WO2018079675A1

WO2018079675A1 - Rinsing agent composition for silicon wafers

Info

Publication number: WO2018079675A1
Application number: PCT/JP2017/038767
Authority: WO
Inventors: 内田洋平
Original assignee: 花王株式会社
Priority date: 2016-10-28
Filing date: 2017-10-26
Publication date: 2018-05-03
Also published as: KR102370806B1; KR20190075897A

Abstract

The rinsing agent composition for silicon wafers according to the present invention comprises a water-soluble polymer and water, wherein the water-soluble polymer exhibits a difference (Z-Z₀) of 25 mV or less between the zeta potential Z of a water-soluble polymer-containing silica aqueous dispersion (aqueous dispersion S) that comprises the water-soluble polymer, silica particles, water, and if necessary, hydrochloric acid or ammonia, and that has a water-soluble polymer concentration of 0.1 mass%, a silica particle concentration of 0.1 mass%, and a pH of 7.0 at 25°C, and the zeta potential Z₀ of a silica aqueous dispersion (aqueous dispersion S₀) that comprises silica particles, water, and if necessary, hydrochloric acid or ammonia, and that has a silica particle concentration of 0.1 mass% and a pH of 7.0 at 25°C.

Description

Rinsing agent composition for silicon wafer

The present invention relates to a rinsing agent composition for silicon wafers, a rinsing method for silicon wafers using the same, a method for producing silicon wafers, and a method for producing semiconductor substrates.

In recent years, the design rule of semiconductor devices has been miniaturized due to the increasing demand for higher recording capacity of semiconductor memories. For this reason, the depth of focus becomes shallow in the photolithography performed in the manufacturing process of the semiconductor device, and the demand for reduction of surface defects (LPD: Light point defects) and surface roughness (Haze) of the silicon wafer (bare wafer) becomes more severe. It has become.

In order to improve the quality of the silicon wafer, the polishing process for polishing the silicon wafer includes a lapping (rough polishing) process for planarizing the silicon wafer obtained by slicing a silicon single crystal ingot into a thin disk shape. There is a final polishing process in which the surface of the silicon wafer is mirror-finished after etching the lapped silicon wafer. In particular, the final polishing performed at the final stage of polishing is performed for the purpose of suppressing haze and suppressing LPD such as particles, scratches and pits by improving wettability (hydrophilization) of the polished silicon wafer surface. Yes.

As a polishing liquid composition used for polishing a silicon wafer, a polishing liquid composition containing silica particles, hydroxyethyl cellulose (HEC), polyethylene oxide, and an alkali compound is disclosed for the purpose of improving the haze level. (Patent Document 1). In order to achieve both reduction in surface roughness (haze) and reduction in surface defects (LPD), the ratio of the number of oxygen atoms derived from hydroxyl groups to the number of oxygen atoms derived from polyoxyalkylenes (number of oxygen atoms derived from hydroxyl groups / A polishing composition for silicon wafers containing a water-soluble polymer having a value within a predetermined range of the number of oxygen atoms derived from polyoxyalkylene has been disclosed (Patent Document 2). In a solution having a pH of 2.0 or more and a polyvinyl alcohol resin having a 1,2-diol structure in the side chain for the purpose of reducing contamination of the polished workpiece surface while suppressing aggregation of abrasive grains. And a polishing composition for silicon wafers, which contains abrasive grains whose surface is chemically modified so that the surface zeta potential is negative and has no isoelectric point (Patent Document 3). A polishing composition for silicon wafers containing hydroxypropylmethylcellulose and having a negative zeta potential in the polishing liquid composition has been disclosed for the purpose of suppressing a decrease in smoothness and reducing the number of defects. (Patent Document 4). It is not a polishing composition, nor is it used for the silicon wafer surface, but it can remove contaminants on the semiconductor device substrate surface after the CMP process and clean the substrate surface in a short time. The purpose is to contain polyvinyl pyrrolidone and polyethylene oxide-polypropylene oxide block copolymer as a polymer flocculant, and increase the particle size of the fine particles by aggregation, while making the fine particles have a negative zeta potential, and fine particles on the surface of the semiconductor device substrate. A substrate cleaning solution for a semiconductor device that suppresses adhesion of the semiconductor is disclosed (Patent Document 5).

JP 2004-128089 A WO2015 / 060293 WO2014 / 084091 JP 2014-154707 A JP 2012-94852 A

Under alkaline conditions, both the surface charge of the silica particles and the silicon wafer are negatively charged, and due to the repulsion of the charges, the silica particles cannot approach the silicon wafer and the polishing rate cannot be fully expressed, but they are contained in the polishing composition. Since the polymer is adsorbed on both the surface of the silicon wafer and the silica particles, it suppresses the charge repulsion between the silicon wafer and the silica particles, develops the binder effect, and contributes to the improvement of the polishing rate of the silicon wafer. .

However, since the polymer adheres to the surface of the silicon wafer polished in the polishing process (hereinafter also referred to as “the polished silicon wafer”), for example, water is supplied between the polished silicon wafer and the pad. In addition, even when the so-called water rinse is performed in which the pad is moved relative to the silicon wafer after polishing while the silicon wafer and the pad are in contact with each other, silica particles are reattached to the surface of the silicon wafer. After the polishing, it took a considerable amount of time to clean the silicon wafer, which hindered improvement in productivity and cost reduction.

Accordingly, in the present invention, a rinsing agent composition for a silicon wafer, a silicon wafer rinsing method using the same, a silicon wafer rinsing method, a silicon wafer manufacturing method, A method for manufacturing a semiconductor substrate is provided.

The rinse composition for a silicon wafer of the present invention is a rinse composition for a silicon wafer containing a water-soluble polymer and an aqueous medium,
The water-soluble polymer is
It consists of the water-soluble polymer, silica particles, water, and hydrochloric acid or ammonia as necessary. The concentration of the water-soluble polymer is 0.1% by mass, the concentration of the silica particles is 0.1% by mass, 25 ° C. Zeta potential Z of water-soluble polymer-containing silica aqueous dispersion (aqueous dispersion S) having a pH of 7.0, silica particles, water, and optionally hydrochloric acid or ammonia, and the concentration of the silica particles is 0.1 wt%, 25 aqueous silica dispersion of pH at ℃ 7.0 difference (Z-Z ₀₎ between the zeta potential Z ₀ of the (aqueous dispersion S ₀₎ is a water-soluble polymer which becomes less 25mV It is the rinse agent composition for silicon wafers.

The rinse composition for a silicon wafer of the present invention is a rinse composition for a silicon wafer containing a water-soluble polymer and an aqueous medium,
The rinse composition for silicon wafers, wherein the water-soluble polymer contains at least one selected from the group consisting of polyglycerin, polyglycerin derivatives, polyglycidol, polyglycidol derivatives, polyvinyl alcohol derivatives, and polyacrylamide.

The method for rinsing a silicon wafer according to the present invention includes a step of rinsing a polished silicon wafer using the rinse agent composition for a silicon wafer according to the present invention.

In the method for producing a silicon wafer of the present invention, the water-soluble polymer contained in the rinse composition for a silicon wafer of the present invention is referred to as a water-soluble polymer A.
A polishing step of polishing a silicon wafer to be polished using a polishing liquid composition containing silica particles, a water-soluble polymer B, a nitrogen-containing basic compound, and an aqueous medium;
A rinsing step of rinsing the polished silicon wafer with the rinse agent composition of the present invention;
Cleaning the rinsed silicon wafer.
The water-soluble polymer A and the water-soluble polymer B may be the same or different.

The method for producing a semiconductor substrate of the present invention includes a step of rinsing a polished silicon wafer using the rinse agent composition for a silicon wafer of the present invention.

The semiconductor substrate manufacturing method of the present invention includes a process of manufacturing a silicon wafer by the silicon wafer manufacturing method of the present invention.

INDUSTRIAL APPLICABILITY According to the present invention, a rinsing agent composition for a silicon wafer and a rinsing method for a silicon wafer using the rinsing agent composition for a silicon wafer, which can shorten the cleaning time of the silicon wafer after polishing and reduce the LPD. The present invention relates to a method for manufacturing a silicon wafer and a method for manufacturing a semiconductor substrate.

In the present invention, the rinsing agent composition for silicon wafer (hereinafter sometimes abbreviated as “rinsing agent composition”) is the water-soluble polymer, silica particles, and water as the specific water-soluble polymer. Accordingly, the water-soluble polymer-containing silica is composed of hydrochloric acid or ammonia, the water-soluble polymer concentration is 0.1% by mass, the silica particle concentration is 0.1% by mass, and the pH at 25 ° C. is 7.0. It consists of zeta potential Z of the aqueous dispersion (aqueous dispersion S), silica particles, water, and hydrochloric acid or ammonia as necessary. The concentration of the silica particles is 0.1% by mass, and the pH at 25 ° C. is 7. A water-soluble polymer (hereinafter referred to as “water-soluble polymer A”) having a property that the difference (Z−Z ₀ ) between the _zero aqueous silica dispersion (aqueous dispersion S ₀ ) and the zeta potential Z ₀ is 25 mV or less. In some cases, including silicon after polishing To enable shortening and LPD reduction in cleaning time Eha, based on the finding that.

When the rinsed silicon wafer is rinsed with the rinse agent composition of the present invention, the mechanism of manifestation of the effect of the present invention that the LPD of the polished silicon wafer can be reduced and the cleaning time can be shortened. Estimated as follows.

When the rinsing agent composition of the present invention is supplied and the rinsing process using the rinsing agent composition is started, the physical force when the pad is moved relative to the silicon wafer after polishing, The water-soluble polymer B, which is a constituent component of the polishing liquid composition adsorbed on the surface of the silica particles, is replaced with the water-soluble polymer A. Then, since the reattachment of the silica particles to the silicon wafer surface after polishing is suppressed, the residual amount of silica particles on the polished silicon wafer subjected to the cleaning process can be remarkably reduced. Even when the functional polymer A is adsorbed to the silica particles, the zeta potential of the silica particles is not greatly changed, and the zeta potential of the silica particles can be maintained at a negative large value, so that aggregation of the silica particles is also suppressed. Therefore, it is presumed that the rinse agent composition of the present invention contains the water-soluble polymer A, so that the reduction of LPD and the cleaning time of the polished silicon wafer are realized.

[Rinse composition]
The rinse agent composition of the present invention includes a water-soluble polymer A, an aqueous medium, and optional components as long as the effects of the present invention are not hindered. Details of the optional component will be described later.

[Water-soluble polymer A]
The water-soluble polymer A is a water-soluble polymer having such a property that the difference (Z−Z ₀ ) between the zeta potential Z of the aqueous dispersion S and the zeta potential Z ₀ of the aqueous dispersion S ₀ is 25 mV or less. . Here, the aqueous dispersion S is composed of a water-soluble polymer A, silica particles, water, and hydrochloric acid or ammonia as required. The concentration of the water-soluble polymer A is 0.1% by mass, and the concentration of silica particles is A water-soluble polymer-containing silica aqueous dispersion having a pH of 7.0% by mass and 25 ° C. is 7.0. The aqueous dispersion S ₀ is a silica aqueous dispersion comprising silica particles, water, and optionally hydrochloric acid or ammonia, and having a silica particle concentration of 0.1 mass% and a pH of 7.0 at 25 ° C. . The zeta potential can be measured by the method described in the examples. When the water-soluble polymer A is composed of two or more water-soluble polymers, a mixture of two or more water-soluble polymers has a property that the difference (ZZ ₀ ) is 25 mV or less. When the water-soluble polymer A is a mixture of two or more water-soluble polymers, “the concentration of the water-soluble polymer A is 0.1% by mass” means that the mixture in the aqueous dispersion S This means that the total concentration of each water-soluble polymer in the aqueous dispersion S is 0.1% by mass.

When the water-soluble polymer A comprises only the water-soluble polymer a1 described later, the difference (Z−Z ₀ ) is 25 mV or less, preferably 15 mV or less, more preferably from the viewpoint of suppressing aggregation of silica particles. 9 mV or less, more preferably 7 mV or less.

When the water-soluble polymer A is a mixture of a water-soluble polymer a1 and a water-soluble polymer a2 described later, the difference (Z−Z ₀ ) is 25 mV or less from the viewpoint of suppressing aggregation of silica particles. Preferably it is 15 mV or less, More preferably, it is 12 mV or less, More preferably, it is 9 mV or less.

The zeta potential Z ₀ of the aqueous dispersion S ₀ is, for example, a predetermined value within a range of −40 mV to −50 mV, and is adjusted using a silica stock solution (“PL-3” manufactured by Fuso Chemical Co., Ltd.) as an example. The zeta potential of the prepared aqueous dispersion S ₀ (for example, −46 mV).

When the water-soluble polymer A is composed only of the water-soluble polymer a1 described later, the water-soluble polymer A is a secondary particle size of the silica particles in the aqueous dispersion S from the viewpoint of suppressing aggregation of the silica particles. The ratio (d / d ₀ ) of d to the secondary particle size d ₀ of the silica particles in the aqueous dispersion S ₀ is preferably 1.35 or less, more preferably 1.17 or less, and still more preferably 1 .10 or less, still more preferably 1.08 or less, and from the viewpoint of LPD reduction, preferably 1.00 or more, more preferably 1.02 or more, and still more preferably 1.04. As described above, the water-soluble polymer is more preferably 1.05 or more.

When the water-soluble polymer A is a mixture of a water-soluble polymer a1 to be described later and a water-soluble polymer a2 to be described later, the water-soluble polymer A is the aqueous dispersion from the viewpoint of suppressing aggregation of silica particles. a secondary particle diameter d of the silica particles in S, the ratio of the secondary particle diameter d ₀ of the silica particles of the aqueous dispersion S in ₀ (d / d ₀₎ is preferably 1.35 or less, more preferably Is a water-soluble polymer having a value of 1.34 or less, more preferably 1.33 or less, and even more preferably 1.32 or less, and preferably from 1.00 or more, more preferably 1 from the viewpoint of reducing LPD. .25 or more, more preferably 1.30 or more, and even more preferably 1.31 or more.

The secondary particle diameter d ₀ of the silica particles in the aqueous dispersion S ₀ is, for example, a predetermined value within the range of 64 to 73 nm, preferably a predetermined value within the range of 66 to 69 nm. This is the secondary particle size (for example, 68.4 nm) of silica particles in the aqueous dispersion S ₀ containing a silica stock solution (“PL-3” manufactured by Fuso Chemical Co., Ltd.) as a silica particle supply source.

The content of the water-soluble polymer A in the rinse agent composition is preferably 0.001% by mass or more, more preferably 0.015% by mass or more, and still more preferably from the viewpoint of shortening the washing time and reducing the LPD. 0.020% by mass or more, still more preferably 0.025% by mass or more, still more preferably 0.03% by mass or more, and from the same viewpoint, preferably 1.0% by mass or less, more preferably It is 0.7 mass% or less, More preferably, it is 0.4 mass% or less, More preferably, it is 0.1 mass% or less, More preferably, it is 0.08 mass% or less.

The water-soluble polymer A is preferably at least selected from the group consisting of polyglycerin, polyglycerin derivatives, polyglycidol, polyglycidol derivatives, polyvinyl alcohol derivatives, and polyacrylamide from the viewpoint of shortening the washing time and reducing LPD. One type of water-soluble polymer a1.

As the polyglycerin derivative, those in which a functional group is added to polyglycerin with an ether bond or an ester bond are preferable, and those with an ether bond are more preferable.

The polyglycerin derivative is preferably polyglycerin alkyl ether, polyglycerin dialkyl ether, polyglycerin fatty acid ester, polyethylene oxide-added polyglycerin, polypropylene oxide-added polyglycerin, amino, from the viewpoint of shortening the washing time and reducing the LPD. Polyglycerol, etc., more preferably polyglycerol alkyl ether. These may be used alone or in combination of two or more.

The polyglycidol derivative is preferably a polyglycidol alkyl ether, a polyglycidol dialkyl ether, a polyglycidol fatty acid ester, a polyethylene oxide-added polyglycidol, a polypropylene oxide-added polyglycidol, an amino acid, from the viewpoint of shortening the washing time and reducing the LPD. Polyglycidol. These may be used alone or in combination of two or more.

Preferred examples of the polyvinyl alcohol derivative include polyethylene oxide-modified polyvinyl alcohol and sulfonic acid-modified polyvinyl alcohol from the viewpoint of shortening the washing time and reducing the LPD. These may be used alone or in combination of two or more.

Among the above, the water-soluble polymer a1 is preferably polyglycerin, polyglycerin alkyl ether, polyglycerin dialkyl ether, polyglycerin fatty acid ester, polyethylene oxide-modified polyvinyl, from the viewpoints of shortening the washing time and reducing LPD. It is at least one selected from the group consisting of alcohol, sulfonic acid-modified polyvinyl alcohol, and polyacrylamide, more preferably at least one selected from the group consisting of polyglycerin and polyglycerin alkyl ether, and even more preferably. , A polyglycerin alkyl ether. The water-soluble polymer a1 may be used by selecting two or more of them from the above. From the viewpoint of shortening the washing time and reducing the LPD, the rinse agent composition is composed of polyglycerin and polyglycerin alkyl ether. It is preferable that both are included. The number of carbon atoms of the hydrophobic group of the polyglycerol derivative is preferably 6 or more, more preferably 8 or more, and preferably 22 or less, more preferably 18 or less.

When the water-soluble polymer a1 contains polyglycerin and polyglycerin alkyl ether, these mass ratios (polyglycerin / polyglycerin alkyl ether) are preferably 0.5 or more, more preferably, from the viewpoint of reducing LPD. 1.0 or more, more preferably 2.0 or more, and from the same viewpoint, it is preferably 10 or less, more preferably 6.0 or less, and still more preferably 5.0 or less.

The weight average molecular weight of the water-soluble polymer a1 is preferably 500 or more, more preferably 700 or more, still more preferably 900 or more, from the viewpoint of shortening the washing time and LPD, and from the same viewpoint, Preferably it is 1,500,000 or less, more preferably 500,000 or less, still more preferably 100,000 or less, even more preferably 25,000 or less, and even more preferably 10,000 or less. In addition, the weight average molecular weight of water-soluble polymer A can be measured by the method as described in an Example.

The water-soluble polymer a1 is preferably a pentamer or more, more preferably a 10mer or more, still more preferably a 15mer or more, from the viewpoint of shortening the washing time and reducing the LPD, and the same viewpoint. Therefore, it is preferably 5,000 mer or less, more preferably 500 mer or less, still more preferably 200 mer or less, still more preferably 150 mer or less, and even more preferably 100 mer or less.

From the viewpoint of reducing LPD, the water-soluble polymer A is a water-soluble polymer containing the water-soluble polymer a1 and a betaine structure (hereinafter referred to as “water-soluble polymer containing a betaine structure”). And a mixture thereof.

[Water-soluble polymer containing betaine structure]
In the present application, the betaine structure refers to a structure having a positive charge and a negative charge in the same molecule, and the charge is neutralized. The betaine structure preferably has the positive charge and the negative charge at positions not adjacent to each other, and preferably at a position through one or more atoms.

The water-soluble polymer a2 includes a polymer of a monomer containing a betaine structure, a copolymer of a monomer containing a betaine structure and a monomer containing a hydrophobic group, and a betaine structure from the viewpoint of reducing LPD. Copolymer of monomer and monomer containing hydroxyl group, copolymer of monomer containing betaine structure and monomer containing oxyalkylene group, monomer containing betaine structure and monomer containing amino group And at least one water-soluble polymer selected from a copolymer of a monomer and a monomer having a betaine structure and a monomer having a quaternary ammonium group, and a monomer having a betaine structure, A monomer copolymer containing a hydrophobic group is more preferred.

Examples of the betaine structure include sulfobetaine, carbobetaine, phosphobetaine, and the like. From the viewpoint of reducing LPD, carbobetaine and phosphobetaine are more preferable, and phosphobetaine is more preferable.

The structural unit A derived from the monomer containing a betaine structure is preferably a structural unit represented by the following formula (1) from the viewpoint of reducing LPD.

In the formula (1),
R ¹ to R ³ : the same or different, a hydrogen atom, a methyl group, or an ethyl group R ⁴ : an alkylene group having 1 to 4 carbon atoms, or —Y ¹ —OPO ₃ ^— —Y ² —
Y ¹ , Y ² : the same or different, an alkylene group having 1 to 4 carbon atoms R ⁵ , R ⁶ : the same or different, a hydrocarbon group having 1 to 4 carbon atoms X ¹ : O or NR ⁷
R ⁷ : a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms X ² : a hydrocarbon group having 1 to 4 carbon atoms, —R ¹⁷ SO ₃ ⁻ , or —R ¹⁸ COO ⁻
R ¹⁷ and R ^{18 are the} same or different and each represents an alkylene group having 1 to 4 carbon atoms.
X ² is —R ¹⁷ SO ₃ ⁻ or —R ¹⁸ COO ^— when R ⁴ is an alkylene group having 1 to ⁴ carbon atoms, and R ⁴ is —Y ¹ —OPO ₃ ^— —Y ^2. In the case of-, it is a hydrocarbon group having 1 to 4 carbon atoms.

R ¹ and R ² are each preferably a hydrogen atom from the viewpoint of monomer availability, monomer polymerizability, and LPD reduction.

R ³ is preferably a hydrogen atom or a methyl group, and more preferably a methyl group, from the viewpoints of monomer availability, monomer polymerizability, and LPD reduction.

X ¹ is preferably O (oxygen atom) from the viewpoint of monomer availability, monomer polymerizability, and LPD reduction.

R ⁴ is, from the viewpoint of reducing the LPD, alkylene group having 2 or 3 carbon atoms, or -Y ¹ -OPO ₃ ^- -Y ² ^- is preferably an alkylene group having 2 carbon atoms, or -Y ¹ -OPO ₃ ^- -Y ² - is more ^{_{^{^{preferred, -Y 1 -OPO 3 - -Y 2}}}} - is more preferable.

Y ¹ and Y ² are each preferably an alkylene group having 2 or 3 carbon atoms, more preferably an alkylene group having 2 carbon atoms, from the viewpoint of availability of monomers, polymerizability of monomers, and reduction of LPD. .

R ⁵ and R ⁶ are each preferably a methyl group or an ethyl group, and more preferably a methyl group, from the viewpoint of monomer availability, monomer polymerizability, and LPD reduction.

X ² is —R ¹⁷ SO ₃ ⁻ or —R ¹⁸ COO ^— when R ⁴ is an alkylene group having 1 to ⁴ carbon atoms, and —R ¹⁸ COO ^— is preferable from the viewpoint of reducing LPD. X ² is a hydrocarbon group having 1 to 4 carbon atoms when R ⁴ is —Y ¹ —OPO ₃ ^— —Y ² —, and a methyl group is more preferable from the viewpoint of reducing LPD.

The number of carbon atoms of R ¹⁷ is preferably 1 or more and 3 or less, more preferably 2 or more and 3 or less, from the viewpoints of availability of monomers, monomer polymerizability, and LPD reduction. The number of carbon atoms of R ¹⁸ is preferably 1 or more and 3 or less, and more preferably 1 or more and 2 or less, from the viewpoint of availability of unsaturated monomers, monomer polymerization and LPD reduction.

The structural unit A is preferably a structural unit derived from at least one monomer selected from sulfobetaine methacrylate, methacryloyloxyethyl phosphorylcholine, and carboxybetaine methacrylate from the viewpoint of reducing LPD, and methacryloyloxyethyl phosphorylcholine and A structural unit derived from at least one monomer selected from carboxybetaine methacrylate is more preferable, and a structural unit derived from methacryloyloxyethyl phosphorylcholine is more preferable.

The water-soluble polymer a2 is a monomer containing a hydrophobic group, a monomer containing a hydroxyl group, a monomer containing an oxyalkylene group, a monomer containing an amino group, and a monomer containing a quaternary ammonium group. When it is a copolymer of at least one selected monomer (hereinafter sometimes abbreviated as “monomer B”) and a monomer containing a betaine structure, it is derived from monomer B As the structural unit B, for example, the structural unit B represented by the following formula (2) is preferable from the viewpoint of reducing the LPD.

However, in Formula (2),
R ⁸ to R ¹⁰ : the same or different, hydrogen atom, methyl group or ethyl group X ³ : O or NR ¹⁹
R ¹⁹ : a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms R ¹¹ : an alkylene group having 1 to 22 carbon atoms (however, the hydrogen atom of the alkylene group may be substituted with a hydroxyl group) or — (AO) _m — (Where AO is an alkyleneoxy group having 2 to 4 carbon atoms, and m is 1 to 150 in terms of the average number of moles added.)
X ⁴ : hydrogen atom, hydrocarbon group having 1 to 4 carbon atoms (however, the hydrogen atom of the hydrocarbon group may be substituted with a hydroxyl group), hydroxyl group, N ⁺ R ¹² R ¹³ R ¹⁴ or NR ¹⁵ R ¹⁶
R ¹² to R ^{16 are the} same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms.

R ⁸ and R ⁹ are each preferably a hydrogen atom from the viewpoints of availability of monomers, polymerizability of monomers, and reduction of LPD.

R ¹⁰ is preferably a hydrogen atom or a methyl group, and more preferably a methyl group, from the viewpoints of availability of the monomer, polymerizability of the monomer, and reduction of LPD.

X ³ is preferably O from the viewpoint of availability of monomers, polymerizability of monomers, and reduction of LPD.

When X ⁴ is a hydrogen atom, the number of carbon atoms of the alkylene group of R ¹¹ is preferably 3 or more, more preferably 4 or more, from the viewpoints of monomer availability, monomer polymerizability, and LPD reduction. 6 or more are more preferable, 18 or less are preferable, 12 or less are more preferable, and m is preferably 2 or more and 30 or less from the same viewpoint.

When X ⁴ is a hydrocarbon group having 1 to ⁴ carbon atoms, R ¹¹ is preferably — (AO) _m — from the viewpoints of availability of monomers, polymerizability of monomers, and reduction of LPD. The m is preferably 4 or more and 90 or less.

AO is an ethyleneoxy group (EO) which is an alkyleneoxy group having 2 carbon atoms and propylene which is an alkyleneoxy group having 3 carbon atoms from the viewpoint of availability of monomers, polymerizability of monomers and reduction of LPD. It is preferably composed of one or more alkyleneoxy groups selected from oxy groups (PO), more preferably composed of EO. When — (AO) _m — contains two or more alkyleneoxy groups having different carbon numbers, the arrangement of the various alkyleneoxy groups may be block or random, and is preferably a block.

When X ⁴ is a hydroxyl group, N ⁺ R ¹² R ¹³ R ¹⁴ or NR ¹⁵ R ¹⁶ , R ¹¹ has 1 or more carbon atoms from the viewpoints of availability of monomers, polymerizability of monomers and reduction of LPD. An alkylene group of 22 or less (wherein the hydrogen atom of the hydrocarbon group may be substituted with a hydroxyl group) is preferred, and the number of carbon atoms of the alkylene group is preferably 2 or more, and preferably 3 or less, from the same viewpoint. 2 is more preferable.

X ⁴ is preferably a hydrogen atom, a methyl group, a hydroxyl group, or N ⁺ R ¹² R ¹³ R ¹⁴ from the viewpoints of monomer availability, monomer polymerizability, and LPD reduction, and R ¹² to R ¹⁴ Are each preferably a methyl group or an ethyl group, and more preferably a methyl group.

As the structural unit B, a hydrophobic group such as alkyl methacrylate (a hydrogen atom of the hydrophobic group may be substituted with a hydroxyl group) from the viewpoints of availability of monomers, polymerizability of monomers, and reduction of LPD. An unsaturated monomer having a cationic group such as a methacrylate having a quaternary ammonium cation, and an unsaturated monomer having a nonionic group such as a methacrylate having an ethyleneoxy group. A structural unit derived from a seed monomer is preferable, and a structural unit derived from an unsaturated monomer having a hydrophobic group such as alkyl methacrylate (the hydrogen atom of the hydrophobic group may be substituted with a hydroxyl group) is more preferable. preferable.

As the structural unit B, butyl methacrylate (BMA), 2-ethylhexyl methacrylate (EHMA), lauryl methacrylate (LMA), stearyl methacrylate (SMA), methacryloyloxyethyldimethylethylaminium (MOEDES), 2-hydroxy-3 methacrylate -(Trimethylaminio) propyl (THMPA), methacryloylethyltrimethylaminium (MOETMA), methoxypolyethylene glycol methacrylate (MPEGMA), polyethylene glycol methacrylate (PEGMA), methoxypolypropylene glycol methacrylate (MPPGMA), polypropylene glycol methacrylate (PPGMA) and A small amount selected from hydroxyethyl methacrylate (HEMA) Both are more preferable structural units derived from one monomer, BMA, and at least one constituent unit derived from a monomer selected from the LMA more preferable.

(Molar ratio of structural unit A to structural unit B)
The molar ratio of the structural unit A to the structural unit B in the water-soluble polymer a2 (structural unit A / structural unit B) is preferably 10/90 or more, more preferably 20/80 or more, from the viewpoint of reducing LPD. Preferably, it is 30/70 or more, and from the same viewpoint, it is preferably 98/2 or less, more preferably 95/5 or less.

(Structural units other than structural unit A and structural unit B)
The water-soluble polymer a2 may contain a structural unit other than the structural unit A and the structural unit B as long as the effects of the present invention are not impaired. As the structural unit other than the structural unit A and the structural unit B, a structural unit derived from a hydrophobic unsaturated monomer such as styrene is preferable.

The content of structural units other than the structural unit A and the structural unit B in the water-soluble polymer a2 is preferably 1% by mass or less, more preferably 0.5% by mass or less, still more preferably 0.1% by mass or less, More preferably, it is 0.05 mass% or less. The content of structural units other than the structural unit A and the structural unit B in the water-soluble polymer a2 may be 0% by mass.

The total content of the structural unit A and the structural unit B in the water-soluble polymer a2 is preferably 99% by mass or more, more preferably 99.5% by mass or more, still more preferably 99.9% by mass or more, and even more. Preferably it is 99.95 mass% or more, and may be 100 mass%.

From the viewpoint of LPD reduction, the weight average molecular weight of the water-soluble polymer a2 is preferably 10000 or more, more preferably 30,000 or more, still more preferably 50,000 or more, and the water-soluble polymer a2 From the viewpoints of improving solubility and reducing LPD, 1.5 million or less is preferable, 1.2 million or less is more preferable, and 1 million or less is more preferable.

The content of the water-soluble polymer a2 in the rinse agent composition of the present invention is preferably 0.00001% by mass or more, more preferably 0.00005% by mass or more, and 0.0001% by mass or more from the viewpoint of reducing LPD. Is more preferable, and from the viewpoint of LPD reduction, it is preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably 1% by mass or less.

In the rinse agent composition of the present invention, the mass ratio of the water-soluble polymer a1 and the water-soluble polymer a2 (water-soluble polymer a1 / water-soluble polymer a2) is 0.5 or more from the viewpoint of reducing the LPD. Preferably, 1 or more is more preferable, 2 or more is more preferable, and from the viewpoint of LPD reduction, 500 or less is preferable, 200 or less is more preferable, and 100 or less is more preferable.

[Aqueous medium]
Examples of the aqueous medium contained in the rinse agent composition of the present invention include water such as ion-exchanged water and ultrapure water, or a mixed medium of water and a solvent. Examples of the solvent include polyhydric alcohols having 2 to 4 carbon atoms, and glycerin or propylene glycol is preferable. As water in the aqueous medium, ion exchange water or ultrapure water is preferable, and ultrapure water is more preferable. When the aqueous medium is a mixed medium of water and a solvent, the ratio of water to the entire mixed medium is preferably 90% by mass or more, more preferably 92% by mass or more, and further more preferably 95% by mass or more from the viewpoint of economy. preferable.

The content of the aqueous medium in the rinsing agent composition of the present invention is preferably the remainder of the water-soluble polymer A, a basic compound to be described later added as necessary, and other optional components to be described later.

[Optional ingredients (auxiliaries)]
The rinsing agent composition of the present invention is selected from pH adjusters, preservatives, alcohols, chelating agents, anionic surfactants, and nonionic surfactants as long as the effects of the present invention are not hindered. At least one optional component may be included.

[pH adjuster]
Examples of the pH adjuster include basic compounds, acidic compounds, and salts thereof. The salt of the acidic compound is preferably at least one selected from alkali metal salts, ammonium salts, and amine salts, and more preferably ammonium salts. When the basic compound takes a salt form, the counter ion is preferably at least one selected from hydroxide ions, chloride ions and iodide ions, more preferably hydroxide ions and chloride ions. Is at least one selected from

(Basic compound)
Examples of the basic compound include sodium hydroxide, potassium hydroxide, ammonia, ammonium hydroxide, ammonium carbonate, ammonium hydrogen carbonate, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, monoethanolamine, diethanolamine, trimethylamine. Ethanolamine, N-methylethanolamine, N-methyl-N, N-diethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dibutylethanolamine, N- (β- Aminoethyl) ethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, ethylenediamine, hexamethylenediamine, piperazine hexahydrate, anhydrous piperazi 1- (2-aminoethyl) piperazine, N- methylpiperazine, diethylenetriamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide. Two or more of these basic compounds may be used. As the basic compound, ammonia is more preferable from the viewpoint of coexistence of reduction of Haze and LPD of the silicon wafer and improvement of storage stability of the rinse agent composition.

(Acidic compounds)
Examples of the acidic compound include inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid and phosphoric acid, and organic acids such as acetic acid, oxalic acid, succinic acid, glycolic acid, malic acid, citric acid and benzoic acid.

[Preservative]
Preservatives include phenoxyethanol, benzalkonium chloride, benzethonium chloride, 1,2-benzisothiazolin-3-one, (5-chloro-) 2-methyl-4-isothiazolin-3-one, hydrogen peroxide, or A chlorite etc. are mentioned.

[Alcohols]
Examples of alcohols include methanol, ethanol, propanol, butanol, isopropyl alcohol, 2-methyl-2-propanool, ethylene glycol, propylene glycol, polyethylene glycol, glycerin and the like. The content of alcohol in the rinse agent composition of the present invention is preferably 0.01% by mass to 10% by mass.

[Chelating agent]
Examples of chelating agents include 1-hydroxyethane 1,1-diphosphonic acid, ethylenediaminetetraacetic acid, sodium ethylenediaminetetraacetate, nitrilotriacetic acid, sodium nitrilotriacetate, ammonium nitrilotriacetate, hydroxyethylethylenediaminetriacetic acid, hydroxyethylethylenediaminetriacetic acid Examples thereof include sodium, triethylenetetramine hexaacetic acid, sodium triethylenetetramine hexaacetate and the like. The content of the chelating agent in the rinse agent composition of the present invention is preferably 0.001 to 10% by mass.

[Anionic surfactant]
Examples of the anionic surfactant include fatty acid soaps, carboxylates such as alkyl ether carboxylates, sulfonates such as alkylbenzene sulfonates and alkylnaphthalene sulfonates, higher alcohol sulfates, alkyl ether sulfates. And sulfate ester salts such as alkyl phosphate esters and the like.

[Nonionic surfactant]
Nonionic surfactants include polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbit fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl phenyl ether, Examples include polyethylene glycol types such as oxyalkylene (hardened) castor oil, polyhydric alcohol types such as sucrose fatty acid esters and alkylglycosides, and fatty acid alkanolamides.

The pH at 25 ° C. of the rinse agent composition of the present invention is preferably 2 or more, more preferably 2.5 or more, from the viewpoint of shortening the washing time, reducing the LPD, and improving the storage stability of the rinse agent composition. 3.0 or more is more preferable, and from the same viewpoint, 12 or less is preferable, 11.5 or less is more preferable, and 11.0 or less is more preferable. The pH can be adjusted by appropriately adding a pH adjusting agent as necessary. Here, the pH at 25 ° C. can be measured using a pH meter (Toa Denpa Kogyo Co., Ltd., HM-30G), and is a value one minute after the electrode is immersed in the rinse agent composition.

Although the content of each component described above is the content at the time of use, the rinse agent composition of the present invention may be stored and supplied in a concentrated state as long as its storage stability is not impaired. Good. In this case, it is preferable in that the manufacturing and transportation costs can be further reduced. The concentrate may be used after appropriately diluted with the above-mentioned aqueous medium as necessary. The concentration ratio is not particularly limited as long as the concentration at the time of polishing after dilution can be secured, but from the viewpoint of further reducing the production and transportation costs, it is preferably at least 2 times, more preferably at least 10 times, Preferably it is 20 times or more, and still more preferably 30 times or more.

When the rinse agent composition of the present invention is the above-described concentrated solution, the content of the water-soluble polymer A in the concentrated solution is preferably 0.02% by mass or more, more preferably from the viewpoint of reducing production and transportation costs. 0.1% by mass or more, more preferably 0.5% by mass or more, further preferably 1.0% by mass or more, still more preferably 1.5% by mass or more, and from the viewpoint of improving storage stability. Preferably, it is 20 mass% or less, More preferably, it is 15 mass% or less, More preferably, it is 10 mass% or less, More preferably, it is 7.0 mass% or less.

When the rinse agent composition of the present invention is the concentrated liquid, the pH of the concentrated liquid at 25 ° C. is preferably 1.5 or higher, more preferably 1.7 or higher, still more preferably 2.0 or higher, And preferably it is 12.5 or less, More preferably, it is 12.0 or less, More preferably, it is 11.5 or less.

[Production method of rinse agent composition]
The rinse agent composition of this invention can be manufactured by the manufacturing method including the process of mix | blending water-soluble polymer A, an aqueous medium, and an arbitrary component as needed by a well-known method, for example. In the present application, “mixing” includes mixing the water-soluble polymer A and optional components as necessary with an aqueous medium simultaneously or sequentially. There is no restriction | limiting in the mixing order of each component.

The blending can be performed, for example, using a mixer such as a homomixer, a homogenizer, an ultrasonic disperser, and a wet ball mill. The compounding quantity of each component in the manufacturing method of the rinse agent composition of this embodiment can be made the same as content of each component of the rinse agent composition mentioned above.

[Method for Manufacturing Semiconductor Substrate]
The rinse agent composition of this invention is used in order to remove the residue which remained on the surface of the silicon wafer after grind | polishing using the polishing liquid composition containing an abrasive grain and the water-soluble polymer B. FIG. An example of the method for producing a semiconductor substrate of the present invention includes a polishing step of polishing a silicon wafer to be polished (also referred to as “substrate to be polished”) using a polishing composition containing abrasive grains, and a silicon wafer after polishing. A rinsing process for rinsing with the rinsing agent composition of the present invention, and a cleaning process for cleaning the silicon wafer rinsed in the rinsing process (also referred to as “post-rinsing silicon wafer”). An example of the semiconductor substrate is, for example, a silicon wafer, and an example of the semiconductor substrate manufacturing method of the present invention is a silicon wafer manufacturing method. Another example of the method for producing a semiconductor substrate of the present invention is a method for producing a semiconductor substrate including a step of producing a silicon wafer by the method for producing a silicon wafer of the present invention, and the step uses a polishing liquid composition. A polishing process for polishing the silicon wafer to be polished, a rinsing process for rinsing the polished silicon wafer with the rinse agent composition of the present invention, and a cleaning process for cleaning the rinsed silicon wafer.

In the polishing step, a lapping (rough polishing) step of planarizing a silicon wafer obtained by slicing a silicon single crystal ingot into a thin disk shape, and etching the lapped silicon wafer, the silicon wafer surface There is a final polishing process that mirrors the surface.

In the polishing step, for example, a polishing liquid composition is supplied between the silicon wafer to be polished and the pad, and the pad is moved relative to the silicon wafer to be polished while the silicon wafer to be polished and the pad are in contact with each other. . Polishing conditions such as the number of revolutions of the pad, the number of revolutions of the substrate to be polished, the polishing load set in the polishing apparatus equipped with the pad, the supply speed of the polishing composition, and the polishing time are the same as conventionally known polishing conditions. Good.

The abrasive composition used in the polishing step preferably contains silica particles as abrasive grains and water-soluble polymer B from the viewpoint of improving the polishing rate and reducing the haze of the silicon wafer.

In the rinsing step, for example, a rinse agent composition is supplied between the polished silicon wafer and the pad, and the pad is moved relative to the polished silicon wafer in a state where the polished silicon wafer and the pad are in contact with each other. . The rinsing process in the rinsing process can be performed using a polishing apparatus used in the polishing process. The number of rotations of the pad, the number of rotations of the silicon wafer after polishing, the load set in the polishing apparatus equipped with the pad, the supply speed of the rinse agent composition, etc. may be the same as or different from the corresponding conditions in the polishing process. Good. The rinse time is preferably 1 second or more, more preferably 3 seconds or more from the viewpoint of suppressing the adhesion of abrasive grains, and preferably 60 seconds or less, more preferably 30 seconds or less from the viewpoint of improving productivity. . Here, the rinse time means the time during which the rinse agent composition is supplied.

The rinsing step may include a water rinsing treatment using water as a rinsing liquid before the rinsing treatment performed using the rinsing agent composition of the present invention. The water rinse treatment time is preferably 2 seconds or more and 30 seconds or less.

The pad used in the rinsing process may be the same as the pad used in the polishing process, and may be any kind such as a nonwoven fabric type or a suede type. Further, the pad used in the polishing step may be used as it is in the rinsing step without being exchanged. In this case, the pad may contain some abrasive grains of the polishing composition. The rinsing step may be performed on the silicon wafer that is still attached to the polishing apparatus immediately after the polishing step.

The temperature of the rinsing agent composition used in the rinsing step is preferably 5 to 60 ° C.

The rinsing step is preferably performed at least after the finish polishing step, but may be performed after each step of the rough polishing step and the finish polishing step.

In the cleaning step, for example, the rinsed silicon wafer is immersed in a cleaning agent, or the cleaning agent is injected onto the surface to be cleaned of the rinsed silicon wafer. A conventionally known cleaning agent may be used as the cleaning agent, and examples thereof include an aqueous solution containing ozone and an aqueous solution containing ammonium hydrogen fluoride. The cleaning time may be set according to the cleaning method.

The polishing composition used in the polishing step includes, for example, silica particles, a water-soluble polymer B, a nitrogen-containing basic compound, and an aqueous medium. The abrasive composition preferably contains a water-soluble polymer B from the viewpoint of achieving both improvement in polishing rate and reduction in LPD.

[Water-soluble polymer B]
(1) Water-soluble polymer B
The water-soluble polymer B is a water-soluble polymer in which the difference (z−z ₀ ) between the zeta potential z of the aqueous dispersion s and the zeta potential z ₀ of the aqueous dispersion s ₀ is 15 mV or more. Here, the aqueous dispersion s is composed of a water-soluble polymer B, silica particles, water, and hydrochloric acid or ammonia as necessary. The concentration of the water-soluble polymer B is 0.01% by mass, and the concentration of silica particles is A water-soluble polymer-containing silica water dispersion having a pH of 10.0% by mass and 10.0 at 25 ° C. The aqueous dispersion s ₀ is a silica aqueous dispersion comprising silica particles, water, and optionally hydrochloric acid or ammonia, and having a concentration of the silica particles of 0.1% by mass and a pH at 25 ° C. of 10.0. . The zeta potentials z and z ₀ can be measured by the method described in the examples. When the water-soluble polymer B is composed of two or more types of water-soluble polymers, a mixture of the two or more types of water-soluble polymers B has a property that the zeta potential difference (z−z ₀ ) is 15 mV or more.

The zeta potential difference (z−z ₀ ) is 15 mV or more, preferably 25 mV or more, more preferably 30 mV or more from the viewpoint of improving the polishing rate, and preferably 50 mV or less, more preferably 46 mV or less from the viewpoint of LPD reduction. It is.

The zeta potential z ₀ of the aqueous dispersion s ₀ is, for example, a predetermined value within a range of −50 mV to −70 mV, and is adjusted using, for example, a silica stock solution (“PL-3” manufactured by Fuso Chemical Co., Ltd.). The zeta potential (for example, −61 mV) of the prepared aqueous dispersion z ₀ .

The ratio (D / D ₀ ) between the secondary particle diameter D of the silica particles in the aqueous dispersion s and the secondary particle diameter D ₀ of the silica particles in the aqueous dispersion s ₀ is a viewpoint of improving the polishing rate. Therefore, it is preferably 1.10 or more, more preferably 1.15 or more, still more preferably 1.30 or more, and preferably 1.60 or less from the viewpoint of LPD reduction.

The secondary particle diameter D ₀ of the silica particles in the aqueous dispersion s ₀ is, for example, a predetermined value within the range of 64 to 73 nm, preferably a predetermined value within the range of 66 to 69 nm. This is the secondary particle size (for example, 67.7 nm) of silica particles in an aqueous dispersion s ₀ containing a silica stock solution (“PL-3” manufactured by Fuso Chemical Co., Ltd.) as a silica particle supply source.

The water-soluble polymer B is preferably at least one selected from the group consisting of polysaccharides, alkylacrylamide polymers, polyvinyl alcohol (PVA), and polyvinyl alcohol derivatives (excluding anion-modified polyvinyl alcohol). . As the polysaccharide, hydroxyethyl cellulose (HEC) is preferable. As the alkyl acrylamide polymer, poly (hydroxy) alkyl acrylamide and polyalkyl acrylamide are preferable, and polyhydroxyethyl acrylamide (pHEAA) is more preferable. The polyvinyl alcohol derivative is preferably polyvinyl alcohol / polyethylene glycol / graft copolymer (PEG-g-PVA) or polyethylene oxide-modified polyvinyl alcohol. Among these, the water-soluble polymer B is preferably HEC, poly (hydroxy) alkylacrylamide, PVA, PEG-g-PVA, and polyethylene oxide-modified polyvinyl alcohol from the viewpoint of achieving both improvement in polishing rate and reduction in LPD. At least one selected from the group consisting of, more preferably at least one selected from the group consisting of HEC, pHEAA, and PVA, more preferably at least one selected from HEC, and pHEAA. Even more preferred is HEC.

The weight average molecular weight of the water-soluble polymer B is preferably 10,000 or more, more preferably 50,000 or more, still more preferably 100,000 or more, from the viewpoint of achieving both improvement of the polishing rate and LPD reduction. From the viewpoint, it is preferably 5 million or less, more preferably 3 million or less, and still more preferably 1 million or less. The weight average molecular weight of the water-soluble polymer B can be measured by the method described in the examples.

The content of the water-soluble polymer B in the polishing composition is preferably 0.001% by mass or more, more preferably 0.003% by mass or more, and still more preferably 0.005% by mass from the viewpoint of improving the polishing rate. From the same viewpoint, it is preferably 1.0% by mass or less, more preferably 0.5% by mass or less, and still more preferably 0.1% by mass or less.

When the water-soluble polymer A contained in the rinse agent composition used in the rinsing step is at least one selected from polyglycerin and polyglycerin derivatives, the water-soluble polymer contained in the polishing liquid composition used in the polishing step The high molecular weight polymer B is preferably HEC and poly (hydroxy) alkylacrylamide from the viewpoint of achieving both improvement in polishing rate and reduction in LPD. When the water-soluble polymer A contained in the rinse agent composition used in the rinsing step is a polyglycerin derivative, the water-soluble polymer B contained in the polishing composition used in the polishing step is HEC. preferable. In this case, the polyglycerol derivative preferably contains a polyglycerol alkyl ether, and more preferably a polyglycerol alkyl ether.

[Silica particles]
From the viewpoint of improving the surface smoothness of the silicon wafer, the silica particles contained in the polishing composition are more preferably colloidal silica, and from the viewpoint of preventing contamination of the silicon wafer with alkali metal, alkaline earth metal, etc. It is preferable that it is obtained from the hydrolyzate. The average primary particle diameter of the silica particles contained in the polishing composition is preferably 5 nm or more, more preferably 10 nm or more from the viewpoint of securing a high polishing rate, and preferably 50 nm or less from the viewpoint of reducing the LPD. More preferably, it is 45 nm or less. The average primary particle diameter of the silica particles can be calculated using the specific surface area S (m ² / g) calculated by the BET (nitrogen adsorption) method.

The degree of association of the silica particles is preferably 1.1 or more and 3.0 or less, more preferably 1.8 or more and 2.5 or less, from the viewpoint of securing a high polishing rate and reducing LPD. The association degree of silica particles is a coefficient representing the shape of silica particles, and is calculated by the following formula. The average secondary particle diameter is a value measured by a dynamic light scattering method, and can be measured using, for example, the apparatus described in the examples.
Degree of association = average secondary particle size / average primary particle size

The content of silica particles contained in the polishing liquid composition is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, from the viewpoint of ensuring a high polishing rate, and economic efficiency, and From the viewpoint of suppressing aggregation of silica particles and improving dispersion stability in the polishing composition, it is preferably 10% by mass or less, more preferably 7.5% by mass or less.

[Nitrogen-containing basic compound]
The nitrogen-containing basic compound contained in the polishing composition is at least one selected from an amine compound and an ammonium compound from the viewpoints of ensuring a high polishing rate and reducing surface roughness (haze) and surface defects (LPD). These nitrogen-containing basic compounds are, for example, ammonia, ammonium hydroxide, ammonium carbonate, ammonium hydrogen carbonate, dimethylamine, trimethylamine, diethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-methyl-N, N-diethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dibutylethanolamine, N- (β-aminoethyl) ethanolamine, monoisopropanol Ami , Diisopropanolamine, triisopropanolamine, ethylenediamine, hexamethylenediamine, piperazine hexahydrate, anhydrous piperazine, 1- (2-aminoethyl) piperazine, N-methylpiperazine, diethylenetriamine, tetramethylammonium hydroxide, and hydroxy An amine etc. are mentioned. Among these, ammonia, a mixture of ammonia and hydroxyamine is preferable, and ammonia is more preferable.

The content of the nitrogen-containing basic compound contained in the polishing composition is preferably 0.001 from the viewpoint of reducing the surface roughness (haze) and surface defects (LPD) of the silicon wafer and ensuring a high polishing rate. From the viewpoint of reducing the surface roughness (haze) and surface defects (LPD) of the silicon wafer, it is preferably 1% by mass or less, more preferably 0% by mass or more, more preferably 0.005% by mass or more. .5% by mass or less.

[Aqueous medium]
The aqueous medium contained in the polishing liquid composition may be the same as the aqueous medium contained in the rinse agent composition of the present invention. The content of the aqueous medium in the polishing liquid composition may be, for example, the residue excluding silica particles, water-soluble polymer B, nitrogen-containing basic compound, and optional components described below.

The pH of the polishing composition at 25 ° C. is preferably 8 or more, more preferably 9 or more, still more preferably 10 or more from the viewpoint of ensuring a high polishing rate, and preferably 12 or less from the viewpoint of safety. More preferably, it is 11 or less. The pH can be adjusted by appropriately adding a nitrogen-containing basic compound and / or a pH adjuster. Here, the pH at 25 ° C. can be measured using a pH meter (Toa Denpa Kogyo Co., Ltd., HM-30G), and is a value one minute after the electrode is immersed in the polishing composition.

The polishing composition can be produced, for example, by a production method including a step of blending silica particles, a water-soluble polymer B, an aqueous medium, a nitrogen-containing basic compound, and optional components as necessary, by a known method. Examples of the optional component include at least one optional component selected from water-soluble polymers other than the water-soluble polymer B, pH adjusters, preservatives, alcohols, chelating agents, and nonionic surfactants.

The semiconductor substrate manufacturing method of the present invention may further include an element isolation film forming process, an interlayer insulating film flattening process, a metal wiring forming process and the like in addition to the silicon wafer manufacturing process.

[Rinse method]
The method for rinsing a silicon wafer of the present invention (hereinafter also referred to as “the rinsing method of the present invention”) includes a rinsing step of rinsing the silicon wafer after polishing using the rinse agent composition of the present invention. The rinsing step in the rinsing method of the present invention can be performed in the same manner as the rinsing step in the above-described method for manufacturing a silicon wafer of the present invention and the method for manufacturing a semiconductor substrate of the present invention. In the rinsing method of the present invention, since the rinse agent composition of the present invention is used in the rinsing step, the residual amount of abrasive grains on the silicon wafer after polishing can be remarkably reduced. Since it can be suppressed, the cleaning time of the silicon wafer performed after rinsing can be shortened and LPD can be reduced.

The present invention further relates to the following composition, production method and the like.

[1] A rinse agent composition for silicon wafers comprising a water-soluble polymer and an aqueous medium,
The water-soluble polymer is
It consists of the water-soluble polymer, silica particles, water, and hydrochloric acid or ammonia as necessary. The concentration of the water-soluble polymer is 0.1% by mass, the concentration of the silica particles is 0.1% by mass, 25 A zeta potential Z of a water-soluble polymer-containing silica aqueous dispersion (aqueous dispersion S) having a pH of 7.0 at 0 ° C., silica particles, water, and optionally hydrochloric acid or ammonia. Water solubility in which the difference (Z−Z ₀ ) from the zeta potential Z ₀ of the silica aqueous dispersion (aqueous dispersion S ₀ ) having a concentration of 0.1% by mass and a pH of 7.0 at 25 ° C. is 25 mV or less A rinse composition for silicon wafers, which is a polymer.
[2] A rinsing agent composition for a silicon wafer comprising a water-soluble polymer and an aqueous medium,
A rinsing agent composition for silicon wafers, wherein the water-soluble polymer contains at least one selected from the group consisting of polyglycerin, polyglycerin derivatives, polyglycidol, polyglycidol derivatives, polyvinyl alcohol derivatives, and polyacrylamide.
[3] The rinse agent composition for silicon wafers according to [1], wherein the difference (Z−Z ₀ ) is preferably 15 mV or less, more preferably 9 mV or less, and even more preferably 7 mV or less.
[4] The water-soluble polymer is
The ratio (d / d ₀ ) between the secondary particle diameter d of the silica particles in the aqueous dispersion S and the secondary particle diameter d ₀ of the silica particles in the aqueous dispersion S ₀ is preferably 1.35. Or less, more preferably 1.17 or less, still more preferably 1.10 or less, even more preferably 1.08 or less, and preferably 1.00 or more, more preferably 1.02 or more, and still more preferably 1. The rinse composition for a silicon wafer according to the above [1] or [3], which is a water-soluble polymer of 0.04 or more, and even more preferably 1.05 or more.
[5] The water-soluble polymer is preferably at least one selected from the group consisting of polyglycerin, polyglycerin derivatives, polyglycidol, polyglycidol derivatives, polyvinyl alcohol derivatives, and polyacrylamide. The rinse agent composition for silicon wafers in any one of [3] and [4].
[6] The polyglycerin derivative is preferably a polyglycerin obtained by adding a functional group to an ether bond or an ester bond, and more preferably a polyglycerin obtained by adding a functional group to an ether bond. The rinse agent composition for silicon wafers according to [5].
[7] The rinse composition for silicon wafers according to [5], wherein the polyglycerol derivative is preferably an alkyl ether of polyglycerol.
[8] The water-soluble polymer is preferably selected from the group consisting of polyglycerol, polyglycerol alkyl ether, polyglycerol dialkyl ether, polyglycerol fatty acid ester, polyethylene oxide modified polyvinyl alcohol, sulfonic acid modified polyvinyl alcohol, and polyacrylamide. The rinse agent composition for silicon wafers according to any one of [1] to [4], which is at least one selected, and more preferably polyglycerin alkyl ether.
[9] The rinse composition for a silicon wafer according to any one of [1] to [4], wherein the water-soluble polymer preferably contains both polyglycerin and polyglycerin alkyl ether.
[10] The number of carbon atoms of the hydrophobic group of the polyglycerol derivative is preferably 6 or more, more preferably 8 or more, and preferably 22 or less, more preferably 18 or less, [2], [5] To [7]. A rinsing agent composition for silicon wafers.
[11] The mass ratio (polyglycerin / polyglycerin alkyl ether) is preferably 0.5 or more, more preferably 1.0 or more, still more preferably 2.0 or more, and preferably 10 or less, more preferably Is 6.0 or less, more preferably 5.0 or less, the rinse agent composition for silicon wafers according to the above [9].
[12] The weight average molecular weight of the water-soluble polymer is preferably 500 or more, more preferably 700 or more, still more preferably 900 or more, and preferably 1,500,000 or less, more preferably 500,000. The silicon wafer according to any one of [2], [5] to [11], which is more preferably 100,000 or less, still more preferably 25,000 or less, and still more preferably 10,000 or less. Rinsing agent composition.
[13] The water-soluble polymer is preferably a pentamer or more, more preferably a 10-mer or more, still more preferably a 15-mer or more, and preferably a 5,000-mer or less, more preferably 500. The above-mentioned [2], [5] to [12], which is a monomer or less, more preferably a 200-mer or less, still more preferably a 150-mer or less, and still more preferably a 100-mer or less. Rinsing agent composition for silicon wafers.
[14] The content of the water-soluble polymer in the rinse agent composition is preferably 0.001% by mass or more, more preferably 0.015% by mass or more, still more preferably 0.020% by mass or more, and still more preferably. Is 0.025% by mass or more, more preferably 0.03% by mass or more, and preferably 1.0% by mass or less, more preferably 0.7% by mass or less, and further preferably 0.4% by mass. Hereinafter, the rinse agent composition for silicon wafers according to any one of [1] to [13], which is still more preferably 0.1% by mass or less, and still more preferably 0.08% by mass or less.
[15] The water-soluble polymer is at least one water-soluble polymer a1 selected from the group consisting of polyglycerin, polyglycerin derivatives, polyglycidol, polyglycidol derivatives, polyvinyl alcohol derivatives, and polyacrylamide, and a betaine structure. The rinse agent composition for silicon wafers according to [1] above, which is a mixture with a water-soluble polymer a2 containing
[16] The rinse composition for silicon wafers according to [15], wherein the water-soluble polymer is a mixture of polyglycerin alkyl ether and a water-soluble polymer a2 containing a betaine structure.
[17] The silicon wafer rinse according to any one of [15] and [16], wherein the difference (Z−Z ₀ ) is preferably 15 mV or less, more preferably 12 mV or less, and further preferably 9 mV or less. Agent composition.
[18] The water-soluble polymer is
The ratio (d / d ₀ ) between the secondary particle diameter d of the silica particles in the aqueous dispersion S and the secondary particle diameter d ₀ of the silica particles in the aqueous dispersion S ₀ is preferably 1.35. Or less, more preferably 1.34 or less, still more preferably 1.33 or less, still more preferably 1.32 or less, and preferably 1.00 or more, more preferably 1.25 or more, still more preferably 1. The rinsing composition for silicon wafers according to any one of [15] to [17], which is a water-soluble polymer that is 30 or more, and even more preferably 1.31 or more.
[19] The content of the water-soluble polymer a2 in the rinse agent composition is preferably 0.00001% by mass or more, more preferably 0.00005% by mass or more, and further preferably 0.0001% by mass or more. And the rinse agent composition for silicon wafers according to any one of [15] to [18], which is preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably 1% by mass or less.
[20] The mass ratio of the water-soluble polymer a1 and the water-soluble polymer a2 (water-soluble polymer a1 / water-soluble polymer a2) is preferably 0.5 or more, more preferably 1 or more, and still more preferably. The rinse composition for silicon wafers according to any one of [15] to [19], which is 2 or more, and preferably 500 or less, more preferably 200 or less, and still more preferably 100 or less.
[21] The rinse agent composition for silicon wafers according to any one of [15] to [20], wherein the water-soluble polymer a2 includes a structural unit A represented by the following formula (1).

However, in the formula (1),
R ¹ to R ³ : the same or different, a hydrogen atom, a methyl group, or an ethyl group R ⁴ : an alkylene group having 1 to 4 carbon atoms, or —Y ¹ —OPO ₃ ^— —Y ² —
Y ¹ , Y ² : the same or different, an alkylene group having 1 to 4 carbon atoms R ⁵ , R ⁶ : the same or different, a hydrocarbon group having 1 to 4 carbon atoms X ¹ : O or NR ⁷
R ⁷ : a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms X ² : a hydrocarbon group having 1 to 4 carbon atoms, —R ¹⁷ SO ₃ ⁻ , or —R ¹⁸ COO ⁻
R ¹⁷ and R ^{18 are the} same or different and each represents an alkylene group having 1 to 4 carbon atoms.
X ² is —R ¹⁷ SO ₃ ⁻ or —R ¹⁸ COO ^— when R ⁴ is an alkylene group having 1 to ⁴ carbon atoms, and R ⁴ is —Y ¹ —OPO ₃ ^— —Y ^2. In the case of-, it is a hydrocarbon group having 1 to 4 carbon atoms.
[22] The rinse agent composition for silicon wafers according to [21], wherein the water-soluble polymer a2 includes a structural unit B represented by the following formula (2).

However, in Formula (2),
R ⁸ to R ¹⁰ : the same or different, hydrogen atom, methyl group or ethyl group X ³ : O or NR ¹⁹
R ¹⁹ : a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms R ¹¹ : an alkylene group having 1 to 22 carbon atoms (however, the hydrogen atom of the alkylene group may be substituted with a hydroxyl group) or — (AO) _m — (Where AO is an alkyleneoxy group having 2 to 4 carbon atoms, and m is 1 to 150 in terms of the average number of moles added.)
X ⁴ : hydrogen atom, hydrocarbon group having 1 to 4 carbon atoms (however, the hydrogen atom of the hydrocarbon group may be substituted with a hydroxyl group), hydroxyl group, N ⁺ R ¹² R ¹³ R ¹⁴ or NR ¹⁵ R ¹⁶
R ¹² to R ^{16 are the} same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms.
[23] The molar ratio of the structural unit A to the structural unit B (structural unit A / structural unit B) in the water-soluble polymer a2 is preferably 10/90 or more, more preferably 20/80 or more, and still more preferably. Is 30/70 or more, and preferably 98/2 or less, more preferably 95/5 or less, the rinse agent composition for silicon wafers according to the above [22].
[twenty four]
The rinse agent composition for silicon wafers according to any one of [1] to [23], further including a basic compound.
[25] The pH of the rinse agent composition at 25 ° C. is preferably 2 or more, more preferably 2.5 or more, more preferably 3.0 or more, and preferably 12 or less, more preferably 11. The rinse agent composition for silicon wafers according to any one of [1] to [24], which is 5 or less, more preferably 11.0 or less.
[26] The rinse composition for a silicon wafer is a rinse composition for a silicon wafer used for a silicon wafer polished with a polishing liquid composition containing silica particles and a water-soluble polymer. ,
[1], [3] to [25], wherein the silica particles used for the preparation of the aqueous dispersion S and the aqueous dispersion S ₀ are the same as the silica particles contained in the polishing liquid composition. The rinse agent composition for silicon wafers in any one of.
[27] A method for rinsing a silicon wafer, including a step of rinsing a polished silicon wafer using the rinse agent composition according to any one of [1] to [26].
[28] A method for producing a semiconductor substrate, comprising a step of rinsing a polished silicon wafer using the rinse agent composition according to any one of [1] to [26].
[29] A polishing step of polishing a silicon wafer to be polished using a polishing liquid composition containing silica particles and a water-soluble polymer;
A rinsing step of rinsing the polished silicon wafer using the rinse agent composition according to any one of [1] to [26];
Cleaning the rinsed silicon wafer, and
A method for producing a semiconductor substrate, wherein the silica particles used in the preparation of the aqueous dispersion S and the aqueous dispersion S ₀ are the same as the silica particles contained in the polishing liquid composition.
[30] The polishing step is preferably a rough polishing step for planarizing a silicon wafer obtained by slicing a silicon single crystal ingot into a thin disk shape, or after etching a lapped silicon wafer, The method for manufacturing a semiconductor substrate according to [29], wherein the polishing is a mirror polishing, more preferably the final polishing step.
[31] When the water-soluble polymer contained in the rinse agent composition according to any one of [1] to [26] is referred to as a water-soluble polymer A,
A polishing step of polishing a silicon wafer to be polished using a polishing liquid composition containing silica particles, a water-soluble polymer B, a nitrogen-containing basic compound, and an aqueous medium;
A rinsing step of rinsing the polished silicon wafer using the rinsing agent composition according to any one of [1] to [26];
And a cleaning process for cleaning the rinsed silicon wafer.
[32] The water-soluble polymer B is
It consists of the water-soluble polymer, silica particles, water, and hydrochloric acid or ammonia as necessary. The concentration of the water-soluble polymer is 0.01% by mass, the concentration of the silica particles is 0.1% by mass, 25 A zeta potential z of a water-soluble polymer-containing silica aqueous dispersion (aqueous dispersion s) having a pH of 10.0 at 0 ° C., silica particles, water, and optionally hydrochloric acid or ammonia, Water solubility in which the difference (z−z ₀ ) from the zeta potential z ₀ of a silica aqueous dispersion (aqueous dispersion s ₀ ) having a concentration of 0.1% by mass and a pH of 10.0 at 25 ° C. is 15 mV or more The method for producing a silicon wafer according to [31], which is the polymer B.
[33] The water-soluble polymer B is
The ratio (D / D ₀ ) between the secondary particle diameter D of the silica particles in the aqueous dispersion s and the secondary particle diameter D ₀ of the silica particles in the aqueous dispersion s ₀ is 1.10 or more. The method for producing a silicon wafer according to [32], which is a water-soluble polymer.
[34] The water-soluble polymer B is at least one selected from the group consisting of polysaccharides, alkylacrylamide polymers, polyvinyl alcohol, and polyvinyl alcohol derivatives (excluding anion-modified polyvinyl alcohol). [31] The method for producing a silicon wafer according to any one of [33].
[35] The water-soluble polymer B is hydroxyethyl cellulose,
The method for producing a silicon wafer according to any one of [31] to [34], wherein the water-soluble polymer A is a polyglycerin derivative.
[36] The method for producing a silicon wafer according to any one of [31] to [35], wherein in the rinsing step, a water rinsing process using water as a rinsing liquid is performed before the rinsing process.
[37] The method for manufacturing a silicon wafer according to any one of [31] to [36], wherein the rinsing process in the rinsing process is performed using a polishing apparatus used in the polishing process.
[38] A method for manufacturing a semiconductor substrate, comprising a step of manufacturing a silicon wafer by the method for manufacturing a silicon wafer according to any one of [31] to [37].

1. Measuring method of various parameters (1) Measuring method of zeta potential of aqueous dispersion S ₀ , S, s ₀ , s The aqueous dispersion was put into capillary cell DTS1070, and “Zeta Sizer Nano ZS” manufactured by Malvern was used. The zeta potential was measured under the following conditions.
Sample: Refractive index: 1.450 Absorption rate: 0.010
Dispersion medium: viscosity: 0.8872 cP, refractive index: 1.330, dielectric constant: 78.5
Temperature: 25 ° C

(1-1) Preparation of Silica Aqueous Dispersion (Aqueous Dispersion S ₀ ) Ion exchange water was added to a silica particle stock solution (“PL-3” manufactured by Fuso Chemical Co., Ltd.). An aqueous hydrochloric acid solution or an aqueous ammonia solution was added so as to be 7.0, and thus an aqueous dispersion S ₀ having a silica particle concentration of 0.1% by mass was obtained.

(1-2) Preparation of Water-Soluble Polymer-Containing Silica Water Dispersion (Water Dispersion S) In ion-exchanged water, each water-soluble polymer A and then a silica particle stock solution (“PL-3” manufactured by Fuso Chemical Co., Ltd.) Added. Thereafter, an aqueous hydrochloric acid solution or an aqueous ammonia solution is added thereto so that the pH at 25 ° C. is 7.0, the concentration of the water-soluble polymer is 0.1% by mass, and the concentration of the silica particles is 0.1% by mass. % Aqueous dispersion S was obtained.

(2-1) Preparation of Silica Water Dispersion (Water Dispersion s ₀ ) Ion exchange water was added to the silica particle stock solution (“PL-3” manufactured by Fuso Chemical Co., Ltd.), and then the pH at 25 ° C. was increased. An aqueous hydrochloric acid solution or an aqueous ammonia solution was added so that the concentration was 10.0 to obtain an aqueous dispersion s ₀ having a silica particle concentration of 0.1% by mass.

(2-2) Preparation of Water-Soluble Polymer-Containing Silica Water Dispersion (Water Dispersion s) In ion-exchanged water, each water-soluble polymer B and then a silica particle stock solution (“PL-3” manufactured by Fuso Chemical Co., Ltd.) Added. Thereafter, an aqueous hydrochloric acid solution or an aqueous ammonia solution is added thereto so that the pH at 25 ° C. is 10.0, the concentration of the water-soluble polymer is 0.01% by mass, and the concentration of the silica particles is 0.1% by mass. % Aqueous dispersion S was obtained.

(2) Method for Measuring Secondary Particle Size of Silica Particles Silica aqueous dispersions S ₀ , S, s ₀ , and s are placed in Disposable Sizing Cuvette (polystyrene 10 mm cell) to a height of 10 mm from the bottom and made by Malvern. Measured by a dynamic light scattering method using “Zetasizer Nano ZS”, and the value of the Z average particle size is determined as the secondary particle size d ₀ , d, D of the silica water dispersion S ₀ , S, s ₀ , s ₀ and D. The measurement conditions are described below.
Sample: Refractive index: 1.450, Absorption rate: 0.010
Dispersion medium: Viscosity: 0.8872 cP, Refractive index: 1.330
Temperature: 25 ° C

(3) Measurement of weight average molecular weight of water-soluble polymer The weight average molecular weight of the water-soluble polymer A used for the preparation of the rinse agent composition and the water-soluble polymer B used for the preparation of the polishing composition was determined by gel permeation. It calculated based on the peak in the chromatogram obtained by applying the anation chromatography (GPC) method on the following conditions.
Equipment: HLC-8320 GPC (Tosoh Corporation, detector integrated type)
Column: GMPWXL + GMPWXL (anion)
Eluent: 0.2M phosphate buffer / CH ₃ CN = 9/1
Flow rate: 0.5mL / min
Column temperature: 40 ° C
Detector: RI Detector Standard: Monodispersed polyethylene glycol with known weight average molecular weight

2. Preparation of rinse agent composition Water-soluble polymer A listed in Tables 1 and 2 and ion-exchanged water are mixed with stirring, and if necessary, aqueous hydrochloric acid or 28% by mass ammonia water (Kishida Chemical Co., Ltd. reagent special grade) Was used to adjust the pH at 25 ° C. to 7.0, and the rinse agent compositions of Examples 1 to 17 and Comparative Examples 1 to 5 (both concentrated solutions) were obtained. However, Example 9 was adjusted such that the pH was 4.0, Example 10 was adjusted so that the pH was 10.0, and Comparative Example 5 was prepared so that the ammonia concentration was 5 ppm. The remainder excluding the water-soluble polymer, hydrochloric acid or ammonia is ion-exchanged water. In addition, content of each component in Table 1 is a value about the rinse agent composition obtained by diluting the concentrate 20 times. The rinse agent compositions of Examples 18 to 27 and Comparative Example 6 (both concentrated solutions) each had a pH of 7.0 at 25 ° C., and when diluted 20-fold, contained the water-soluble polymer A The amount was adjusted to be 0.05% by mass. However, Examples 25 to 27 were prepared so that the polyglycerin alkyl ether was 0.049% by mass and the water-soluble polymer having a betaine structure was 0.001% by mass.

Details of the water-soluble polymers used in the preparation of the rinse agent compositions of Examples 1-27 and Comparative Examples 1-6 and the abrasive compositions of Examples 18-27 and Comparative Example 6 below are as follows. It is.
A1: PGL 20PW (polyglycerin 20-mer): Daicel A2: PGL XPW (polyglycerin 40-mer): Daicel A3: PGL 100PW (polyglycerin 100-mer): Daicel A4: Cell Morris B044 ( Polyglycerin 20-mer lauryl ether): Daicel A5: Polyacrylamide (Mw 10,000): Polysciences A6: Polyacrylamide (Mw 600,000 to 1,000,000): Polysciences A7: Goceran L-3266 (Mw 23,000): Nippon Synthetic Chemical Industry A8: Kollicoat IR (Mw 26,500): BASF A9: Lipidure-HM (Mw100,000): NOF A10: Lipidure-PMB (Mw600, 00, the molar ratio (MPC / BMA) =
80:20): NOF Corporation A11: MPC / LMA (Mw 100,000): Kao A51: Poly (N-isopropylamide) (Mn 20,000 to 40,000): ALDRICH A52: SE400 (Mw 250,000) ): Daicel A53: PVA-117 (Mw 75000): Kuraray A54: Poly (ethylene oxide) (Mw 200000): Polysciences A55: n-Decypentoxyethylene: Bachem AG, Aacrylamide: Polyacrylamide Mw 700000)

Details of each structural unit of the water-soluble polymers A9 to A11 are as shown in Table 3 below, and a method for synthesizing the water-soluble polymer A11 is as follows.

[Water-soluble polymer A11]
10.0 g of ethanol was put into a four-necked flask having an internal volume of 300 mL, and the temperature was raised to 70 ° C. A solution obtained by mixing 5.0 g of MPC (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.1 g of LMA (manufactured by Wako Pure Chemical Industries, Ltd.) and 10.0 g of ethanol, and 2,2′-azobis A solution obtained by mixing 0.021 g of (isobutyronitrile) (manufactured by Wako Pure Chemical Industries, Ltd.) and 4.4 g of ethanol was separately dropped over 2 hours for polymerization. After aging for 6 hours, the solvent was distilled off under reduced pressure and replaced with water to obtain an aqueous polymer solution containing a water-soluble polymer A11 (a copolymer of MPC and LMA). The molar ratio (MPC / LMA) of the structural units in the water-soluble polymer A11 was 80/20, and the weight average molecular weight of the water-soluble polymer A11 was 100,000.

3. Rinsing Method A rinse agent composition obtained by diluting a rinse agent composition (concentrated solution) 20 times with ion-exchanged water was filtered with a filter (advancetech's compact cartridge filter “MCP-LX-C10S” immediately before the start of the rinse treatment). )), And the following silicon wafer (silicon single-sided mirror wafer with a diameter of 200 mm (conductivity type: P, crystal orientation: 100, resistivity 0.1 Ω · cm or more and less than 100 Ω · cm)) A rinsing treatment was performed. Prior to the rinse treatment, rough polishing was performed on the silicon wafer in advance using a commercially available abrasive composition. The haze of the silicon wafer subjected to the final polishing after finishing the rough polishing was 2.680 (ppm). Haze is a value in a dark field wide oblique incidence channel (DWO) measured using “Surfscan SP1-DLS” manufactured by KLA Tencor. Thereafter, finish polishing was performed under the following conditions, and immediately after that, rinse treatment was performed under the following conditions using each rinse agent composition.

[Abrasive composition used for finish polishing]
The abrasive composition used in the final polishing performed before the rinsing process using the rinse agent compositions of Examples 1 to 17 and Comparative Examples 1 to 5 was SE-400 (manufactured by Daicel Corporation, HEC, Molecular weight 250,000), PEG 6000 (Wako Pure Chemical Industries, Ltd., Wako First Grade), ammonia water (Kishida Chemical Co., Ltd., reagent special grade), PL-3 (manufactured by Fuso Chemical Industry Co., Ltd.), ion-exchanged water A concentrated solution was obtained by stirring and mixing, and then the concentrated solution was diluted 40 times with ion-exchanged water just before use. The composition of the abrasive composition used in the final polishing is as follows.
Silica particles (PL-3, average primary particle size 35 nm, average secondary particle size 69 nm, association degree 2.0): 0.17% by mass
HEC (SE-400): 0.01% by mass
Ammonia: 0.01% by mass
PEG (weight average molecular weight 6000); 0.0008% by mass

The compositions of the polishing liquid compositions of Examples 18 to 27 and Comparative Example 6 shown in Table 2 are as follows.
Silica particles (PL-3, average primary particle size 35 nm, average secondary particle size 69 nm, association degree 2.0): 0.17% by mass
Water-soluble polymer B: 0.01% by mass
Ammonia: 0.01% by mass
PEG (weight average molecular weight 6000); 0.0008% by mass

[Finishing polishing conditions]
Polishing machine: Single-sided 8-inch polishing machine "GRIND-X SPP600s" manufactured by Okamoto
Polishing pad: Suede pad manufactured by Toray Cortex Co., Ltd. (Asker hardness: 64, thickness: 1.37 mm, nap length: 450 μm, opening diameter: 60 μm)
Silicon wafer polishing pressure: 100 g / cm ²
Surface plate rotation speed: 60 rpm
Polishing time: 5 minutes Supply rate of the abrasive composition: 150 g / min Temperature of the abrasive composition: 23 ° C.
Carrier rotation speed: 60rpm

[Rinse condition]
Polishing machine: Single-sided 8-inch polishing machine "GRIND-X SPP600s" manufactured by Okamoto
Polishing pad: Suede pad manufactured by Toray Cortex Co., Ltd. (Asker hardness: 64, thickness: 1.37 mm, nap length: 450 um, opening diameter: 60 um)
Silicon wafer rinse pressure: 60 g / cm ²
Surface plate rotation speed: 30 rpm
Rinse time: 10 seconds Feed rate of rinse agent composition: 1000 mL / min Temperature of rinse agent composition: 23 ° C.
Carrier rotation speed: 30rpm

4). Cleaning method After rinsing, the silicon wafer was subjected to ozone cleaning and dilute hydrofluoric acid cleaning as follows. In ozone cleaning, an aqueous solution containing 20 ppm of ozone was sprayed from a nozzle toward the center of a silicon wafer rotating at 600 rpm at a flow rate of 1 L / min for 3 minutes. At this time, the temperature of the ozone water was normal temperature. Next, dilute hydrofluoric acid cleaning was performed. In dilute hydrofluoric acid cleaning, an aqueous solution containing 0.5% by mass of ammonium hydrogen fluoride (special grade: Nakarai Tex Co., Ltd.) is sprayed from a nozzle toward the center of a silicon wafer rotating at 600 rpm at a flow rate of 1 L / min for 5 seconds. did. The above ozone cleaning and dilute hydrofluoric acid cleaning were performed as a set, for a total of 2 sets, and finally spin drying was performed. In spin drying, the silicon wafer was rotated at 1500 rpm.

5). Evaluation of LPD on silicon wafer For evaluation of LPD on the surface of silicon wafer after cleaning, surface roughness measuring device “Surfscan SP1-DLS” (manufactured by KLA Tencor) is used. It was evaluated by measuring the number of particles. The LPD evaluation results indicate that the smaller the numerical value, the fewer surface defects. The LPD measurements were performed on two silicon wafers, and the average values are shown in Tables 1 and 2, respectively.

6). Evaluation of polishing rate The polishing rate was evaluated by the following method. The weight of each silicon wafer before and after polishing was measured using a precision balance (“BP-210S” manufactured by Sartorius), and the obtained weight difference was divided by the density, area and polishing time of the silicon wafer, and unit time The single-side polishing rate per hit was determined. The results are shown in Table 2 as relative values with the polishing rate of Comparative Example 6 set to 1.00.

As shown in Table 1, by using the rinse agent compositions of Examples 1 to 17, LPD was reduced more favorably than when the rinse agent compositions of Comparative Examples 1 to 5 were used. Therefore, when the rinse agent compositions of Examples 1 to 17 are used, the cleaning time can be shortened as compared with the case where the rinse agent compositions of Comparative Examples 1 to 5 are used.

As shown in Table 2, in Examples 18 to 27 using the water-soluble polymer A having a potential difference (Z−Z ₀ ) of 25 mV or less, the polishing rate was improved and LPD was compared with Comparative Example 6. It is possible to achieve both reductions.

The use of the rinse agent composition of the present invention can shorten the cleaning time of the silicon wafer, and thus contributes to improvement of productivity and cost reduction in the production of a semiconductor substrate.

Claims

A rinse composition for a silicon wafer, comprising a water-soluble polymer and an aqueous medium,
The water-soluble polymer is
It consists of the water-soluble polymer, silica particles, water, and hydrochloric acid or ammonia as necessary. The concentration of the water-soluble polymer is 0.1% by mass, the concentration of the silica particles is 0.1% by mass, 25 A zeta potential Z of a water-soluble polymer-containing silica aqueous dispersion (aqueous dispersion S) having a pH of 7.0 at 0 ° C., silica particles, water, and optionally hydrochloric acid or ammonia. Water solubility in which the difference (Z−Z 0 ) from the zeta potential Z 0 of the silica aqueous dispersion (aqueous dispersion S 0 ) having a concentration of 0.1% by mass and a pH of 7.0 at 25 ° C. is 25 mV or less A rinse composition for silicon wafers, which is a polymer.
A rinse composition for a silicon wafer, comprising a water-soluble polymer and an aqueous medium,
The rinse composition for silicon wafers, wherein the water-soluble polymer contains at least one selected from the group consisting of polyglycerin, polyglycerin derivatives, polyglycidol, polyglycidol derivatives, polyvinyl alcohol derivatives, and polyacrylamide.
The water-soluble polymer is
The ratio (d / d 0 ) between the secondary particle diameter d of the silica particles in the aqueous dispersion S and the secondary particle diameter d 0 of the silica particles in the aqueous dispersion S 0 is 1.35 or less. The rinse agent composition for silicon wafers according to claim 1, which is a water-soluble polymer.
The silicon wafer according to claim 1 or 3, wherein the water-soluble polymer is at least one selected from the group consisting of polyglycerin, polyglycerin derivatives, polyglycidol, polyglycidol derivatives, polyvinyl alcohol derivatives, and polyacrylamide. Rinsing agent composition.
The rinse composition for silicon wafers according to claim 4, wherein the polyglycerol derivative is an alkyl ether of polyglycerol.
The rinse agent composition for silicon wafers according to any one of claims 1 to 5, further comprising a basic compound.
A method for rinsing a silicon wafer, comprising a step of rinsing a polished silicon wafer using the rinse agent composition according to any one of claims 1 to 6.
A method for producing a semiconductor substrate, comprising a step of rinsing a polished silicon wafer using the rinse agent composition according to any one of claims 1 to 6.
When the water-soluble polymer contained in the rinse agent composition according to any one of claims 1 to 6 is referred to as a water-soluble polymer A,
A polishing step of polishing a silicon wafer to be polished using a polishing liquid composition containing silica particles, a water-soluble polymer B, a nitrogen-containing basic compound, and an aqueous medium;
A rinsing step of rinsing the polished silicon wafer using the rinsing agent composition according to any one of claims 1 to 6;
And a cleaning process for cleaning the rinsed silicon wafer.
The water-soluble polymer B is
It consists of the water-soluble polymer, silica particles, water, and hydrochloric acid or ammonia as necessary. The concentration of the water-soluble polymer is 0.01% by mass, the concentration of the silica particles is 0.1% by mass, 25 A zeta potential z of a water-soluble polymer-containing silica aqueous dispersion (aqueous dispersion s) having a pH of 10.0 at 0 ° C., silica particles, water, and optionally hydrochloric acid or ammonia, Water solubility in which the difference (z−z 0 ) from the zeta potential z 0 of a silica aqueous dispersion (aqueous dispersion s 0 ) having a concentration of 0.1% by mass and a pH of 10.0 at 25 ° C. is 15 mV or more The method for producing a silicon wafer according to claim 9, which is a polymer B.
The water-soluble polymer B is
The ratio (D / D 0 ) between the secondary particle diameter D of the silica particles in the aqueous dispersion s and the secondary particle diameter D 0 of the silica particles in the aqueous dispersion s 0 is 1.10 or more. The method for producing a silicon wafer according to claim 10, which is a water-soluble polymer.
The water-soluble polymer B is at least one selected from the group consisting of polysaccharides, alkylacrylamide polymers, polyvinyl alcohol, and polyvinyl alcohol derivatives (excluding anion-modified polyvinyl alcohol). 11. A method for producing a silicon wafer according to any one of items 11.
The water-soluble polymer B is hydroxyethyl cellulose;
The method for producing a silicon wafer according to claim 9, wherein the water-soluble polymer A is a polyglycerin derivative.
The method for manufacturing a silicon wafer according to any one of claims 9 to 13, wherein, in the rinsing step, a water rinsing process using water as a rinsing liquid is performed before the rinsing process.
The method for manufacturing a silicon wafer according to any one of claims 9 to 14, wherein the rinsing process in the rinsing process is performed using a polishing apparatus used in the polishing process.
A method for producing a semiconductor substrate, comprising a step of producing a silicon wafer by the method for producing a silicon wafer according to any one of claims 9 to 15.