KR20230082604A - Polishing liquid composition for silicon substrate - Google Patents

Abstract

In one aspect, a polishing liquid composition for a silicon substrate capable of achieving both improvement in polishing rate and storage stability of a concentrate is provided. In one aspect, the present disclosure relates to a polishing liquid composition for a silicon substrate, which contains the following component A and the following component B, and has a pH greater than 8.5 and 14 or less.
Component A: Silica particles
Component B: Amino group-containing water-soluble polymer having a pKa of 5 or more and 8.5 or less

Description

Polishing liquid composition for silicon substrate

The present disclosure relates to a polishing liquid composition for a silicon substrate, a polishing method using the same, and a method for manufacturing a semiconductor substrate.

As a polishing liquid composition used for polishing silicon substrates used in the manufacture of semiconductor substrates, a polishing liquid composition containing silica particles is known. In this type of polishing liquid composition, there are problems with the occurrence of surface defects (LPD: Light point defects) of the silicon substrate due to the aggregation of silica particles and filter clogging when filtering the polishing liquid composition to remove the aggregates. (See, for example, Japanese Unexamined Patent Publication No. 2008-53415). In addition, for the purpose of improving the polishing rate, a polishing liquid composition containing a water-soluble polymer compound is known (see Japanese Unexamined Patent Publication Nos. 2007-19093 and 11-116942).

Japanese Unexamined Patent Publication No. 2008-53415 proposes a polishing liquid composition containing at least one type of water-soluble polymer selected from polyvinylpyrrolidone and polyN-vinylformamide and an alkali in order to reduce LPD.

In Japanese Unexamined Patent Publication No. 2007-19093, a polishing liquid composition containing a water-soluble high molecular compound containing a nitrogen-containing group such as polyethyleneimine is proposed.

In Japanese Unexamined Patent Publication No. 11-116942, a polishing liquid composition containing hydroxyethyl cellulose (HEC) is proposed for improving the polishing speed and improving the wettability of the surface of an object to be polished.

In one aspect, the present disclosure relates to a polishing liquid composition for a silicon substrate, which contains the following component A and the following component B, and has a pH greater than 8.5 and 14 or less.

Component A: Silica particles

Component B: Amino group-containing water-soluble polymer having a pKa of 5 or more and 8.5 or less

In one aspect, the present disclosure relates to a method for polishing a silicon substrate, including a step of polishing a silicon substrate to be polished using the polishing liquid composition of the present disclosure.

In one aspect, the present disclosure relates to a method for manufacturing a semiconductor substrate, including a step of polishing a silicon substrate to be polished using the polishing liquid composition of the present disclosure, and a step of cleaning the polished silicon substrate.

However, in the polishing using the polishing liquid composition of Unexamined-Japanese-Patent No. 2008-53415, it cannot be said that the polishing rate is sufficient.

When the polishing liquid composition of Japanese Laid-open Patent Publication No. 2007-19093 is used, there is a problem that silica particles are aggregated by a water-soluble polymer compound containing a nitrogen-containing group, and the surface state of the silicon substrate is deteriorated, such as occurrence of scratches.

When the polishing liquid composition containing HEC of Japanese Unexamined Patent Publication No. 11-116942 is used, aggregates of silica particles are easily formed, and even filtering the polishing liquid composition immediately causes filter clogging. Therefore, the polishing liquid composition is filtered immediately before polishing. I have a problem that I can't.

In addition, usually, the polishing liquid composition is stored and transported in a concentrate state, and storage stability in the concentrate is also required.

The present disclosure provides a polishing liquid composition for a silicon substrate capable of achieving both an improvement in polishing rate and storage stability of a concentrate, a method for polishing a silicon substrate using the same, and a method for manufacturing a semiconductor substrate.

The present disclosure, by using a polishing liquid composition for a silicon substrate containing silica particles and a water-soluble polymer containing an amino group having a pKa of 5 or more and 8.5 or less, and having a pH of more than 8.5 and 14 or less, can polish a silicon substrate at high speed, and the storage stability of the concentrate It is based on the knowledge that this is excellent.

That is, the present disclosure, in one aspect, contains the following component A and the following component B, and the pH is more than 8.5 and 14 or less, in a polishing liquid composition for a silicon substrate (hereinafter also referred to as "polishing liquid composition of the present disclosure") it's about

Component A: Silica particles

Component B: Amino group-containing water-soluble polymer having a pKa of 5 or more and 8.5 or less

According to the present disclosure, in one or more embodiments, it is possible to provide a polishing liquid composition for a silicon substrate capable of achieving both an improvement in polishing rate and storage stability of a concentrate.

Although the details of the effect expression mechanism of this indication are not clear, it guesses as follows.

Under alkaline polishing conditions with a pH of more than 8.5 and 14 or less, both the silica abrasive grain and the polished silicon substrate have a negative charge, and electrostatic repulsive force is always generated. In order to improve the polishing rate, it is effective to alleviate this electrostatic repulsive force, and the negative charge on both surfaces can be alleviated by a cationic substance, but if so, aggregation between silica particles occurs, storage stability of the polishing liquid composition, In particular, a new subject that the storage stability of the concentrate of the polishing liquid composition is lowered will occur.

Therefore, as a result of paying attention to the water-soluble polymer having an amino group, the amino group-containing water-soluble polymer (component B) having a pKa smaller than the pH of the abrasive composition has low cationicity, and has a low amino group relative to the silica particles (component A) or the silicon substrate to be polished. It is thought to be adsorbed by the van der Waals force of the entire molecule as the main factor rather than the electrostatic interaction with . Therefore, it is considered that the electrostatic repulsive force between the silica particles (component A) and the silicon substrate to be polished is moderately alleviated, and aggregation of the silica particles is suppressed, so that both the improvement in the polishing rate and the storage stability can be achieved.

However, this disclosure does not have to be construed as being limited to these mechanisms.

[Silicon substrate to be polished]

The polishing liquid composition of the present disclosure is a polishing composition for a silicon substrate, and is, for example, a polishing step of polishing a silicon substrate to be polished in a method for manufacturing a semiconductor substrate or a silicon substrate to be polished in a method for polishing a silicon substrate. It can be used in the polishing process of polishing. Examples of the silicon substrate to be polished using the polishing liquid composition of the present disclosure include, in one or more embodiments, a silicon substrate and the like, and in one or more embodiments, a single crystal silicon substrate and polysilicon. A substrate, a substrate having a polysilicon film, a SiN substrate, and the like, from the viewpoint of exhibiting the effect of the polishing liquid composition of the present disclosure, a single crystal silicon substrate or a polysilicon substrate is preferable, and a single crystal silicon substrate is more preferable.

[Silica Particles (Component A)]

The polishing liquid composition of the present disclosure contains silica particles (hereinafter also referred to as “component A”) as an abrasive. Examples of component A include colloidal silica, fumed silica, pulverized silica, and silica surface-modified thereof. From the viewpoint of achieving both improvement in polishing rate and storage stability, surface roughness (haze), surface defects and scratches Colloidal silica is preferable from the viewpoint of improving surface quality such as reduction of . Component A may be one type or a combination of two or more types.

As a usage form of component A, a slurry form is preferable from a viewpoint of operativity. When component A contained in the polishing liquid composition of the present disclosure is colloidal silica, from the viewpoint of preventing contamination of the silicon substrate by alkali metals, alkaline earth metals, etc., the colloidal silica is obtained from a hydrolyzate of alkoxysilane. desirable. The silica particle obtained from the hydrolyzate of an alkoxysilane can be manufactured by a conventionally well-known method.

The average primary particle size of component A is preferably 10 nm or more, more preferably 20 nm or more, still more preferably 30 nm or more, from the viewpoint of maintaining the polishing rate, and from the viewpoint of improving storage stability and surface 50 nm or less is preferable, 45 nm or less is more preferable, and 40 nm or less is still more preferable from the viewpoint of improving surface quality such as roughness (haze), reduction of surface defects and scratches. From the same viewpoint, the average primary particle diameter of component A is preferably 10 nm or more and 50 nm or less, more preferably 20 nm or more and 45 nm or less, and still more preferably 30 nm or more and 40 nm or less.

In the present disclosure, the average primary particle size of component A is calculated using the specific surface area S (m 2 /g) calculated by the nitrogen adsorption method (BET method). The value of the average primary particle size is a value measured by the method described in Examples.

The average secondary particle size of component A is preferably 20 nm or more, more preferably 30 nm or more, still more preferably 40 nm or more, and even more preferably 60 nm or more, from the viewpoint of maintaining the polishing rate. 100 nm or less is preferable, 90 nm or less is more preferable, and 80 nm or less is still more preferable from the viewpoint of improving and surface quality such as reduction of surface roughness (haze), surface defects and scratches. From the same viewpoint, the average secondary particle diameter of component A is preferably 20 nm or more and 100 nm or less, more preferably 40 nm or more and 90 nm or less, and still more preferably 60 nm or more and 80 nm or less.

In the present disclosure, the average secondary particle size is a value measured by a dynamic light scattering (DLS) method, and is a value measured by the method described in Examples.

The degree of association of component A is preferably 3 or less, more preferably 2.5 or less, still more preferably 2.3 or less, from the viewpoints of improving storage stability and improving surface quality, and improving the polishing rate and From the viewpoint of achieving both storage stability and improving surface quality, 1.1 or more is preferable, 1.5 or more is more preferable, and 1.8 or more is still more preferable.

In the present disclosure, the degree of association of component A is a coefficient representing the shape of silica particles, and is calculated by the following formula.

Degree of association = average secondary particle size/average primary particle size

As a method for adjusting the degree of association of component A, for example, Japanese Unexamined Patent Publication No. 6-254383, Japanese Unexamined Patent Publication No. Hei 11-214338, Japanese Unexamined Patent Publication No. Hei 11-60232, Japanese Unexamined Patent Publication No. 2005 Methods described in No. -060217, Japanese Unexamined Patent Publication No. 2005-060219 and the like can be employed.

The shape of component A is preferably a so-called spherical shape and/or a so-called cocoon shape from the viewpoints of achieving both improvement in polishing rate and storage stability and improving surface quality.

The content of component A in the polishing liquid composition of the present disclosure is preferably 0.01 mass% or more, more preferably 0.05 mass% or more, and still more preferably 0.07 mass% or more in terms of SiO ₂ from the viewpoint of improving the polishing rate. And, from the viewpoints of improving storage stability and improving surface quality, the content is preferably 2.5% by mass or less, more preferably 1% by mass or less, and still more preferably 0.8% by mass or less. Therefore, the content of component A in the polishing liquid composition of the present disclosure is preferably 0.01 mass% or more and 2.5 mass% or less, more preferably 0.05 mass% or more and 1 mass% or less, and more preferably 0.07 mass% or more and 0.8 mass% or less. desirable. When component A is a combination of two or more types, the content of component A refers to their total content.

Further, when the silicon substrate to be polished is a single crystal silicon substrate, the content of component A in the polishing liquid composition of the present disclosure is more preferably 0.5% by mass or less from the viewpoints of improving storage stability and improving surface quality. And, 0.3 mass% or less is more preferable, and 0.2 mass% or less is still more preferable. Therefore, the content of component A in the polishing liquid composition of the present disclosure is more preferably 0.07 mass% or more and 0.5 mass% or less, still more preferably 0.07 mass% or more and 0.3 mass% or less, and is 0.07 mass% or more and 0.2 mass%. The following is more preferable.

Further, when the silicon substrate to be polished is a polysilicon substrate, the content of component A in the polishing liquid composition of the present disclosure is more preferably 0.1% by mass or more, and more preferably 0.2% by mass or more, from the viewpoint of improving the polishing rate. It is more preferable, and 0.3 mass % or more is even more preferable. Therefore, the content of component A in the polishing liquid composition of the present disclosure is more preferably 0.1% by mass or more and 0.8% by mass or less, more preferably 0.2% by mass or more and 0.8% by mass or less, and is 0.3% by mass or more and 0.8% by mass. The following is more preferable.

[Amino group-containing water-soluble polymer having a pKa of 5 or more and 8.5 or less (component B)]

The polishing liquid composition of the present disclosure contains an amino group-containing water-soluble polymer (hereinafter also referred to as "component B") having a pKa of 5 or more and 8.5 or less. Component B is capable of suppressing aggregation of silica particles while reducing the electrostatic repulsive force between the silica particles (component A) and the silicon substrate to be polished by adjusting the zeta potential of the silica particles (component A) and the silicon substrate to be polished. I think. In the present disclosure, “water-soluble” means a solubility of 0.5 g/100 mL or more, preferably 2 g/100 mL or more, in water (20° C.).

The pKa of component B is 5 or more, preferably 5.5 or more, more preferably 5.9 or more, still more preferably 6.3 or more, from the viewpoint of improving the polishing rate, and 8.5 or less from the viewpoint of improving the surface quality. As , 8.3 or less is preferable, 8.1 or less is more preferable, and 8 or less is still more preferable.

Further, when component B is component B1 described later, the pKa of component B is more preferably 6.5 or more from the viewpoint of improving the polishing rate, and more preferably 7.7 or less from the viewpoint of improving surface quality, 7.4 or less is more preferable, and 7.1 or less is still more preferable.

Further, when component B is component B2 described later, the pKa of component B is more preferably 6.6 or more, more preferably 6.9 or more, still more preferably 7.1 or more, from the viewpoint of improving the polishing rate, and the surface From the viewpoint of improving the quality, 7.8 or less is more preferable, 7.6 or less is more preferable, and 7.4 or less is still more preferable.

Component B preferably contains a structural unit derived from at least one monomer selected from allylamine and diallylamine from the viewpoint of achieving both an improvement in polishing rate and storage stability. From the viewpoint of availability, in one or more embodiments, component B is preferably an amino group-containing water-soluble polymer (hereinafter also referred to as "component B1") containing a structural unit derived from allylamine, and one or more In the embodiment, it is preferably an amino group-containing water-soluble polymer (hereinafter also referred to as "component B2") containing a constitutional unit derived from diallylamine.

(Component B1: Amino group-containing water-soluble polymer containing structural units derived from allylamine)

In one or more embodiments, at least a part of the amino group in the allylamine-derived structural unit preferably has a steric blocking group from the viewpoint of achieving both improvement in polishing rate and storage stability and availability. In the present disclosure, the steric blocking group refers to a steric (bulky) substituent capable of suppressing cationization by blocking the nitrogen atom of the amino group of component B, that is, lowering the pKa. From the same viewpoint, the amino group having a steric blocking group is preferably a secondary amino group or a tertiary amino group containing a hydrocarbon group having 3 to 11 carbon atoms and having a hydroxyl group. The number of carbon atoms in the hydrocarbon group is preferably 3 or more from the viewpoint of improving the shielding properties of the amino group (suppressing the cationization of the nitrogen atom of the amino group) and from the viewpoint of achieving both the improvement of the polishing rate and the storage stability, and the water-soluble From the viewpoint of improvement and availability, 11 or less is preferable, 7 or less is more preferable, 5 or less is still more preferable, and 4 or less is still more preferable.

In one or more embodiments, the amino group having a steric blocking group is a group modified by a glycidol derivative for the amino group, and in one or more embodiments, the amino group and glycidol in allylamine-derived structural units A group formed by the reaction of a derivative. At least a part of all amino groups of component B1 is denatured with a glycidol derivative to become an amino group having a sterically blocked group. The equivalent weight of the glycidol derivative relative to the number of amino groups (1 equivalent) in allylamine-derived structural units (hereinafter also referred to as "glycidol modification rate") is from the viewpoint of improving storage stability and surface quality. In , 0.3 or more is preferable, 0.5 or more is more preferable, 0.8 or more is still more preferable, 1 or more is still more preferable, more than 1.1 is preferable, 1.2 or more is more preferable, 1.3 or more is more preferable, and 1.4 The above is more preferable, 1.5 or more is more preferable, and from the viewpoint of improving the polishing rate, 4 or less is preferable, 3 or less is more preferable, 2.5 or less is still more preferable, 2 or less is still more preferable, 1.9 or less is more preferable, and 1.6 or less is still more preferable.

In the present disclosure, the glycidol denaturation rate is a value measured by the method described in Examples using ¹³ C-NMR. However, the glycidol modification rate can also be measured by the following method (1) or (2).

(1) It can be obtained from the amino group equivalent of the allylamine polymer used as the reaction raw material and the number of moles of the glycidol derivative.

(2) Nitrogen content N (mass %) of the reaction product of a glycidol derivative and an allylamine polymer is measured, and it can obtain|require from the following formula.

Glycidol denaturation rate = A/B

Here, A = (100 - N x molecular weight of allylamine monomer/14)/molecular weight of glycidol derivative, and B = N/14.

As a glycidol derivative, glycidol, an alkyl glycidyl ether, etc. are mentioned, for example, From a viewpoint of availability and the viewpoint of making the improvement of polishing rate and storage stability compatible, glycidol is preferable. The alkyl group of the alkyl glycidyl ether is preferably an alkyl group having 1 to 8 carbon atoms from the viewpoint of availability, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, and a 2-ethylhexyl group. As a specific example of alkyl glycidyl ether, methyl glycidyl ether, 2-ethylhexyl glycidyl ether, etc. are mentioned.

As component B1, in one or more embodiments, polyallylamine in which at least a part of the amino group has a steric blocking group is exemplified. In one or more embodiments, a reaction product of polyallylamine and a glycidol derivative is can be heard

As component B1, in one or more embodiments, the compound (glycidol-modified polyallylamine) containing the structural unit of following formula (I) is mentioned, for example.

[Formula 1]

In formula (I), R ¹ and R ² are each a hydrogen atom or a steric blocking group. Examples of the steric masking group include a modifier derived from a glycidol derivative, and in one or more embodiments, a 1-mol adduct or a 2-mol adduct of glycidol can be used. In the form, -CH ₂ CH(OH)CH ₂ (OH), -CH ₂ CH(OH)CH ₂ O-CH ₂ CH(OH)CH ₂ (OH) and the like.

(Component B2: amino group-containing water-soluble polymer containing structural units derived from diallylamine)

In one or more embodiments, at least a part of the amino group in the diallylamine-derived structural unit preferably has an electron withdrawing group at the β-position or γ-position of the amino group from the viewpoint of achieving both improvement in polishing rate and storage stability. do. As an electron withdrawing group, the group etc. represented by following formula (II) are mentioned.

[Formula 2]

Component B2, in one or more embodiments, includes a compound containing a structural unit derived from diallylamine and a structural unit derived from sulfur dioxide, for example, a structural unit represented by the following formula (III) Compounds that do.

[Formula 3]

In Formula (III), R ³ is an alkyl group having 1 to 3 carbon atoms which may have a hydroxyl group. From the viewpoints of availability and economy, R ³ is preferably a methyl group. Moreover, n + m = 1, and n and m are 0 or 1. From the same point of view, a compound in which m = 1 and n = 0 is preferable. In addition, a mixture of a compound of m = 1 and n = 0 and a compound of m = 0 and n = 1 may be used.

As component B2, in one or more embodiment, the compound containing the structural unit represented by following formula (IV) is mentioned, For example, a methyldiallylamine/sulfur dioxide copolymer is mentioned.

[Formula 4]

The weight average molecular weight of component B is preferably 800 or more, more preferably 1,000 or more, still more preferably 1,500 or more, and still more preferably 2,000 or more, from the viewpoint of improving the polishing rate. From the viewpoints of achieving both storage stability and reducing surface roughness and surface defects, it is preferably 100,000 or less, more preferably 50,000 or less, further preferably 30,000 or less, still more preferably 20,000 or less, and still more preferably 15,000 or less. It is preferable, and 12,000 or less is more preferable. The weight average molecular weight of component B in the present disclosure can be measured, for example, by the method described in Examples.

When component B is component B1, the weight average molecular weight of component B is preferably 800 or more, more preferably 1,000 or more, still more preferably 1,500 or more, still more preferably 2,000 or more, from the viewpoint of improving the polishing rate. , 3,000 or more is preferable, 5,000 or more is more preferable, 6,000 or more is more preferable, and 7,000 or more is still more preferable, and the viewpoint of achieving both improvement in polishing rate and storage stability, reducing surface roughness and surface defects From the viewpoint, it is preferably 100,000 or less, more preferably 50,000 or less, still more preferably 30,000 or less, still more preferably 20,000 or less, still more preferably 15,000 or less, still more preferably 12,000 or less, and still more preferably 10,000 or less. .

When component B is component B2, the weight average molecular weight of component B is preferably 800 or more, more preferably 1,000 or more, still more preferably 1,500 or more, still more preferably 2,000 or more, from the viewpoint of improving the polishing rate. And, from the viewpoint of achieving both improvement in polishing rate and storage stability, and from the viewpoint of reducing surface roughness and surface defects, 100,000 or less is preferable, 50,000 or less is more preferable, 30,000 or less is still more preferable, and 20,000 or less is more preferably 15,000 or less, more preferably 12,000 or less, still more preferably 10,000 or less, still more preferably 7,000 or less, still more preferably 5,000 or less, and still more preferably 4,000 or less.

The content of component B in the polishing liquid composition of the present disclosure is preferably 10 ppm by mass or more, more preferably 20 ppm by mass or more, and still more preferably 30 ppm by mass or more, from the viewpoint of achieving both improvement in polishing rate and storage stability. And, from the same viewpoint, 200 mass ppm or less is preferable, 150 mass ppm or less is more preferable, and 120 mass ppm or less is still more preferable. In addition, in this indication, 1 mass % is 10,000 mass ppm (the same hereinafter).

The ratio of the content of component B to the content of component A in the polishing liquid composition of the present disclosure (mass ratio B/A) is preferably 0.008 or more, more preferably 0.016 or more, from the viewpoint of improving storage stability, 0.025 or more is more preferable, and from the viewpoint of improving the polishing rate, 0.16 or less is preferable, 0.12 or less is more preferable, and 0.09 or less is still more preferable.

[water]

The polishing liquid composition of the present disclosure may contain water in one or more embodiments. As water, water, such as ion-exchanged water and ultrapure water, is mentioned, for example. The content of water in the polishing liquid composition of the present disclosure can be, for example, the remainder of component A, component B, and optional components described later.

[Nitrogen-Containing Basic Compound (Component C)]

The polishing liquid composition of the present disclosure, in one or more embodiments, preferably further contains a nitrogen-containing basic compound (hereinafter also referred to as "component C") from the viewpoint of adjusting the pH. As component C, it is preferable that it is a water-soluble nitrogen-containing basic compound from a viewpoint of making the improvement of a polishing rate and storage stability compatible, and a viewpoint of improving surface quality. In the present disclosure, “water-soluble” means a solubility of 0.5 g/100 mL or more, preferably 2 g/100 mL or more, in water (20° C.). In the present disclosure, "water-soluble nitrogen-containing basicity" refers to a nitrogen-containing compound that exhibits basicity when dissolved in water. Component C, in one or more embodiments, does not contain an amino group-containing water-soluble polymer (component B). Component C may be one type or a combination of two or more types.

As component C, in one or more embodiment, at least 1 sort(s) chosen from an amine compound and an ammonium compound is mentioned. As component C, 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, Monoisopropanolamine, diisopropanolamine, triisopropanolamine, ethylenediamine, hexamethylenediamine, piperazine hexahydrate, anhydrous piperazine, 1-(2-aminoethyl)piperazine, N-methylpiperazine, diethylenetriamine , tetramethylammonium hydroxide, and 1 type or a combination of 2 or more types selected from hydroxyamine. Especially, as component C, ammonia or a mixture of ammonia and hydroxyamine is preferable, and ammonia is more preferable as component C from a viewpoint of making the improvement of polishing rate and storage stability compatible.

When the polishing liquid composition of the present disclosure contains component C, the content of component C in the polishing liquid composition of the present disclosure is preferably 5 ppm by mass or more, and more preferably 10 ppm by mass or more, from the viewpoint of improving the polishing rate. 20 mass ppm or more is more preferable, and 500 mass ppm or less is preferable, and 300 mass ppm or less is more preferable from the viewpoint of improving storage stability, surface quality, and suppressing corrosion of the silicon substrate. It is preferable, 150 mass ppm or less is more preferable, and 100 mass ppm or less is still more preferable. From the same viewpoint, the content of component C in the polishing liquid composition of the present disclosure is preferably 5 ppm by mass or more and 500 ppm by mass or less, more preferably 10 ppm by mass or more and 300 ppm by mass or less, and 20 ppm by mass or more and 150 ppm by mass or less. More preferably, it is 20 mass ppm or more and 100 mass ppm or less. When component C is a combination of 2 or more types, the content of component C refers to their total content.

When the polishing liquid composition of the present disclosure contains component C, the ratio C/A (mass ratio C/A) of the content of component C to the content of component A in the polishing liquid composition of the present disclosure improves the polishing rate. 0.002 or more is preferable, 0.01 or more is more preferable, 0.015 or more is still more preferable, and 0.025 or more is still more preferable, and from the viewpoint of improving storage stability, surface quality, and silicon substrate From the viewpoint of suppressing the corrosion of , 1 or less is preferable, 0.5 or less is more preferable, 0.1 or less is still more preferable, and 0.08 or less is still more preferable. From the same viewpoint, the mass ratio C/A in the polishing liquid composition of the present disclosure is preferably 0.002 or more and 1 or less, more preferably 0.01 or more and 0.5 or less, still more preferably 0.015 or more and 0.1 or less, and 0.025 or more and 0.08 or less. more preferable

[Other Ingredients]

The polishing liquid composition of the present disclosure may further contain other components as long as the effects of the present disclosure are not hindered. As the other components, in one or more embodiments, water-soluble polymers other than component B, pH adjusters other than component C, preservatives, alcohols, chelating agents, oxidizing agents, and the like are exemplified.

[pH]

The pH of the polishing liquid composition of the present disclosure is greater than 8.5, preferably 9 or more, more preferably 9.5 or more, still more preferably 10 or more, from the viewpoint of achieving both improvement in polishing rate and storage stability. From the viewpoint of improving the quality, it is 14 or less, preferably 13 or less, more preferably 12.5 or less, still more preferably 12 or less, still more preferably 11.5 or less, and still more preferably 11 or less. From the same viewpoint, the pH of the polishing liquid composition of the present disclosure is more than 8.5 and 14 or less, more preferably 9 or more and 13 or less, still more preferably 9 or more and 12.5 or less, still more preferably 9 or more and 12 or less, and 9.5 or more and 11.5 The following is more preferable, and 10 or more and 11 or less are still more preferable. The pH of the polishing liquid composition of the present disclosure can be adjusted using component C or a known pH adjuster. In the present disclosure, the pH is a value measured by the method described in Examples.

[pH - pKa]

The pH of the polishing liquid composition of the present disclosure is preferably greater than the pKa of component B from the viewpoint of achieving both improvement in polishing rate and storage stability and improving surface quality. Specifically, the difference between pH and pKa (pH - pKa) is preferably greater than 0, more preferably 0.5 or more, still more preferably 1 or more, and more preferably 1.5 from the viewpoint of achieving both improvement in polishing rate and storage stability. More than 7 is more preferable, 2 or more is more preferable, 2.5 or more is still more preferable, and from the viewpoint of improving the surface quality, 7 or less is preferable, 6 or less is more preferable, 5.5 or less is still more preferable, 5 or less is more preferable, 4.5 or less is more preferable, 4 or less is still more preferable, and 3.5 or less is still more preferable.

The polishing liquid composition of the present disclosure can be prepared by mixing, for example, components A and B, and, if desired, water, component C, and other components by a known method. That is, the polishing liquid composition of the present disclosure can be produced by, for example, blending at least component A and component B. Accordingly, the present disclosure, in another aspect, relates to a method for producing a polishing liquid composition including a step of blending at least component A and component B. In the present disclosure, "mixing" includes mixing component A, component B, and, if necessary, water, component C, and other components simultaneously or in an arbitrary order. The mixing may be performed using, for example, a homomixer, a homogenizer, an ultrasonic dispersion machine, a wet ball mill, or a stirrer such as a bead mill. The preferred blending amount of each component in the manufacturing method of the polishing liquid composition of the present disclosure can be the same as the preferred content of each component in the polishing liquid composition of the present disclosure described above.

In the present disclosure, "the content of each component in the polishing liquid composition" refers to the content of each component at the time of use, that is, at the time of starting use of the polishing liquid composition for polishing.

The polishing liquid composition of the present disclosure may be prepared as a concentrate and diluted at the time of use, from the viewpoint of storage and transportation. The dilution ratio is preferably 2 times or more, more preferably 10 times or more, still more preferably 30 times or more, still more preferably 50 times or more, from the viewpoints of manufacturing and transportation costs and storage stability. , From the viewpoint of storage stability, it is preferably 180 times or less, more preferably 140 times or less, even more preferably 100 times or less, still more preferably 70 times or less. The concentrate of the polishing liquid composition of the present disclosure can be diluted with water so that the content of each component at the time of use becomes the above-mentioned content (ie, the content at the time of use). In the present disclosure, "when in use" of the concentrate of the polishing liquid composition refers to a state in which the concentrate of the polishing liquid composition is diluted.

[Polishing Fluid Kit]

In another aspect, the present disclosure relates to a polishing liquid kit (hereinafter also referred to as “the kit of the present disclosure”) for producing the polishing liquid composition of the present disclosure. According to the kit of the present disclosure, a polishing liquid composition capable of achieving both an improvement in polishing rate and storage stability of the concentrate is obtained.

As the kit of the present disclosure, in one or more embodiments, an abrasive liquid kit containing a solution containing component A, component B, and component C is exemplified. The said solution may contain the other components mentioned above as needed. The solution may be diluted with water as needed at the time of use.

[Polishing method of silicon substrate]

The present disclosure, in another aspect, includes a step of polishing a silicon substrate to be polished using the polishing liquid composition of the present disclosure (hereinafter, also referred to as a "polishing step"), a method for polishing a silicon substrate (hereinafter, " It is also referred to as "the polishing method of the present disclosure"). According to the polishing method of the present disclosure, since the polishing liquid composition of the present disclosure is used, it is possible to achieve both improvement in polishing rate and improvement in surface quality.

In the polishing step in the polishing method of the present disclosure, for example, the silicon substrate to be polished can be polished with a polishing pressure of 3 to 20 kPa by pressing a surface plate to which a polishing pad is attached. In the present disclosure, the polishing pressure refers to the pressure of a polishing plate applied to the polishing target surface of the polishing target silicon substrate during polishing.

In the polishing step in the polishing method of the present disclosure, for example, a silicon substrate to be polished is pressed against a surface plate to which a polishing pad is attached, and the silicon to be polished is polished at a polishing liquid composition of 15 ° C. or higher and 40 ° C. or lower and the surface temperature of the polishing pad. The substrate can be polished. The temperature of the polishing liquid composition and the surface temperature of the polishing pad are preferably 15 ° C. or higher or 20 ° C. or higher, and 40 ° C. or lower or 30 ° C. The following is preferable.

[Method of manufacturing semiconductor substrate]

In another aspect, the present disclosure includes a step of polishing a silicon substrate to be polished using the polishing liquid composition of the present disclosure (hereinafter also referred to as a "polishing step") and a step of cleaning the polished silicon substrate (hereinafter, It relates to a manufacturing method of a semiconductor substrate (hereinafter also referred to as a "semiconductor substrate manufacturing method of the present disclosure") including a "cleaning step"). According to the semiconductor substrate manufacturing method of the present disclosure, by using the polishing liquid composition of the present disclosure, it is possible to achieve both the improvement in the polishing rate and the storage stability of the concentrate, so that a high-quality semiconductor substrate can be produced in high yield, with good productivity, and at low cost. can be manufactured

The polishing step in the semiconductor substrate manufacturing method of the present disclosure includes, for example, a lapping (rough polishing) step of flattening a single crystal silicon substrate obtained by slicing a single crystal silicon ingot into a thin disc shape, and a lapped single crystal silicon After the substrate is etched, a final polishing step of mirror-finishing the surface of the single-crystal silicon substrate may be included. The polishing liquid composition of the present disclosure is more preferably used in the final polishing step from the viewpoint of achieving both improvement in polishing rate and improvement in surface quality.

In the polishing step in the semiconductor substrate manufacturing method of the present disclosure, for example, a substrate in which a polysilicon film is formed by a chemical vapor deposition (CVD) method on a silicon substrate having a silicon dioxide film and a silicon nitride film is removed from the polysilicon film. and a step of planarizing by simultaneously polishing and planarizing the silicon dioxide film and the silicon nitride film immediately below and the polysilicon film. The polishing liquid composition of the present disclosure is more preferably used in a step of flattening the polysilicon film by removing irregularities from the viewpoint of achieving both improvement in polishing rate and improvement in surface quality.

The polishing step in the semiconductor substrate manufacturing method of the present disclosure is performed under the same conditions (polishing pressure, polishing liquid composition, surface temperature of the polishing pad, etc.) as the polishing step in the polishing method of the present disclosure described above. can

In one or more embodiments, the semiconductor substrate manufacturing method of the present disclosure may include a dilution step of diluting the concentrate of the polishing liquid composition of the present disclosure before the polishing step. As the diluent, water can be used, for example.

In the cleaning step in the semiconductor substrate manufacturing method of the present disclosure, it is preferable to perform inorganic cleaning from the viewpoint of reducing residues on the surface of the silicon substrate. Examples of the cleaning agent used in inorganic cleaning include inorganic cleaning agents containing at least one selected from hydrogen peroxide, ammonia, hydrochloric acid, sulfuric acid, hydrofluoric acid and ozone water.

In one or more embodiments, the method for manufacturing a semiconductor substrate of the present disclosure may further include, after the cleaning step, a step of rinsing the cleaned silicon substrate with water and drying it.

This disclosure further relates to the following one or more embodiments.

<1> contains the following component A and the following component B, and has a pH greater than 8.5, preferably 9 or more, more preferably 9.5 or more, still more preferably 10 or more, and 14 or less, preferably 13 or less; The polishing liquid composition for a silicon substrate, which is more preferably 12.5 or less, more preferably 12 or less, still more preferably 11.5 or less, still more preferably 11 or less.

Component A: Silica particles

Component B: pKa is 5 or more, preferably 5.5 or more, more preferably 5.9 or more, more preferably 6.3 or more, and 8.5 or less, preferably 8.3 or less, more preferably 8.1 or less, more preferably is 8 or less amino group-containing water-soluble polymer

<2> The difference between pH and pKa (pH - pKa) is greater than 0, preferably 0.5 or more, more preferably 1 or more, still more preferably 1.5 or more, still more preferably 2 or more, still more preferably 2.5 or more, and 7 or less, preferably 6 or less, more preferably 5.5 or less, still more preferably 5 or less, still more preferably 4.5 or less, still more preferably 4 or less, still more preferably 3.5 or less, < 1> The polishing liquid composition described in the above.

<3> The polishing liquid composition according to <1> or <2>, wherein the component B contains a structural unit derived from at least one monomer selected from allylamine and diallylamine, preferably diallylamine.

<4> The polishing liquid composition according to <3>, wherein at least a part of the amino groups in the structural units derived from allylamine have a steric blocking group.

<5> The polishing described in <3> or <4>, wherein at least a part of the amino groups in the allylamine-derived structural unit is a secondary amino group or a tertiary amino group containing a hydrocarbon group having 3 or more and 11 or less carbon atoms having a hydroxyl group. liquid composition.

<6> The polishing liquid composition according to any one of <1> to <5>, wherein component B is a reaction product between polyallylamine and a glycidol derivative, preferably a glycidol-modified polyallylamine.

<7> The polishing liquid composition according to <3>, wherein at least a part of the amino groups in the diallylamine-derived structural unit has an electron withdrawing group, preferably a group represented by the following formula (II), at the β-position or the γ-position.

[Formula 5]

<8> The polishing liquid composition according to any one of <1> to <7>, in which component B is a compound containing a structural unit represented by formula (III) below.

[Formula 6]

In formula (III), R ³ is an alkyl group having 1 to 3 carbon atoms which may have a hydroxyl group, preferably a methyl group, and n + m = 1, preferably m = 1 and n = 0.

<9> The ratio of the content of component B to the content of component A in the polishing liquid composition of the present disclosure (mass ratio B/A) is 0.008 or more, preferably 0.016 or more, more preferably 0.025 or more, and , 0.16 or less, preferably 0.12 or less, more preferably 0.09 or less, the polishing liquid composition according to any one of <1> to <8>.

<10> The polishing liquid composition of the present disclosure is a nitrogen-containing basic compound (component C), preferably a water-soluble nitrogen-containing basic compound, more preferably at least one selected from amine compounds and ammonium compounds, still more preferably The polishing liquid composition according to any one of <1> to <9>, containing ammonia.

<11> When the polishing liquid composition of the present disclosure contains component C, the ratio C/A (mass ratio C/A) of the content of component C to the content of component A in the polishing liquid composition of the present disclosure is 0.002 or more, preferably 0.01 or more, more preferably 0.015 or more, still more preferably 0.025 or more, and 1 or less, preferably 0.5 or less, more preferably 0.1 or less, still more preferably 0.08 or less, <10 > The polishing liquid composition described in .

<12> A method for polishing a silicon substrate, including a step of polishing a silicon substrate to be polished using the polishing liquid composition according to any one of <1> to <11>.

<13> The polishing method according to <12>, wherein the silicon substrate to be polished is a single crystal silicon substrate or a polysilicon substrate, preferably a single crystal silicon substrate.

<14> A step of polishing a silicon substrate to be polished using the polishing liquid composition according to any one of <1> to <11>;

A method for manufacturing a semiconductor substrate, comprising a step of cleaning a polished silicon substrate.

Example

Hereinafter, the present disclosure will be described in more detail by examples, but these are exemplary, and the present disclosure is not limited to these examples.

1. Preparation of Polishing Liquid Composition

(Concentrate of Polishing Liquid Composition)

The silica particles (component A) shown in Tables 1 and 2, the water-soluble polymer (component B or non-component B) shown in Tables 1 and 2, ammonia (component C), and ultrapure water were stirred and mixed to obtain a concentrate of the polishing liquid composition ( 60 times) was obtained. The pH of the concentrate at 25°C was 10.6 to 11.0.

(Polishing liquid composition)

The concentrate was diluted 60 times with ion-exchanged water to obtain polishing liquid compositions of Examples 1 to 9 and Comparative Examples 1 to 3. The content of each component in Tables 1 and 2 is the content (mass% or mass ppm, active ingredient) of each component at the time of use of the polishing liquid composition after dilution. The content of ultrapure water is the remainder except for component A and component B or non-component B and component C. The pH of each polishing liquid composition (when used) at 25°C was 10.3.

The pH at 25°C is a value measured using a pH meter (Toa Electric Co., Ltd., HM-30G), and is a value 1 minute after the electrode of the pH meter is immersed in the polishing liquid composition or its concentrate.

The following were used for component A, component B, non-component B and component C used for preparation of each polishing liquid composition.

(component A)

Colloidal silica [average primary particle size 35 nm, average secondary particle size 70 nm, degree of association 2.0]

(component B)

B1: Methyldiallylamine/sulfur dioxide copolymer [manufactured by Nittobo Medical Co., Ltd., PAS-2201, weight average molecular weight 3,000]

B2: glycidol-modified polyallylamine (glycidol modification rate: 2.0) [manufactured by Nittobo Medical Co., Ltd., weight average molecular weight 11,000]

B3: glycidol-modified polyallylamine (glycidol modification ratio: 1.8) [manufactured by Nittobo Medical, weight average molecular weight 10,200]

B4: glycidol-modified polyallylamine (glycidol modification rate: 1.5) [manufactured by Nittobo Medical, weight average molecular weight 8,900]

B5: glycidol-modified polyallylamine (glycidol modification rate: 1.0) [manufactured by Nittobo Medical, weight average molecular weight 6,900]

(non-component B)

B6: allylamine (free) polymer [Nittobo Medical PAA-03, weight average molecular weight 3,000]

B7: polyethyleneimine [manufactured by Nippon Catalyst, SP-200, weight average molecular weight 10,000]

(component C)

Ammonia [28% by mass ammonia water, manufactured by Kishida Chemical Co., Ltd., reagent special grade]

2. How to measure various parameters

(1) Measurement of average primary particle diameter of silica particles (component A)

The average primary particle diameter (nm) of component A was calculated by the following formula using the specific surface area S (m 2 /g) calculated by the BET (nitrogen adsorption) method.

Average primary particle size (nm) = 2727/S

For the specific surface area S of component A, after the following [pretreatment], about 0.1 g of the measurement sample was accurately weighed to 4 decimal places in a measurement cell, and dried for 30 minutes in an atmosphere at 110 ° C. immediately before measuring the specific surface area. Then, it was measured by the nitrogen adsorption method (BET method) using a specific surface area measuring device (micromeritic automatic specific surface area measuring device "Flosorb III2305", manufactured by Shimadzu Corporation).

[Pretreatment]

(a) Component A in the slurry phase is adjusted to pH 2.5 ± 0.1 with an aqueous solution of nitric acid.

(b) A slurry-like component A adjusted to pH 2.5 ± 0.1 is placed in a petri dish, and dried in a hot air dryer at 150°C for 1 hour.

(c) After drying, the obtained sample is finely pulverized with an agate mortar.

(d) The pulverized sample was suspended in ion-exchanged water at 40°C and filtered through a membrane filter having a pore size of 1 µm.

(e) The filtrate on the filter is washed 5 times with 20 g of ion-exchanged water (40°C).

(f) The filter with the filtrate attached is placed in a petri dish and dried for 4 hours in an atmosphere of 110°C.

(g) The dried filtrate (component A) was taken so as not to contain filter debris and finely ground with a pestle to obtain a measurement sample.

(2) average secondary particle diameter of silica particles (component A)

The average secondary particle diameter (nm) of component A was determined by adding the abrasive to ion-exchanged water so that the concentration of component A was 0.25% by mass, and then placing the resulting aqueous dispersion in a Disposable Sizing Cuvette (10 mm cell made of polystyrene) from the lower bottom. It was inserted to a height of 10 mm and measured using a dynamic light scattering method (device name: "Zetasizer Nano ZS", manufactured by Sysmex).

(3) measurement of weight average molecular weight of water-soluble polymer

The weight average molecular weight of the water-soluble polymer (component B, non-component B) was calculated based on a peak in a chromatogram obtained by applying a gel permeation chromatography (GPC) method under the following conditions.

<Measurement conditions of water-soluble polymer>

Device: HLC-8320 GPC (manufactured by Tosoh Corporation, detector integrated)

Column: α-M + α-M

Eluent: 0.15 mol/L Na ₂ SO ₄ , 1 % CH ₃ COOH/water

Flow rate: 1.0 mL/min

Column temperature: 40 ℃

Detector: Shodex RI SE-61 Differential Refractive Index Detector

Standard substance: Monodisperse polyethylene glycol with known molecular weight

(4) Measurement of pKa

Using an HM-41K type pH meter (Toa DKK Co., Ltd.), the aqueous solution of component B adjusted to 1 M was subjected to potentiometric titration with 0.1 M hydrochloric acid at room temperature. pKa was calculated from the obtained titration curve.

(5) Glycidol denaturation rate

The glycidol denaturation rate was determined using ¹³ C-NMR.

<measurement conditions>

Sample: Dissolve 200 mg of glycidol-modified polyallylamine in 0.6 mL of deuterated water.

Apparatus used: 400 MHz ¹³ C-NMR ("Agilent 400-MR DD2" manufactured by Agilent Technology Co., Ltd.)

Measurement conditions: ¹³ C-NMR measurement, pulse interval time 5 seconds, measurement with tetramethylsilane as the standard peak (σ: 0.0 ppm)

Total number of times: 5000 times

Each peak range used for integration:

A: 71.0 to 72.3 ppm (Integral value of peak of C bonded with secondary hydroxyl group of glycidol reacted with amino group)

B: 32.0 to 41.0 ppm (integral value of the peak of the main chain C of allylamine)

<Glycidol denaturation rate>

The glycidol modification rate (ratio of equivalents of glycidol to equivalents of amino groups) is determined by the following formula.

Glycidol denaturation rate (equivalent ratio) = 2A/B

3. Evaluation of the polishing liquid compositions of Examples 1 to 7 and Comparative Examples 1 to 2

(1) Grinding method, etc.

For each polishing liquid composition, filtration was performed with a filter (compact cartridge filter "MCP-LX-C10S", manufactured by Advantech) immediately before polishing, and final polishing and cleaning were performed on the silicon substrate described below under the following polishing conditions. was carried out.

<Silicon substrate to be polished>

Single-crystal silicon substrate [silicon single-side mirror substrate 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]

The single crystal silicon substrate was subjected to rough polishing in advance using a commercially available polishing liquid composition (GLANZOX 1302, manufactured by Fujimi Incorporated). The haze of the single crystal silicon substrate subjected to final polishing after the rough polishing was 2 to 3 ppm.

＜Conditions for finishing polishing＞

Grinding machine: Single-sided 8-inch polishing machine "GRIND-X SPP600s" (manufactured by Okamoto Kogaku)

Polishing pad: suede pad (manufactured by Toray Cotex, Asker hardness: 64, thickness: 1.37 mm, nap length: 450 μm, aperture diameter: 60 μm)

Silicon substrate polishing pressure: 100 g/cm2

Wheel rotation speed: 60 rpm

Polishing time: 5 minutes

Supply rate of polishing liquid composition: 150 g/min

Temperature of polishing liquid composition: 23 ℃

Carrier rotation speed: 62 rpm

<Measurement of surface roughness (haze) of silicon substrate>

A value (DWO haze) in a dark field wide oblique incidence channel (DWO) measured using a surface roughness measuring device "Surfscan SP1-DLS" (manufactured by KLA Tencor) was used.

<Washing method>

After finishing polishing, the silicon substrate 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 rotating silicon substrate at a flow rate of 1 L/min and 600 rpm for 3 minutes. At this time, the temperature of the ozone water was set to room temperature. Next, dilute hydrofluoric acid washing was performed. In dilute hydrofluoric acid cleaning, an aqueous solution containing 0.5% by mass of ammonium bifluoride (Nacalai Tesque Co., Ltd.) was sprayed from a nozzle toward the center of the rotating silicon substrate at a flow rate of 1 L/min and 600 rpm for 6 seconds. A total of two sets of the above ozone cleaning and dilute hydrofluoric acid cleaning were performed, and finally spin drying was performed. In spin drying, the silicon substrate was rotated at 1,500 rpm.

(2) Evaluation of polishing rate

The weight of each silicon substrate 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 substrate, and the single side polishing rate per unit time was determined. Rescued. A result is shown in Table 1. In addition, the weight of the silicon substrate after polishing is the weight of the silicon substrate after performing the final polishing and cleaning.

(3) Evaluation of storage stability of concentrates

100 g of the concentrate of each polishing liquid composition was placed in a 100 ml screw tube and sealed, and the storage stability after 1 day was evaluated according to the following evaluation criteria. The concentrate of the polishing liquid composition was stored in a room at 23°C. A result is shown in Table 1.

<Evaluation Criteria>

A: One day after the concentrate of the polishing liquid composition was prepared, no aggregates and separation occurred, and dispersion stability was maintained.

B: Agglomerates and segregation slightly occurred one day after preparing the concentrate of the polishing liquid composition.

C: Agglomerates and separation occurred one day after preparing the concentrate of the polishing liquid composition.

As shown in Table 1, it was found that the polishing liquid compositions of Examples 1 to 7 were able to achieve both the improvement of the polishing rate and the storage stability of the concentrate compared to the polishing liquid compositions of Comparative Examples 1 and 2.

4. Evaluation of the polishing liquid compositions of Examples 8 to 9 and Comparative Example 3

(1) polishing method

For each polishing liquid composition, filtration was performed with a filter (compact cartridge filter "MCP-LX-C10S", manufactured by Advantech) immediately before polishing, and the following silicon substrate was subjected to the same polishing conditions as in 3 (1) above. After polishing, cleaning was performed by the same cleaning method as in 3 (1) above.

<Silicon substrate to be polished>

On a polysilicon substrate [a silicon single-sided mirror substrate having 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 SiO ₂ film of 4400 Å was deposited by plasma CVD. substrate on which a polysilicon film of 8000 Å was subsequently deposited by the plasma CVD method]

(2) Evaluation of polishing rate

Evaluation of the polishing rate using a polysilicon substrate as a substrate to be polished was evaluated in the same manner as in 3 (2) above. A result is shown in Table 2.

(3) Evaluation of storage stability of concentrates

Evaluation of the storage stability of the concentrate was evaluated in the same manner as in 3 (3) above. A result is shown in Table 2.

As shown in Table 2, it was found that the polishing liquid compositions of Examples 8 and 9 are compatible with the improvement of the polishing rate and the storage stability of the concentrate compared to the polishing liquid composition of Comparative Example 3.

When the polishing liquid composition of the present disclosure is used, both the polishing rate improvement and the storage stability can be achieved. Therefore, the polishing liquid composition of the present disclosure is useful as a polishing liquid composition used in the manufacturing process of various semiconductor substrates, and is particularly useful as a polishing liquid composition for final polishing of silicon substrates.

Claims (10)

Contains the following component A and the following component B,
A polishing liquid composition for a silicon substrate having a pH of greater than 8.5 and 14 or less.
Component A: Silica particles
Component B: Amino group-containing water-soluble polymer having a pKa of 5 or more and 8.5 or less According to claim 1,
The polishing liquid composition in which component B contains structural units derived from at least one monomer selected from allylamine and diallylamine. According to claim 2,
A polishing liquid composition in which at least a part of amino groups in allylamine-derived structural units have a steric blocking group. According to claim 2 or 3,
A polishing liquid composition in which at least a part of the amino groups in allylamine-derived structural units is a secondary amino group or a tertiary amino group containing a hydrocarbon group having 3 to 11 carbon atoms and a hydroxyl group. According to any one of claims 1 to 4,
Component B is a polishing liquid composition that is a reaction product between polyallylamine and a glycidol derivative. According to claim 2,
A polishing liquid composition wherein at least a part of amino groups in diallylamine-derived structural units have an electron withdrawing group at the β-position or the γ-position. The method of any one of claims 1, 2 and 6,
The polishing liquid composition in which component B is a compound containing a structural unit represented by the following formula (III).

In Formula (III), R ³ is an alkyl group having 1 to 3 carbon atoms which may have a hydroxyl group, and n + m = 1. A method for polishing a silicon substrate, comprising a step of polishing a silicon substrate to be polished using the polishing liquid composition according to any one of claims 1 to 7. According to claim 8,
A polishing method wherein the silicon substrate to be polished is a single crystal silicon substrate or a polysilicon substrate. A step of polishing a silicon substrate to be polished using the polishing liquid composition according to any one of claims 1 to 7;
A method for manufacturing a semiconductor substrate, comprising a step of cleaning a polished silicon substrate.