transition metal compound include nitrides, oxides, and silicides of these transition metals. Among these, W and / or Cu are preferable.

Examples of the step of cleaning the substrate having tungsten on the surface include cleaning of the surface of the substrate having the gate electrode and silicon when tungsten is used as the gate electrode material. Specifically, a cleaning step after forming a tungsten film on a semiconductor device, in particular, a cleaning step after dry etching the tungsten film, and a cleaning step after ion implantation into a silicon exposed portion are mentioned.

By using the cleaning liquid of the present invention, it is possible to remove particles and metals without performing ultrasonic irradiation or brush scrubbing. Therefore, the cleaning liquid of the present invention is highly likely to be broken when ultrasonic cleaning or brush scrubbing is performed, and therefore, when an extremely fine gate electrode (for example, a gate electrode width is about 0.15 μm) is formed of tungsten. Suitable for cleaning the gate electrode and the substrate surface.

The step of cleaning the substrate having Cu on the surface includes Cu when Cu is used as a wiring material.
The cleaning of the surface of the substrate having the wiring and the interlayer insulating film may be mentioned. Specifically, the cleaning step after forming the Cu film on the semiconductor device, particularly the CMP (Chemical MMP) for the Cu film.
Examples include a cleaning step after performing echanical polishing) and a cleaning step after forming a hole in the interlayer insulating film on the wiring by dry etching.

The cleaning liquid of the present invention is also suitably used for cleaning a semiconductor device substrate having a low dielectric constant material serving as an interlayer insulating film material on its surface. Low dielectric constant materials include organic polymer materials and inorganic polymers (siloxane-based)
Materials and porous materials are roughly classified into three types. Organic polymer materials include Polyimide and BCB
(Benzocyclobutene), Flare (Honeywell), SiLK (Dow C)
hemical) and the like, and examples of the inorganic polymer material include F
SG (Fluorinated silicate glass), BLACK DIAMOND (Ap
plied Materials), Aurora (Japan ASM), etc.

As described above, the cleaning liquid of the present invention is suitably used for cleaning the surface of a semiconductor device substrate regardless of the presence or absence of electrodes or wiring materials on the substrate surface. Among them, the cleaning liquid of the present invention is preferably used for cleaning a semiconductor device substrate having a hydrophobic contact angle of 60 ° or more on the surface of the substrate.

The cleaning solution of the present invention may be prepared by a conventionally known method. Of the constituents of the cleaning liquid (for example, surfactant, ammonium hydroxide, water, and other components such as complexing agent if necessary), any two or three or more components are mixed in advance, and then the remaining components are mixed. The components may be mixed or all at once.

As described above, the semiconductor device substrate cleaning solution of the present invention can be applied to new materials for the future, that is, even for semiconductor device substrates having a metal material having low resistance to a chemical solution such as hydrogen peroxide on the surface. Since the material is not substantially corroded, the cleaning liquid can be used in both the pre-process and the post-process and has an excellent cleaning effect.

That is, another aspect of the present invention is for a semiconductor device having at least a semiconductor element electrode or a metal wiring on the surface, which satisfies the following conditions (a), (b) and (c): It exists in the substrate cleaning solution.

(A) Substantially no corrosion of semiconductor element electrodes and metal wiring. (B) The amount of contaminating metal is 1000 to 5000 (× 10 ¹⁰ a
In the case of cleaning a substrate having a thickness of 10 (toms / cm ² ), the amount of contaminated metal after cleaning is 10 (× 10 ¹⁰ atoms)
/ Cm ² ) or less. (C) Particles having a particle size of 0.1 μm or more
In the case where a substantially circular substrate surface having a radius r of 100,000 (pieces / 0.03 m ² ) is washed for t (minutes), particles in a circle on the substrate surface having the same center as the substrate after cleaning When the number is t = 0.5 to 1, the circumference radius is 0.
It is 200 / t or less within the circumference of 6r, or 800 / t or less within the circumference of a radius of 0.9r.

The above definitions of (b) and (c) are as follows.
The characteristics of the cleaning liquid of the present invention are specified, and the cleaning conditions under which the cleaning liquid of the present invention is used are not specified.
Further, in the cleaning liquid of the present invention, "substantially does not corrode the semiconductor element electrode and the metal wiring" means that the semiconductor element electrode and the metal wiring on the substrate to be cleaned, specifically, such as W and Cu. It means that these materials do not cause adverse effects such as corrosion and alteration to the electrode material and the wiring material, and that these materials sufficiently function as electrodes and wiring when used as a semiconductor device.

Satisfaction of the conditions (b) and (c) in the above-mentioned cleaning liquid of the present invention means that metal contamination, particle contamination and any contamination can be sufficiently removed. .

The condition (c) is that when the object to be cleaned is the surface of the substantially disk-shaped substrate, that is, the surface of the substantially circular substrate, even if the cleaning is performed for a short time, the substrate surface is highly advanced regardless of the position of the substrate surface. It means that it can be cleaned. That is, particles having a particle diameter of 0.1 μm or more are 8000 to 100000 (particles / 0.0
After cleaning a substantially circular substrate surface having a radius r of 3 m ² ) for a cleaning time t: 0.5 to 1 [minutes], a circumferential radius which is a relatively inner peripheral portion on the substrate surface having the same center as the substrate Within the circumference of 0.6r, 200 particles remain
/ T particles or less, and even within the circumference with a radius of 0.9r including even the outer peripheral portion, the number of particles should be 800 / t or less, and the substrate surface can be highly cleaned. Means

In the above-mentioned semiconductor device substrate cleaning liquid of the present invention, "when cleaned" means that the semiconductor device substrate is cleaned with the cleaning liquid by a cleaning method described later. Indicates.
The cleaning method is not particularly limited as long as it is a method that can be adopted when cleaning the semiconductor device substrate. Among them, the method of contacting the cleaning liquid with the substrate is a spin type in which the substrate is rotated at a high speed while flowing the cleaning liquid over the substrate, and the liquid temperature of the cleaning liquid is preferably in the range of room temperature to 90 ° C. because stable results can be obtained. .

Further, at the time of cleaning, a cleaning method using physical force,
For example, mechanical cleaning such as scrubbing using a cleaning brush, ultrasonic cleaning in which a substrate is irradiated with ultrasonic waves having a frequency of 0.5 MHz or more, and cleaning methods using these in combination make it more stable. It is preferable because the washing result can be obtained.

The cleaning method of the present invention is performed by directly contacting the cleaning liquid with the substrate. The method of contacting the cleaning liquid with the substrate is a dip type in which the cleaning liquid is filled in a cleaning tank to immerse the substrate, a spin type in which the substrate is rotated at a high speed while flowing the cleaning liquid over the substrate from a nozzle, and the liquid is sprayed onto the substrate for cleaning. A spray type etc. are mentioned. As an apparatus for performing such cleaning, there are a batch type cleaning apparatus for simultaneously cleaning a plurality of substrates contained in a cassette, a single wafer cleaning apparatus for mounting one substrate on a holder and cleaning the same. .

The cleaning time is usually 30 seconds to 30 minutes, preferably 1 to 15 minutes in the case of a batch type cleaning apparatus, and usually 1 second to 15 minutes, preferably 5 seconds to 5 minutes in the single wafer cleaning apparatus. Is. If the cleaning time is too short, the cleaning effect is not sufficient, and if it is too long, the improvement of the cleaning effect is small,
This causes a decrease in throughput. The cleaning liquid of the present invention can be applied to any of the above-mentioned methods, but is preferably used for spin-type or spray-type cleaning because it enables more efficient decontamination in a short time. Then, if it is applied to a single-wafer cleaning apparatus in which the reduction of the cleaning time and the reduction of the amount of cleaning liquid used are problems, these problems are solved, which is preferable.

The temperature of the cleaning liquid is usually room temperature,
For the purpose of improving the cleaning effect, it is preferable to heat to about 40 to 70 ° C. Further, when cleaning a substrate having exposed silicon on the surface, organic substances are likely to remain on the silicon surface. Therefore, the substrate is subjected to a heat treatment step at a temperature of 300 ° C. or higher for thermal decomposition, or ozone water is used. It is preferable to oxidatively decompose the organic matter by the treatment.

The cleaning method of the present invention is preferably used in combination with a cleaning method by physical force, for example, mechanical cleaning such as scrub cleaning using a cleaning brush or ultrasonic cleaning. In particular, it is preferable to use ultrasonic irradiation or brush scrub together because the removal property of particle contamination is further improved and the cleaning time is shortened. In particular, it is preferable to use a resin brush for cleaning after CMP.

The material of the resin brush can be selected arbitrarily, but it is preferable to use PVA (polyvinyl alcohol), for example. Further, it is preferable to irradiate the substrate with ultrasonic waves having a frequency of 0.5 MHz or more, because the synergistic action with the surfactant significantly improves the particle removability. Furthermore, before and / or after the cleaning method of the present invention, cleaning with electrolytic ion water obtained by electrolysis of water or hydrogen water in which hydrogen gas is dissolved in water may be combined.

[0091]

EXAMPLES Next, the present invention will be specifically described by way of examples, but the present invention is not limited to the following examples unless it exceeds the gist.

Examples 1 and 2 and Comparative Examples 1 to 3 (Evaluation of Cleanability of Particle Contamination by Scrub Cleaning) 8-inch silicon substrate with low dielectric constant film (SiOC: carbon-containing SiO ₂ ) (radius r is 4 inches) The disc-shaped substrate (1) was immersed in the SiO ₂ slurry solution for 10 minutes. The substrate after the immersion was washed with ultrapure water for 1 minute, and spin-dried with a multi-spinner (“KSSP-201” manufactured by Kaijo Corporation). After that, the number of fine particles adhering to the substrate surface was measured by a laser surface inspection device (“LS-5000” manufactured by Hitachi Electronics Engineering Co., Ltd.), and a certain number of SiO ₂ particles of 0.2 μm or more (however, the upper limit was 1000
It was confirmed that they were attached.

Using the cleaning liquids shown in Table 1, the above-mentioned multi-spinner was used to brush the above-mentioned SiO ₂ with a brush made of PVA.
The particle-attached substrate was brush scrubbed to remove particles. The washing with the washing solution was performed at room temperature for 1 minute.
Then, the substrate was washed with ultrapure water for 1 minute and then spin-dried to obtain a washed substrate. The results are shown in Table 1.

[0094]

[Table 1]

Examples 3 to 6 and Comparative Examples 4 to 8 (Evaluation of Cleanability of Particle Contamination by Scrub Cleaning) First, a SiO ₂ particle-attached substrate was prepared in the same manner as in Example 1. Then, using a washing liquid shown in Table 2, the cleaning time except for using inter 0.5 minutes, in the same manner as in Example 1 SiO ₂
The particle-attached substrate was washed to obtain a washed substrate. The results are shown in Table 2.
Shown in.

The wettability evaluation in Table 2 was performed by the following method.
That is, a low dielectric constant film (SiOC: carbon-containing SiO ₂ )
Test pieces (2 cm square) marked with are soaked vertically in each of the cleaning solutions shown in Table 2. After 0.5 minutes, the test piece was pulled out vertically and evaluated by the ratio of the area with the cleaning liquid to the total area of the test piece. The evaluation criteria are ◯: 80% or more, △: 50
% To less than 80%, x: less than 50%.

[0097]

[Table 2]

Examples 7 to 10 (Evaluation of Cleanability of Particle Contamination by Scrub Cleaning) 8-inch silicon substrate with a low dielectric constant film (SiOC: carbon-containing SiO ₂ ) (disk-shaped substrate with radius r of 4 inches) Was surface treated with 0.5 wt% hydrofluoric acid for 1 minute,
It was immersed in the SiO ₂ slurry solution for 10 minutes. After the immersion, wash the substrate with ultrapure water for 1 minute, then use Multi Spinner
It was spin dried with "KSSP-201" manufactured by Kaijo. After that, the number of fine particles adhering to the substrate surface was measured with a laser surface inspection device (“LS-6600” manufactured by Hitachi Electronics Engineering Co., Ltd.), and a certain number or more of SiO ₂ particles of 0.11 μm or more (however, the upper limit is 100,000). It was confirmed that they were attached.

Using the cleaning liquids shown in Table 3, the above-mentioned multi-spinner was used to remove the above-mentioned SiO ₂ with a PVA brush.
The particle-attached substrate was brush scrubbed to remove particles. The cleaning with the cleaning solution was performed at room temperature for 0.5 minutes. Then, the substrate was washed with ultrapure water for 1 minute and then spin-dried to obtain a washed substrate. The results are shown in Table 3.

[0100]

[Table 3]

Examples 11 and 12 and Comparative Example 9 (Evaluation of Cleanability of Particle Contamination by Scrub Cleaning) First, a SiO ₂ particle-attached substrate was prepared in the same manner as in Example 1. Then, using the cleaning liquid shown in Table 4, except that the cleaning time was 0.5 minutes, SiO ₂ was the same as in Example 1.
The particle-attached substrate was washed to obtain a washed substrate. The results are shown in Table 4.
Shown in.

[0102]

[Table 4]

Example 13 and Comparative Example 10 A 4-inch silicon substrate (a disk-shaped substrate having a radius r of 2 inches) having a thermal oxide film with a thickness of about 100 nm on the surface of the substrate was exposed to the atmosphere for 3 hours and exposed to air. A medium suspension was attached. Substrate surface inspection device ("LS-5" manufactured by Hitachi Electronics Engineering Co., Ltd.
000 ”), the substrate has 10,000 or more particles with a particle size of 0.2 μm or more (however, the upper limit is 100).
(000 pieces) were attached. This substrate was immersed in each cleaning solution shown in Table 3 whose temperature was controlled at 50 ° C. for 10 minutes, washed with running pure water for 10 minutes, and dried by a spin dryer. Table 5 shows the measurement results of the number of particles remaining on the substrate after the cleaning treatment.

Comparative Example 11 A cleaning liquid in Example 13 was prepared by mixing 29% by weight aqueous ammonium hydroxide solution, 50% by weight aqueous hydrogen peroxide and ultrapure water at a volume ratio of 1: 4: 20. Solution (AP
Evaluation was performed in the same manner as in Example 13 except that M cleaning solution) was used. The results are shown in Table 5.

The cleaning liquid of Comparative Example 11 has a relatively small number of adhered particles after cleaning, but since the cleaning liquid contains hydrogen peroxide, it cannot be applied to new materials in the future and cannot be used in the future. Becomes

[0106]

[Table 5]

Example 14 and Comparative Examples 12 to 14 A 4-inch silicon substrate provided with a natural oxide film (having a radius r of 2)
Inch disk-shaped substrate) was immersed in a 0.5 wt% HF aqueous solution for 5 minutes to obtain a substrate from which the surface oxide film was removed. This is the Silicon (IV) Nitride particle ("S" manufactured by Johnson Matthey).
tk # 12145 ") 0.02 g / L was added and immersed in each cleaning solution shown in Table 4 whose temperature was controlled at 50 ° C for 10 minutes, and then washed with running pure water for 5 minutes with a spin dryer. Dried. A substrate surface inspection device (“LS-5000” manufactured by Hitachi Electronics Engineering Co., Ltd.) was used to measure the number of particles having a particle size of 0.2 μm or more remaining on the substrate after the cleaning treatment. The results are shown in Table 6.

[0108]

[Table 6]

Example 15 and Comparative Examples 15 and 16 A 4-inch silicon substrate from which a surface natural oxide film was removed by immersion in a 0.5 wt% HF aqueous solution for 5 minutes (a disk-shaped substrate having a radius r of 2 inches) Prepared. This was immersed in the cleaning liquid of each temperature controlled shown in Table 5 for a predetermined time, washed with running pure water for 5 minutes, and dried by a spin dryer. Immediately after the substrate was dried, the standard deviation Rms (nm) of the Z-axis displacement on the substrate surface was measured with an atomic force microscope (Nano Scope IIIa manufactured by Digital &nbsp; Instruments). The results are shown in Table 7.

The surface roughness of the above substrate is visually evaluated. The following results were obtained. That is, Comparative Example 15
In the cases of Nos. 16 and 16, countless crater-like irregularities having a diameter of about 1 to 10 mm and surface roughness such as interference fringes over the entire surface of the substrate were observed, but in Example 15, it was not observed. .

[0111]

[Table 7]

Examples 16 to 19 and Comparative Examples 17 to 19 Test pieces of polycrystalline polysilicon having a film thickness of about 100 nm were prepared by removing the surface oxide film by immersion in a 0.5 wt% HF aqueous solution for 5 minutes. . This test piece is 50 ℃
After immersion treatment for 10 minutes in each cleaning solution whose temperature was controlled in Table 6, the sample was washed with running pure water for 5 minutes and dried by nitrogen blowing. The film thickness of the polycrystalline polysilicon was measured by an optical interference type film thickness meter (“Nanospec L-6100” manufactured by Nanometrics Co., Ltd.). The etching rate was calculated by measuring the film thickness before and after the cleaning treatment. The results are shown in Table 8.

[0113]

[Table 8]

Example 20, Reference Example 1 A test piece of tungsten having a film thickness of about 100 nm was prepared by removing the surface oxide film by immersing in a 0.3% by weight aqueous ammonia solution for 5 minutes. 40 pieces of this test piece
Immersion treatment was performed for 10 minutes in each of the cleaning solutions shown in Table 9 whose temperature was controlled at 0 ° C., followed by washing with running deionized water for 5 minutes, and drying with nitrogen blow. The film thickness of tungsten was derived by conversion from reflection intensity using total reflection fluorescent X-ray ("RIX-3000" manufactured by Jeol Co.). The etching rate was calculated by measuring the film thickness before and after the cleaning treatment. The results are shown in Table 9.

Here, as is clear from comparison between Example 20 and Reference Example 1, the cleaning liquid of the present invention suppresses the etching rate of the substrate surface with respect to a simple alkaline aqueous solution,
It can be seen that it is excellent as a substrate device cleaning liquid for semiconductor devices.

Comparative Example 20 Evaluation was carried out in the same manner as in Example 20, except that the same APM cleaning liquid as in Comparative Example 11 was used as the cleaning liquid in Example 20. The results are shown in Table 9.

[0117]

[Table 9]

Example 21, Comparative Example 21 A 4-inch silicon substrate (a disk-shaped substrate having a radius r of 2 inches) was immersed in an APM cleaning liquid containing metal ions (Fe, Cu). This APM cleaning solution was prepared by mixing 29% by weight aqueous ammonia, 31% by weight aqueous hydrogen peroxide and water at a volume ratio of 1: 1: 5, and a metal content of Fe (20 p).
pb) and Cu (1 ppm) were prepared by adding a metal ion-containing aqueous solution. The soaked silicon substrate was washed with ultrapure water for 10 minutes and dried by nitrogen blowing to obtain a silicon substrate contaminated with metal.

Contaminating metals (Fe, C) on this silicon substrate
The analysis of u) was performed on the contaminated silicon substrate and the cleaned silicon substrate by the following method. That is, the metal on the surface of the substrate is recovered by treating the substrate with an aqueous solution containing 0.1% by weight of hydrofluoric acid and 1% by weight of hydrogen peroxide, and the amount of metal is measured by an inductively coupled plasma mass spectrometer (ICP-MS). Of the metal concentration on the substrate surface (atoms /
cm ² ).

For cleaning the above-mentioned silicon substrate contaminated with metal, the cleaning liquid shown in Table 10 was used, and the cleaning liquid temperature was 60.
C., the washing time was 10 minutes, and the dip washing method was used. Table 10 shows the analysis results of the contaminated silicon substrate and the residual metals (Fe, Cu) on the surface of the cleaned silicon substrate.

[0121]

[Table 10]

From the above results, the cleaning liquid of the present invention was found to have fine particles (particles) attached to the hydrophobic low dielectric constant film.
It is clear that the removability of Further, it can be seen that, as compared with the conventional cleaning method using an ammonium hydroxide solution or an APM solution, it has more excellent removability with respect to particle adhered substances derived from airborne substances.

Similarly, even if fine particles (particles) enter the system, they can be prevented from adhering to the substrate by removing them by the cleaning method of the present invention. Furthermore,
Compared with the conventional cleaning method, it is possible to suppress the roughness of the silicon surface (surface roughness) to an extremely small level even with an alkaline cleaning solution, and there are almost no side effects such as changes in processing dimensions due to etching on polysilicon or tungsten. Therefore, it is possible to achieve both the cleaning property, the roughness suppression, and the low etching property.

The cleaning liquid of the present invention can be used in both the pre-process and the post-process even if it is a semiconductor device substrate having a material having a low resistance to a chemical liquid such as hydrogen peroxide on its surface. It is obvious that the cleaning liquid has an excellent cleaning effect.

[0125]

According to the cleaning liquid of the present invention, a semiconductor material such as silicon, an insulating material such as silicon nitride, silicon oxide, glass, a low dielectric constant material, a transition metal or a transition metal compound is partially or entirely surfaced. In the substrate for semiconductor devices, which is described in 1., it is possible to effectively remove fine particles (particles), organic contamination, and metal contamination attached to the surface of the substrate by cleaning, and it is possible to suppress adhesion even when fine particles and the like enter the system. is there. In particular, it improves the wettability of a hydrophobic low dielectric constant material that easily repels chemicals and excels in detergency. Further, even in an alkaline cleaning liquid, it is possible to achieve both the suppression of the roughness of the silicon surface and the low etching property in addition to the cleaning property, and a surface treatment method such as for cleaning contaminants in the manufacturing process of semiconductor devices, display devices, etc. As, it is very useful industrially.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C11D 3/04 C11D 3/04 3/20 3/20 3/30 3/30 3/34 3/34 ( 72) Inventor Hitoshi Morinaga 1-1-1 Kurosaki Shiroishi, Hachimansai-ku, Kitakyushu City, Fukuoka Prefecture Mitsubishi Chemical Corporation F-term (reference) 4H003 AC07 BA12 DA15 DC04 EA23 EB08 EB13 EB19 EB22 ED02 FA07 FA28

Claims (21)

[Claims] 1. At least the following components (A) and (B):
And (C) are contained, The cleaning liquid of the semiconductor device substrate characterized by the above-mentioned. Component (A): having a hydrocarbon group which may have a substituent (excluding phenyl group) and a polyoxyethylene group, and having a carbon number (m) in the hydrocarbon group and a polyoxyethylene group The ratio (m / n) of the number of oxyethylene groups (n) is 1 to 1.
An ethylene oxide type surfactant having 5 and having 9 or more carbon atoms (m) and 7 or more oxyethylene groups (n). Component (B): Water Component (C): Alkali or organic acid 2. The carbon number (m) in the component (A) is 9 to.
16. The cleaning liquid according to claim 1, which is 16. 3. An alkali containing as a component (C), p
The cleaning liquid according to claim 1 or 2, wherein H is 9 or more. 4. The cleaning liquid according to claim 3, wherein the component (C) is an alkali compound represented by the following general formula (I). Embedded image (R ¹ ) ₄ N ⁺ OH ⁻ (I) (wherein R ¹ is a hydrogen atom, a hydroxyl group, an alkoxy group,
Indicates an alkyl group which may be substituted with halogen,
R ¹ may be the same or different. ) 5. The cleaning liquid according to claim 4, wherein the component (C) is ammonium hydroxide or quaternary ammonium hydroxide having an alkyl group having 1 to 4 carbon atoms and / or a hydroxyalkyl group. 6. An organic acid as component (C), which has a pH of
Is 1-5, The cleaning liquid of Claim 1 or 2. 7. The cleaning liquid according to claim 6, wherein the component (C) is an organic carboxylic acid and / or an organic sulfonic acid. 8. The cleaning liquid according to claim 7, wherein the organic carboxylic acid is at least one selected from the group consisting of acetic acid, propionic acid, oxalic acid, succinic acid, malonic acid, citric acid, tartaric acid, and malic acid. 9. The organic sulfonic acid is methanesulfonic acid,
The cleaning liquid according to claim 7, which is at least one selected from the group consisting of ethanesulfonic acid, n-propanesulfonic acid, i-propanesulfonic acid, and n-butanesulfonic acid. 10. The content of component (A) is from 0.0001 to
The cleaning liquid according to claim 1, which is 1% by weight. 11. The cleaning liquid according to claim 1, wherein the component (A) is a polyoxyethylene alkyl ether. 12. The cleaning liquid according to claim 1, further containing a complexing agent. 13. The cleaning liquid according to claim 1, which contains substantially no hydrogen peroxide. 14. A method of cleaning a semiconductor device substrate, which comprises using the cleaning liquid according to claim 1. 15. The cleaning method according to claim 14, wherein the substrate is cleaned while irradiating an ultrasonic wave having a frequency of 0.5 MHz or more. 16. The cleaning method according to claim 14, wherein the semiconductor device substrate after chemical mechanical polishing is brush-cleaned. 17. The cleaning method according to claim 14, wherein the cleaning liquid is heated to a temperature of 40 to 70 ° C. before use. 18. After washing with a washing liquid, the temperature is further 300 ° C.
The cleaning method according to claim 14, wherein the heat treatment or the ozone water treatment is performed. 19. The cleaning method according to claim 14, which is applied to a semiconductor device substrate having an insulating film having a contact angle of water of 60 ° or more on its surface. 20. The cleaning method according to claim 14, which is applied to a semiconductor device substrate having silicon, a transition metal, or a transition metal compound on its surface. 21. A semiconductor device substrate cleaning liquid having at least a semiconductor element electrode or a metal wiring on the surface, which satisfies the following conditions (a), (b) and (c): (A) Substantially does not corrode semiconductor element electrodes and metal wiring. (B) The amount of contaminating metal is 1000 to 5000 (× 10 ¹⁰ a
In the case of cleaning a substrate having a thickness of 10 (toms / cm ² ), the amount of contaminated metal after cleaning is 10 (× 10 ¹⁰ atoms)
/ Cm ² ) or less. (C) Particles having a particle size of 0.1 μm or more
In the case where a substantially circular substrate surface having a radius r of 100,000 (pieces / 0.03 m ² ) is washed for t (minutes), particles in a circle on the substrate surface having the same center as the substrate after cleaning When the number is t = 0.5 to 1, the circumference radius is 0.
It is 200 / t or less within the circumference of 6r, or 800 / t or less within the circumference of a radius of 0.9r.