JP6831667B2 - Wetting agent - Google Patents

Description

The present invention relates to a method for polishing a silicon wafer and a method for manufacturing a semiconductor substrate using a wetting agent, a polishing liquid composition for a hydrophobic surface, and a polishing liquid composition for a hydrophobic surface.

In recent years, the design rules of semiconductor devices have been miniaturized due to the increasing demand for higher recording capacities of semiconductor memories. For this reason, the depth of focus becomes shallow in photolithography performed in the manufacturing process of semiconductor devices, and the demand for defect reduction and smoothness of silicon wafers (bare wafers) is becoming more and more strict.

For the purpose of improving the quality of silicon wafers, polishing of silicon wafers is performed in multiple stages. In particular, finish polishing, which is performed in the final stage of polishing, suppresses surface roughness (haze) and improves the wettability (hydrophilization) of the silicon wafer surface after polishing, resulting in surface defects (LPD: Light point) such as particles, scratches, and pits. It is done for the purpose of suppressing defects).

As the polishing liquid composition used for finish polishing, a polishing liquid composition for chemical mechanical polishing using colloidal silica and an alkaline compound is known. For chemical mechanical polishing containing colloidal silica, hydroxyethyl cellulose (HEC) that contributes to improving the wettability of the silicon wafer surface, and polyethylene oxide (PEO) as a polishing liquid composition for further improving the haze level. Abrasive liquid compositions are known (Patent Document 1).

On the other hand, the polishing liquid composition for the purpose of reducing the number of surface defects (LPD) contains a water-soluble cellulose or vinyl polymer that forms a hydrophilic film on the surface of a silicon wafer, and is either sodium ion or acetate ion. A polishing liquid composition having a concentration of 10 ppb or less is known (Patent Document 2). As a polishing liquid composition for improving waviness and / or haze, a chain hydrocarbon polymer having a long carbon chain structure and a hydroxy lower alkoxy group as a side chain, which contributes to the hydrophilicity of the silicon wafer surface ( For example, a polishing liquid composition containing (ethylene oxide-added polyvinyl alcohol) is known (Patent Document 3). As a polishing liquid composition used for flattening the surface of a semiconductor wafer having a step, a polishing liquid composition containing polyvinyl alcohol as a step eliminating agent is known (Patent Document 4). A semiconductor that has excellent adsorptivity to the surface of a silicon wafer and contains polyvinyl acetal obtained by the acetalization reaction of polyvinyl alcohol and an aldehyde compound having 1 to 7 carbon atoms, and is effective in smoothing the wafer surface and suppressing crystal defects (COP). Wetting agents and polishing liquid compositions for use are known (Patent Document 5). As a copolymer composed of a first monomer unit having excellent wettability-imparting properties for a silicon substrate and a second monomer unit having excellent adsorption properties for abrasive particles, for example, PVA-PVP graft copolymer weight. Abrasive liquid compositions containing coalescing are known (Patent Document 6).

As described above, the wettability of the surface to be polished has a great influence on the improvement of the polished surface. Further, in the manufacture of a semiconductor substrate made of a silicon single crystal, it is used for cleaning a polished silicon wafer in order to prevent dust and the like that cause surface defects (LPD) from adhering to the surface of the polished silicon wafer. It is also necessary to be able to impart wettability to the silicon wafer with respect to the rinse liquid composition to be processed, the immersion liquid for temporarily storing the polished silicon wafer in the tank before the target of the next step, and the like.

Further, in order to improve the polishing rate of a hydrophobic surface such as a silicon wafer surface, a siliconized silicon film surface, or a polysilicon film surface, it is necessary that the surface to be polished is wet.

Japanese Unexamined Patent Publication No. 2004-128089 Japanese Unexamined Patent Publication No. 2008-53414 Japanese Unexamined Patent Publication No. 11-14427 WO2011 / 093223 Japanese Unexamined Patent Publication No. 2015-76494 WO2013 / 137212

As described above, in the semiconductor manufacturing process, there are a plurality of steps for ensuring surface wetting.

Further, when polishing a hydrophobic surface such as a silicon wafer surface by using the polishing liquid composition described in the above patent document, a polishing aid having a strong adsorption force to the surface is used in order to improve the wettability of the hydrophobic surface. If it is used, the polishing speed is lowered, so that it is not possible to achieve both reduction of surface defects (LPD) and surface roughness (haze) and improvement of polishing speed.

Therefore, in the present invention, it can be suitably used in various steps of semiconductor manufacturing, and when it is used for polishing a hydrophobic surface, the surface roughness (haze) is reduced, the surface defect (LPD) is reduced, and the polishing speed is reduced. The present invention relates to a method for polishing a silicon wafer and a method for manufacturing a semiconductor substrate using a wetting agent, a polishing liquid composition for a hydrophobic surface, and a polishing liquid composition for a hydrophobic surface, which can be well compatible with the improvement of the above.

The wetting agent of the present invention includes a structural unit I represented by the following general formula (1) and a structural unit II represented by the following general formula (2). However, in the following general formula (2), Z ¹ represents a substituent containing one or more of a nitrogen atom and an oxygen atom.

The polishing liquid composition for a hydrophobic surface of the present invention
Abrasive particles (component A) and
At least one nitrogen-containing basic compound (component B) selected from ammonia, amine compounds and ammonium compounds, and
It contains a polymer compound (component C) containing a structural unit I represented by the following general formula (1) and a structural unit II represented by the following general formula (2).
However, in the above general formula (2), Z ¹ represents a substituent containing one or more of a nitrogen atom and an oxygen atom.

The method for polishing a silicon wafer of the present invention includes a step of polishing a silicon wafer using the polishing liquid composition for a hydrophobic surface of the present invention.

The method for producing a semiconducting substrate of the present invention includes a step of polishing a silicon wafer using the polishing liquid composition for a hydrophobic surface of the present invention.

According to the present invention, it can be suitably used in various manufacturing processes of semiconductors, and when it is used for polishing a hydrophobic surface, it can reduce surface roughness (haze), reduce surface defects (LPD), and improve polishing speed. The present invention relates to a method for polishing a silicon wafer and a method for manufacturing a semiconductor substrate using a wetting agent, a polishing liquid composition for a hydrophobic surface, and a polishing liquid composition for a hydrophobic surface, which can satisfactorily achieve both.

In the present invention, the hydrophobic surface is wetted by containing a polymer compound containing the structural unit I represented by the following general formula (1) and the structural unit II represented by the following general formula (2). When the polymer compound is used for the preparation of a hydrophobic surface polishing liquid composition (hereinafter, may be abbreviated as "polishing liquid composition"), the surface roughness (haze) is reduced. Based on the finding that it is possible to achieve both reduction of surface defects (LPD) and improvement of polishing speed. In the following general formula (2), Z ¹ represents a substituent containing one or more of a nitrogen atom and an oxygen atom.

Although the details of the mechanism for expressing the effects of the present invention are not clear, the applicant presumes as follows.

Since the structural unit I of the polymer compound contained in the wetting agent and the polishing liquid composition of the present invention contains a hydroxyl group which is a site to be adsorbed on the hydrophobic surface, the polymer compound is adsorbed on a hydrophobic surface such as a silicon wafer surface. A layer can be formed to wet the hydrophobic surface. Therefore, when a wetting agent containing the above polymer compound is used for preparing the polishing liquid composition, the above polymer compound is appropriately adsorbed on the hydrophobic surface, and the nitrogen-containing basic compound contained in the polishing liquid composition is used. By suppressing corrosion due to such factors, good surface roughness (haze) is achieved, good wettability is exhibited on the hydrophobic surface, and adhesion of particles due to drying of the hydrophobic surface is suppressed to cause low surface defects. (LPD) is possible. In addition, since the polymer compound is adsorbed on the hydrophobic surface, the wettability of the hydrophobic surface is improved, so that the uniformity of polishing of the hydrophobic surface is improved, which also reduces the surface roughness (haze). It is presumed to be.

Further, it has been known that an alkyl-modified polyvinyl acetal in which polyvinyl alcohol is modified with an aldehyde having an alkyl group has high adsorptivity to a silicon wafer and is effective for smoothing and low defects (see Patent Document 5). However, there is a problem that the polishing rate is slow because the alkyl-modified polyvinyl acetal excessively protects the surface of the silicon wafer. Further, under alkaline conditions, both the surface charges of the silica particles and the silicon wafer are negatively charged, and the silica particles cannot approach the silicon wafer due to the charge repulsion, so that the polishing rate cannot be sufficiently developed. In the present invention, since the constituent unit II of the polymer compound contains a substituent containing at least one atom of nitrogen atom and oxygen atom adsorbed on the silica particles, a wetting agent containing the polymer compound. When used in the preparation of the abrasive liquid composition, the above polymer compound acts as a binder between the silica particles and the hydrophobic surface. As a result, it is considered that the polymer compound (component C) contributes to the improvement of the polishing speed of the silicon wafer.

As described above, the wetting agent of the present invention containing the above polymer compound can be suitably used in various steps in the production of semiconductors, and when used for polishing a hydrophobic surface, surface roughness (haze) and surface defects (haze) and surface defects ( It is possible to achieve both reduction of LPD) and improvement of polishing speed. Further, in the present invention, although the reason is not clear, by containing the above-mentioned polymer compound as a polishing aid, the polishing rate is remarkably faster than in the case of containing an alkyl-modified polyvinyl acetal, and surface defects (LPD) are present. ) Is significantly less.

(Polymer compound)
The polymer compound contained in the wetting agent and the polishing liquid composition of the present invention contains a structural unit I represented by the following general formula (1) and a structural unit II represented by the following general formula (2). .. However, in the following general formula (2), Z ¹ represents a substituent containing one or more of a nitrogen atom and an oxygen atom.

The source of the structural unit I in the polymer compound is polyvinyl alcohol from the viewpoint of availability and easiness of synthesizing the polymer compound.

In the structural unit II, Z ^1, from the viewpoint of easy synthesis of the availability and high molecular compounds, preferably ^{-Y 1 NR 1 R 2, -Y} 1 NHCOR 3, -Y 1 CONHR 4 or - (AO ) M-H, more preferably -Y ¹ NHCOR ³ . Further, from the viewpoint of improving wettability, Z ¹ preferably contains an amide skeleton exhibiting high hydrophilicity (a skeleton containing an amide bond), and polishing when a polymer compound is used in the preparation of a polishing solution composition. From the viewpoint of improving the speed, a substituent containing both a nitrogen atom and an oxygen atom is preferable.

From the viewpoint of easy availability and synthesis of a polymer compound, Y ¹ is preferably an alkylene group having 1 to 4 carbon atoms, more preferably a methylene group or an ethylene group, and further preferably. Is a methylene group.

The R ¹ , R ² , R ³ and R ⁴ are preferably hydrogen atoms or alkyl groups having 1 or more and 4 or less carbon atoms independently from the viewpoint of easy availability and synthesis of polymer compounds. It is more preferably a hydrogen atom, a methyl group or an ethyl group independently, and even more preferably a hydrogen atom or a methyl group.

From the viewpoint of easy availability and synthesis of a polymer compound, the AO is preferably an oxyalkylene group having 2 or more and 4 or less carbon atoms, and more preferably an ethyleneoxy group (EO) or propyleneoxy. It is at least one alkyleneoxy group selected from the group consisting of a group (PO) and a butyleneoxy group (BO), more preferably at least one alkyleneoxy group selected from EO and PO, and even more preferably. Is EO.

The average number of moles of AO added is preferably 1 or more, more preferably 3 or more, still more preferably 5 or more from the viewpoint of improving the polishing rate, and preferably 100 or less, more preferably 5 or more from the same viewpoint. It is 75 or less, more preferably 50 or less.

The ratio of the structural unit I in all the structural units of the polymer compound preferably exceeds 0 mol% from the viewpoint of improving the polishing rate when the polymer compound is used for preparing the polishing liquid composition. It is more preferably 30 mol% or more, further preferably 50 mol% or more, even more preferably 70 mol% or more, and preferably 90 mol% or less, more preferably from the viewpoint of reducing surface defects (LPD). Is 85 mol% or less, more preferably 80 mol% or less.

The ratio of the structural unit II to all the structural units of the polymer compound is preferably 1 mol% or more, from the viewpoint of improving the polishing rate when the polymer compound is used for preparing the polishing liquid composition. It is preferably 5 mol% or more, more preferably 10 mol% or more, still more preferably 15 mol% or more, and from the viewpoint of improving storage stability, reducing surface roughness (haze) and surface defects (LPD). Therefore, it is preferably less than 100 mol%, more preferably 70 mol% or less, still more preferably 50 mol% or less, still more preferably 30 mol% or less, still more preferably 20 mol% or less.

When Z ^{1 of the} structural unit II is an amide-modified polyvinyl acetal containing an amide group, the polymer compound contains an acetal structure exhibiting hydrophobicity and an amide skeleton exhibiting high hydrophilicity, and thus the hydroxyl group contained in the structural unit I. Coupled with this, the polymer compound exhibits high wettability. The acetalization rate of the amide-modified polyvinyl acetal is preferably 1 mol% or more, more preferably 5 mol% or more, and further, from the viewpoint of improving the polishing rate when the polymer compound is used for preparing the polishing liquid composition. It is preferably 10 mol% or more, even more preferably 15 mol% or more, and is preferably 100 mol% from the viewpoint of improving storage stability, reducing surface roughness (haze) and surface defects (LPD). Less than, more preferably 70 mol% or less, still more preferably 50 mol% or less, even more preferably 30 mol% or less, still more preferably 20 mol% or less. For the acetalization rate, the introduction rate of the reactant was calculated using 1H-NMR (manufactured by Agilent Technologies, 400 MHz), and the rate of consumption of OH groups was taken as the acetalization rate.

The polymer compound is represented by the following general formula (3) in addition to the structural unit I and the structural unit II from the viewpoint of improving the polishing rate when the polymer compound is used for preparing the polishing liquid composition. It may include building blocks III.

In the above general formula (3), X ¹ represents a nitrogen atom or an oxygen atom, and n represents a number of 1 or more and 5 or less. X ¹ is preferably a nitrogen atom from the viewpoint of availability and easiness of synthesizing a polymer compound. From the viewpoint of availability and easiness of synthesizing the polymer compound, n is preferably 2 or more and 4 or less, and more preferably 3.

The ratio of the structural unit III to all the structural units of the polymer compound is preferably 0.01 mol% or more from the viewpoint of improving the polishing rate when the polymer compound is used for preparing the polishing liquid composition. , More preferably 0.05 mol% or more, still more preferably 2 mol% or more, and from the viewpoint of storage stability and reduction of surface defects (LPD), preferably 90 mol% or less, more preferably 70 mol. % Or less, more preferably 60 mol% or less, even more preferably 50 mol% or less.

The polymer compound may contain structural units other than the structural units I to III as long as the wettability is not impaired. Examples of the monomer component forming the structural units other than the structural units I to III include acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, styrene, styrenesulfonic acid, vinylpyrrolidone, ethyloxazoline, and polyethylene glycol acrylate. Examples thereof include polyethylene glycol methacrylate, acrylamide, dimethylacrylamide, diethylacrylamide, isopropylacrylamide, hydroxyethylacrylamide and the like.

The total mass ratio of the structural unit I and the structural unit II in all the structural units of the polymer compound is the improvement of the polishing speed and the surface roughness when the polymer compound is used for the preparation of the polishing liquid composition. From the viewpoint of achieving both reduction of haze and surface defects (LPD), it is preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, still more preferably 50% by mass or more. It is even more preferably 80% by mass or more, even more preferably substantially 100% by mass, and even more preferably 100% by mass.

The arrangement of each structural unit in the polymer compound may be block or random.

The weight average molecular weight of the polymer compound is preferably 1,000 or more, more preferably 10,000 or more, still more preferably 10,000 or more, from the viewpoint of improving the polishing rate when the polymer compound is used in the preparation of the polishing liquid composition. Is 20,000 or more, more preferably 50,000 or more, and from the viewpoint of easiness of synthesizing the polymer compound, preferably 500,000 or less, more preferably 200,000 or less, still more preferably 100. It is less than 000. The weight average molecular weight of the polymer compound can be measured, for example, by the method described in Examples.

(Manufacturing method of polymer compound)
An example of the polymer compound in the present invention can be obtained, for example, by subjecting polyvinyl alcohol and an acetamide compound to a dehydration condensation reaction in the presence of an acid catalyst to modify a part of the hydroxyl groups of polyvinyl alcohol into acetal groups. .. The hydroxyl group can be acetalized by a conventionally known method.

Examples of the acetamide compound include N- (2,2-dimethoxyethyl) acetamide, N-methyl-N- (2,2-dimethoxyethyl) acetamide, N- (4,4-dimethoxybutyl) acetamide, and N-( 3,3-Dimethoxypropyl) acetamide, N, N-dimethoxyacetamide, N-methyl-N- (2,2-dimethoxyethyl) -2-aminoacetamide, N, N-diethyl-2,2-dimethoxyacetamide, etc. Can be mentioned. The acetamide compound is preferably more than N-methyl-N- (2,2-dimethoxyethyl) acetamide and N- (4,4-dimethoxybutyl) acetamide from the viewpoint of easy availability and synthesis of polymer compounds. It is preferably N- (2,2-dimethoxyethyl) acetamide.

[Weting agent]
The wetting agent of the present invention contains the above polymer compound and an aqueous medium. The wetting agent of the present invention includes water-soluble polymer compounds other than the above-mentioned polymer compounds, pH adjusters, preservatives, alcohols, chelating agents, as long as the function of the polymer compound as a wetting agent is not impaired. , Anionic surfactants, and at least one optional component selected from nonionic surfactants may be included.

The content of the polymer compound in the wetting agent of the present invention is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, still more preferably 0.008, from the viewpoint of improving wettability. It is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 3% by mass or less, still more preferably 1% by mass or less, from the viewpoint of economic efficiency. Yes, more preferably 0.5% by mass or less, and even more preferably 0.1% by mass or less.

Examples of the aqueous medium contained in the wetting agent of the present invention include water such as ion-exchanged water and ultrapure water, or a mixed medium of water and a solvent, and examples of the solvent include a solvent that can be mixed with water (for example,). , An alcohol such as ethanol) is preferable. As the aqueous medium, ion-exchanged water or ultrapure water is more preferable, and ultrapure water is even 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 not particularly limited, but from the viewpoint of economy, 95% by mass or more is preferable, and 98% by mass or more. Is more preferable, and substantially 100% by mass is further preferable.

The content of the aqueous medium in the wetting agent of the present invention is not particularly limited as long as the wetting agent can be handled well, and may be the residue of the polymer compound and any component.

[Polishing liquid composition for hydrophobic surface]
The polishing liquid composition of the present invention is a polishing liquid composition containing silica particles (component A), a nitrogen-containing basic compound (component B), the above polymer compound (component C), and an aqueous medium. Suitable for polishing the surface of silicon wafers.

[Silica particles (component A)]
The polishing liquid composition of the present invention contains silica particles as an abrasive. Specific examples of the silica particles include colloidal silica and fumed silica, but colloidal silica is more preferable from the viewpoint of improving the surface smoothness of the silicon wafer.

As the usage form of the silica particles, a slurry is preferable from the viewpoint of operability. When the abrasive contained in the polishing liquid composition of the present invention is colloidal silica, colloidal silica is obtained from a hydrolyzate of alkoxysilane from the viewpoint of preventing contamination of the silicon wafer by alkali metals, alkaline earth metals and the like. It is preferable that the material is silica. Silica particles obtained from a hydrolyzate of alkoxysilane can be produced by a conventionally known method.

The average primary particle size of the silica particles contained in the polishing liquid composition of the present invention is preferably 10 nm or more, more preferably 15 nm or more, further preferably 20 nm or more, and ensuring the polishing rate from the viewpoint of ensuring the polishing rate. From the viewpoint of achieving both reduction of surface roughness (haze) and reduction of surface defects (LPD) of the silicon wafer, 40 nm or less is preferable, 35 nm or less is more preferable, and 30 nm or less is further preferable.

In particular, when colloidal silica is used as the silica particles, the average primary particle size is preferably 10 nm or more, more preferably 15 nm or more, further preferably 20 nm or more, and the polishing speed. From the viewpoint of ensuring, reducing the surface roughness (haze) of the silicon wafer, and reducing the surface defects (LPD), 40 nm or less is preferable, 35 nm or less is more preferable, and 30 nm or less is further preferable.

The average primary particle size of the silica particles is calculated using the specific surface area S (m ² / g) calculated by the BET (nitrogen adsorption) method. The specific surface area can be measured, for example, by the method described in Examples.

The degree of association of the silica particles is preferably 3.0 or less, preferably 1.1 or more and 3.0 or less, from the viewpoint of ensuring the polishing rate and achieving both reduction of surface roughness (haze) and reduction of surface defects (LPD). Is more preferable, 1.8 or more and 2.5 or less is further preferable, and 2.0 or more and 2.3 or less is even more preferable. The shape of the silica particles is preferably so-called spherical and so-called eyebrows. When the silica particles are colloidal silica, the degree of association is 3.0 or less from the viewpoint of ensuring the polishing rate, reducing the surface roughness (haze) of the silicon wafer and reducing the surface defects (LPD). Preferably, 1.1 or more and 3.0 or less are more preferable, 1.8 or more and 2.5 or less are further preferable, and 2.0 or more and 2.3 or less are even more preferable.

The degree of association of silica particles is a coefficient representing the shape of silica particles, and is calculated by the following formula. The average secondary particle size is a value measured by a dynamic light scattering method, and can be measured using, for example, the apparatus described in the examples.
Association = average secondary particle size / average primary particle size

The method for adjusting the degree of association of silica particles is not particularly limited, and for example, JP-A-6-254383, JP-A-11-214338, JP-A-11-60232, JP-A-2005-060217, The method described in Japanese Patent Application Laid-Open No. 2005-060219 can be adopted.

The content of the silica particles contained in the polishing liquid composition of the present invention is preferably 0.01% by mass or more, more preferably 0.07% by mass or more, and 0, in terms of SiO ₂ , from the viewpoint of ensuring the polishing speed. .10% by mass or more is more preferable, and from the viewpoint of achieving both reduction of surface roughness (haze) and reduction of surface defects (LPD), 0.5% by mass or less is preferable in terms of SiO ₂ , and 0.3. It is more preferably mass% or less, and further preferably 0.2 mass% or less.

[Nitrogen-containing basic compound (component B)]
The polishing liquid composition of the present invention is water-soluble from the viewpoint of improving the storage stability of the polishing liquid composition, ensuring the polishing speed, reducing the surface roughness (haze) and reducing the surface defects (LPD). Contains basic compounds. The water-soluble basic compound is at least one kind of nitrogen-containing basic compound selected from ammonia, amine compounds and ammonium compounds. Here, "water-soluble" means having a solubility in water of 2 g / 100 ml or more, and "water-soluble basic compound" means a compound showing basicity when dissolved in water. ..

Examples of the nitrogen-containing basic compound include ammonia, ammonium hydroxide, ammonium carbonate, ammonium hydrogencarbonate, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, and N-1. Methylethanolamine, N-methyl-N, N monodietanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dibutylethanolamine, N- (β-aminoethyl) ethano- Luamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, ethylenediamine, hexamethylenediamine, piperazine / hexahydrate, piperazine anhydride, 1- (2-aminoethyl) piperazine, N-methylpiperazin, diethylenetriamine, and hydroxide. Tetramethylammonium can be mentioned. Two or more of these nitrogen-containing basic compounds may be mixed and used. As the nitrogen-containing basic compound that can be contained in the polishing liquid composition of the present invention, the storage stability of the polishing liquid composition is improved from the viewpoint of achieving both reduction of surface roughness (haze) and reduction of surface defects (LPD). , And ammonia is more preferable from the viewpoint of ensuring the polishing rate.

The content of the nitrogen-containing basic compound contained in the polishing liquid composition of the present invention is preferably 0.001% by mass or more from the viewpoint of achieving both reduction of surface roughness (haze) and reduction of surface defects (LPD). , 0.005% by mass or more is more preferable, 0.007% by mass or more is further preferable, 0.010% by mass or more is further preferable, 0.012% by mass or more is even more preferable, and from the same viewpoint, 0.1% by mass or less is preferable, 0.05% by mass or less is more preferable, 0.025% by mass or less is further preferable, 0.018% by mass or less is further preferable, and 0.014% by mass or less is further preferable. ..

[Polymer compound (component C)]
The content of the polymer compound (component C) contained in the polishing liquid composition of the present invention is 0.001% by mass or more from the viewpoint of achieving both reduction of surface roughness (haze) and reduction of surface defects (LPD). Is more preferable, 0.002% by mass or more is more preferable, 0.004% by mass or more is further preferable, 0.007% by mass or more is even more preferable, and from the same viewpoint, 0.1% by mass or less is preferable. It is more preferably 0.05% by mass or less, further preferably 0.035% by mass or less, and even more preferably 0.030% by mass or less.

[Aqueous medium]
As the aqueous medium contained in the polishing liquid composition of the present invention, the same aqueous medium contained in the wetting agent of the present invention can be used. The content of the aqueous medium in the polishing liquid composition of the present invention is not particularly limited, and may be the residue of components A to C and any component described later.

The pH of the polishing liquid composition of the present invention at 25 ° C. is preferably 8.0 or more, preferably 9.0 or more, from the viewpoint of improving the polishing rate, reducing the surface roughness (haze) and reducing the surface defects (LPD). The above is more preferable, 10.0 or more is further preferable, and 12.0 or less is preferable, and 11.5 or less is more preferable from the viewpoint of achieving both reduction of surface roughness (haze) and reduction of surface defects (LPD). It is preferable, and 11.0 or less is more preferable. The pH can be adjusted by appropriately adding a nitrogen-containing basic compound (component B) and / or a pH adjusting agent, if 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 1 minute after the electrode is immersed in the polishing liquid composition.

[Arbitrary ingredient (auxiliary agent)]
The polishing liquid composition of the present invention includes a water-soluble polymer compound (component D) other than the polymer compound (component C), a pH adjuster, a preservative, and an alcohol, as long as the effects of the present invention are not impaired. At least one optional component selected from the class, chelating agent, anionic surfactant, and nonionic surfactant may be contained.

[Water-soluble polymer compound (component D)]
From the viewpoint of reducing surface defects of the silicon wafer, the polishing liquid composition of the present invention may further contain a water-soluble polymer compound (component D) other than the polymer compound (component C). This water-soluble polymer compound (component D) is a polymer compound having a hydrophilic group, and the weight average molecular weight of the water-soluble polymer compound (component D) is such that the polishing rate is secured and the surface defects of the silicon wafer are reduced. From the viewpoint, 10,000 or more is preferable, and 100,000 or more is more preferable. Examples of the monomer as a supply source constituting the component E include a monomer having a water-soluble group such as an amide group, a hydroxyl group, a carboxyl group, a carboxylic acid ester group, and a sulfonic acid group. Examples of such a water-soluble polymer compound (component D) include polyamide, poly (N-acylalkyleneimine), cellulose derivative, polyvinyl alcohol, polyethylene oxide and the like. Examples of the polyamide include polyvinylpyrrolidone, polyacrylamide, polyoxazoline, polydimethylacrylamide, polydiethylacrylamide, polyisopropylacrylamide, polyhydroxyethylacrylamide and the like. Examples of poly (N-acylalkyleneimine) include poly (N-acetylethyleneimine), poly (N-propionylethyleneimine), poly (N-caproylethyleneimine), poly (N-benzoylethyleneimine), and poly (N-benzoylethyleneimine). N-nonadezoylethyleneimine), poly (N-acetylpropyleneimine), poly (N-butionylethyleneimine) and the like can be mentioned. Examples of the cellulose derivative include carboxymethyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl ethyl cellulose, and carboxymethyl ethyl cellulose. Two or more of these water-soluble polymer compounds may be mixed and used at an arbitrary ratio.

[pH regulator]
Examples of the pH adjuster include 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 benzalkonium chloride, benzethonium chloride, 1,2-benzisothiazolin-3-one, (5-chloro-) 2-methyl-4-isothiazolin-3-one, hydrogen peroxide, or hypochlorite. Examples thereof include acid salts.

[Alcohol]
Examples of alcohols include methanol, ethanol, propanol, butanol, isopropyl alcohol, 2-methyl-2-propanol, ethylene glycol, propylene glycol, polyethylene glycol, glycerin and the like. The content of alcohols in the polishing liquid composition of the present invention is preferably 0.1% by mass to 5% by mass.

[Chelating agent]
Chelating agents include ethylenediaminetetraacetic acid, sodium ethylenediaminetetraacetate, nitrilotriacetic acid, sodium nitrilotriacetate, ammonium nitrilotriacetate, hydroxyethylethylenediaminetriacetic acid, sodium hydroxyethylethylenediaminetriacetate, triethylenetetramine hexaacetic acid, triethylenetetramine. Examples include sodium hexaacetate. The content of the chelating agent in the polishing liquid composition of the present invention is preferably 0.01% by mass to 1% 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, and alkyl ether sulfates. Sulfate salts such as, and phosphoric acid ester salts such as alkyl phosphates can be mentioned.

[Nonionic surfactant]
Examples of 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, and poly. Examples thereof include polyethylene glycol type such as oxyalkylene (hardened) castor oil, polyhydric alcohol type such as sucrose fatty acid ester, polyglycerin alkyl ether, polyglycerin fatty acid ester and alkyl glycoside, and fatty acid alkanolamide.

The content of each component described above is the content at the time of use, but the polishing liquid composition of the present invention is stored and supplied in a concentrated state within a range in which the storage stability is not impaired. You may. In this case, it is preferable in that the manufacturing and transportation costs can be further reduced. The concentrated solution may be used by appropriately diluting it with the above-mentioned aqueous medium, if 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, 2 times or more is preferable, 10 times or more is more preferable, and 20 times or more is preferable. More than twice, more preferably 30 times or more, still more preferably 100 times or less, more preferably 80 times or less, even more preferably 60 times or less, even more preferably 50 times or less.

When the polishing liquid composition of the present invention is the concentrated liquid, the content of silica particles (component A) in the concentrated liquid is preferably 2% by mass or more in terms of SiO ₂ from the viewpoint of reducing production and transportation costs. 4, 4% by mass or more is more preferable, 6% by mass or more is further preferable, and from the viewpoint of improving storage stability, 40% by mass or less is preferable, 35% by mass or less is more preferable, and 20% by mass is obtained in terms of SiO _2. % Or less is even more preferable, 15% by mass or less is even more preferable, and 9% by mass or less is even more preferable.

When the polishing liquid composition of the present invention is the concentrated liquid, the content of the nitrogen-containing basic compound (component B) in the concentrated liquid is preferably 0.02% by mass or more from the viewpoint of reducing the production and transportation costs. , 0.05% by mass or more, more preferably 0.1% by mass or more, and from the viewpoint of improving storage stability, 5% by mass or less is preferable, 2% by mass or less is more preferable, and 1% by mass is used. The following is more preferable.

When the polishing liquid composition of the present invention is the concentrated liquid, the content of the polymer compound (component C) in the concentrated liquid is preferably 0.005% by mass or more, preferably 0, from the viewpoint of reducing the production and transportation costs. 0.01% by mass or more is more preferable, 0.02% by mass or more is further preferable, 0.05% by mass or more is further preferable, 0.1% by mass or more is even more preferable, and from the viewpoint of improving storage stability. Therefore, 5% by mass or less is preferable, 3% by mass or less is more preferable, 2% by mass or less is further preferable, and 1.5% by mass or less is even more preferable.

When the polishing liquid composition of the present invention is the concentrated liquid, the pH of the concentrated liquid at 25 ° C. is preferably 8.0 or more, more preferably 9.0 or more, still more preferably 9.5 or more, and 12.0 or less is preferable, 11.5 or less is more preferable, and 11.0 or less is further preferable.

Next, an example of the method for producing the polishing liquid composition of the present invention will be described.

An example of the method for producing the polishing liquid composition of the present invention is not limited in any way, and for example, silica particles (component A), a nitrogen-containing basic compound (component B), a polymer compound (component C), and an aqueous system are used. It can be prepared by mixing the medium with any component, if necessary.

Dispersion of silica particles in an aqueous medium can be performed using, for example, a stirrer such as a homomixer, a homogenizer, an ultrasonic disperser, a wet ball mill, or a bead mill. When coarse particles generated by aggregation of silica particles are contained in an aqueous medium, it is preferable to remove the coarse particles by centrifugation, filtration using a filter, or the like. The dispersion of the silica particles in the aqueous medium is preferably performed in the presence of the polymer compound (component C). Specifically, after preparing a wetting agent containing a polymer compound (component C) and an aqueous medium, the wetting agent and silica particles are mixed, and then, if necessary, a mixture of the wetting agent and silica particles. Is preferably diluted with an aqueous medium.

The polishing liquid composition of the present invention is used, for example, in a silicon wafer polishing method including a polishing step of polishing a silicon wafer and a polishing step of polishing a silicon wafer in a process of manufacturing a semiconductor substrate.

In the polishing step of polishing the silicon wafer, a wrapping (coarse polishing) step of flattening the silicon wafer obtained by slicing a silicon single crystal ingot into a thin disk shape and an etching of the wrapped silicon wafer. After that, there is a finish polishing step of mirroring the surface of the silicon wafer. The polishing liquid composition of the present invention is more preferably used in the above-mentioned finish polishing step.

The method for manufacturing a semiconductor substrate and the method for polishing a silicon wafer may include a diluting step for diluting the polishing liquid composition (concentrated liquid) of the present invention before the polishing step for polishing the silicon wafer. The aqueous medium may be used as the dilution medium.

The concentrate diluted in the dilution step contains, for example, 2 to 40% by mass of component A, 0.02 to 5% by mass of component B, and 0.02 to 5% by mass of component C from the viewpoints of reducing manufacturing and transportation costs and improving storage stability. Is preferably contained in an amount of 0.005 to 5% by mass.

The methods for synthesizing the polymer compounds a to i in Table 1 used in Examples 1 to 4 and Comparative Examples 1 to 5 below are as follows.

(1) Method for synthesizing polymer compounds, etc. (1-1) Synthesis of N- (2,2-dimethoxyethyl) acetamide N- (2,2-dimethoxy) used for the synthesis of the amide-modified polyvinyl acetal shown in Table 1. The synthesis of ethyl) acetamide was carried out as follows.
In a nitrogen-substituted reactor, acetic anhydride (18.3 g) and triethylamine (18.2 g) were added to 2,2-dimethoxyethylamine (15.7 g) dissolved in tetrahydrofuran (250 g), and the mixture was stirred at room temperature for 2 hours. went. After completion of the reaction, the mixture was partially volatilized by evaporation and then neutralized with saturated aqueous sodium hydrogen carbonate solution. Then, it was separated into an oil layer and an aqueous layer, and the oil content was extracted from the aqueous layer with dichloromethane three times. Subsequently, the oil content obtained by extraction and the oil layer were mixed, and the oil layer was washed with saturated brine. Then, after removing water with anhydrous sodium sulfate, 18.0 g of oily N- (2,2-dimethoxyethyl) acetamide was obtained by filtration and drying.

(1-2) Synthesis of Polymer Compound a 10.0 g of Kuraray Poval PVA-117 (saponification degree 98-99%, weight average molecular weight 70,000) was dissolved in 90.0 g of hot water and then cooled to room temperature. To the obtained PVA solution, 3.68 g of N- (2,2-dimethoxyethyl) acetamide and 10.0 g of concentrated hydrochloric acid were added, and the mixture was stirred at room temperature for 24 hours. Subsequently, it was neutralized to pH 7 with a 5 mass% sodium hydroxide aqueous solution. The obtained reaction solution was ultrafiltered through a dialysis membrane (Spectrapore 7 RC dialysis tube fractional molecular weight 1,000, manufactured by Spectrum Laboratories Inc.). The filtered reaction solution was freeze-dried to obtain 10.3 g of a white solid (amide-modified polyvinyl acetal, weight average molecular weight 70,000, acetalization rate 11%). By 1H-NMR, it was confirmed that 11 mol% of OH groups were denatured into acetal groups. In the general formula (2), Z1 is −Y ¹ NR ¹ R ² , Y ¹ is a methylene group, and R ¹ and R ² are both methyl groups.

(1-3) Synthesis of polymer compound b
White solid (amide-modified polyvinyl acetal, weight average molecular weight 70,000, acetalization) by the same method as the method for synthesizing the polymer compound a except that the amount of N- (2,2-dimethoxyethyl) acetamide added was 4.68 g. Rate 17%) 10.7 g was obtained. By 1H-NMR, it was confirmed that 17 mol% of OH groups were denatured into acetal groups.

(1-4) Synthesis of polymer compound c
White solid (amide-modified polyvinyl acetal, weight average molecular weight 70,000, acetal) by the same method as the method for synthesizing the polymer compound a except that the amount of N- (2,2-dimethoxyethyl) acetamide added was 6.69 g. Conversion rate 23%) 12.0 g was obtained. By 1H-NMR, it was confirmed that 23 mol% of OH groups were denatured into acetal groups.

(1-5) Synthesis of polymer compound d Polymer compound b, except that Clarepovar PVA-105 (saponification degree 98-99%, weight average molecular weight 20,000) was used instead of Clarepovar PVA-117. 10.5 g of a white solid (amide-modified polyvinyl acetal, weight average molecular weight 20,000, acetalization rate 17%) was obtained by the same method as the synthesis method of. By 1H-NMR, it was confirmed that 17 mol% of OH groups were denatured into acetal groups.

(1-6) Polymer compound e
As the polymer compound e, Kuraray Povar PVA-105 (PVA, saponification degree 98-99%, weight average molecular weight 20,000, acetalization rate 0%) was used.

(1-7) Polymer compound f
20.0 g of poly (1-vinylpyrrolidone-co-vinyl acetate) (Sigma-Aldrich # 190845) was dissolved in 180 g of methanol, 2.00 g of NaOH was further added, and stirring was maintained at 40 ° C. for 6 hours. The obtained reaction solution was dried to remove methanol, and then ultrafiltered with a dialysis membrane (Spectrapore 7 RC dialysis tube fractional molecular weight 1,000, manufactured by Spectrum Laboratories Inc.). The filtered reaction solution was freeze-dried to obtain 15.2 g of a white solid (PVA-co-PVA, weight average molecular weight of 50,000).

(1-8) Polymer compound g
As the polymer compound g, ethylene oxide-added polyvinyl alcohol (EO-modified PVA, trade name: Ekomati 320R, weight average molecular weight 70,000, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was used.

(1-9) Polymer compound h
An alkyl-modified polyvinyl acetal was synthesized by the method described in Production Example 2 of JP-A-2015-076494 (Japanese Patent Application No. 2013-211489) to obtain a polymer compound h. By 1H-NMR, it was found that 28 mol% of the OH groups were changed to acetal groups having alkyl groups. The weight average molecular weight was 30,000.

(1-10) Polymer compound i
A PVA-PVP graft copolymer was synthesized according to JP-A-2009-147267. Kuraray Povar PVA-105 (PVA, saponification degree 98-99%, weight average molecular weight 20,000) was used for PVA, and 43 wt% (vs. PVA) of N-vinyl-2-pyrrolidone was used. As a result, a PVA-PVP graft copolymer (weight average molecular weight of 50,000) was obtained as the polymer compound i.

(2) Measurement method of various parameters (2-1) Measurement of weight average molecular weight of polymer compound The weight average molecular weight of the polymer compound shown in Table 1 is determined by gel permeation chromatography (GPC) method under the following conditions. Calculated based on the peaks in the chromatogram obtained by application. The weight average molecular weight of the polymer compound e is a catalog value.
<Measurement condition>
Equipment: HLC-8320 GPC (Tosoh Corporation, integrated detector)
Column: GMPWXL + GMPWXL (anion)
Eluent: 0.2M phosphate buffer / CH ₃ CN = 9/1
Flow rate: 0.5 ml / min
Column temperature: 40 ° C
Detector: RI Detector Standard Material: Polyethylene Glycol

(2-2) Average primary particle diameter of silica particles The average primary particle diameter (nm) of silica particles is calculated by the following formula using the specific surface area S (m ² / g) calculated by the BET (nitrogen adsorption) method. did.
Average primary particle size (nm) = 2727 / S

For the specific surface area of the silica particles, after performing the following [pretreatment], about 0.1 g of the measurement sample is concentrated in the measurement cell to 4 digits after the decimal point, and immediately before the measurement of the specific surface area, 30 minutes in an atmosphere of 110 ° C. After drying, it was measured by the nitrogen adsorption method (BET method) using a specific surface area measuring device (micromeritic automatic specific surface area measuring device Flowsorb III2305, manufactured by Shimadzu Corporation).

[Preprocessing]
(A) The slurry-like silica particles are adjusted to pH 2.5 ± 0.1 with an aqueous nitric acid solution.
(B) The slurry-like silica particles adjusted to pH 2.5 ± 0.1 are taken 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 crushed in an agate mortar.
(D) The pulverized sample is 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) Take the filter to which the filter material is attached in a petri dish and dry it in an atmosphere of 110 ° C. for 4 hours.
(G) A dried filter (abrasive grains) was taken so as not to be mixed with filter debris, and finely pulverized in a mortar to obtain a measurement sample.

(2-3) Average Secondary Particle Diameter of Silica Particles The average secondary particle diameter (nm) of silica particles is obtained after adding silica particles to ion-exchanged water so that the concentration of silica particles is 0.25% by mass. , The obtained aqueous solution was put into a Disposable Particle Cuvette (10 mm cell made of polystyrene) up to a height of 10 mm from the bottom, and measured using a dynamic light scattering method (device name: Zetasizer Nano ZS, manufactured by Sysmex Co., Ltd.). did.

(3) Preparation of polishing liquid composition Silica particles (colloidal silica, average primary particle diameter 35 nm, average secondary particle diameter 70 nm, degree of association 2), polymer compound, 28% by mass ammonia water (Kishida Chemical Co., Ltd. reagent special grade) ), Ion-exchanged water was stirred and mixed to obtain polishing solution compositions of Examples 1 to 4 and Comparative Examples 1 to 5 (concentrated solution, pH 10.6 ± 0.1 (25 ° C.)). Each evaluation in Table 1 is a value using the polishing liquid composition obtained by diluting the polishing liquid composition 40 times with ion-exchanged water. The content of silica particles, polymer compound, and ammonia in the polishing liquid composition (pH 10.6 ± 0.1 (25 ° C.)) obtained by diluting the concentrated liquid 40 times is 0.17% by mass (SiO ₂ equivalent), respectively. Concentration), 0.01% by mass, and 0.01% by mass.

(4) Various evaluation methods (4-1) Polishing method The polishing liquid composition obtained by diluting the concentrated liquid 40 times is filtered with a filter (compact cartridge filter MCP-LX-C10S Advantech Co., Ltd.) immediately before polishing. Finish polishing was performed on the following silicon wafers (silicon single-sided mirror wafers with a diameter of 200 mm (conduction type: P, crystal orientation: 100, resistance 0.1Ω ・ cm or more and less than 100Ω ・ cm) under the following polishing conditions. Prior to the finish polishing, the silicon wafer was roughly polished using a commercially available polishing agent composition. The surface roughness (haze) of the silicon wafer after the rough polishing was completed and subjected to the finish polishing was 2.775. It was (ppm). The surface roughness (haze) is a value in the dark field wide oblique incident channel (DWO) measured using Surfscan SP1 (trade name) manufactured by KLA Tencor.

<Finishing conditions>
Polishing machine: Single-sided 8-inch polishing machine GRIND-X SPP600s (manufactured by Okamoto)
Polishing pad: Suede pad (Toray Coatex Asker Hardness 64 Thickness 1.37mm Knap length 450um Opening diameter 60um)
Silicon wafer polishing pressure: 100 g / cm ²
Surface plate rotation speed: 60 rpm
Polishing time: 5 minutes Supply rate of abrasive composition: 150 ml / cm ²
Abrasive composition temperature: 23 ° C
Carrier rotation speed: 60 rpm

After finish polishing, 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 a flow rate of 1 L / min at 600 rpm for 3 minutes. At this time, the temperature of 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% ammonium hydrogen fluoride (special grade: Nacalai Tesque, Inc.) was sprayed from a nozzle toward the center of a silicon wafer rotating at a flow rate of 1 L / min at 600 rpm for 6 seconds. A total of two sets were performed with the above ozone cleaning and dilute hydrofluoric acid cleaning as one set, and finally spin drying was performed. In spin drying, the silicon wafer was rotated at 1500 rpm.

(4-2) Polishing speed 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 measured as the density, area and polishing time of the silicon wafer. Divided by, the single-sided polishing rate per unit time was determined.

(4-3) Evaluation of Surface Roughness (Haze) and Surface Defects (LPD) of Silicon Wafer For evaluation of surface roughness (haze) of silicon wafer surface after cleaning, the surface roughness measuring device "Surfscan SP1-DLS" The value at the dark field wide oblique incident channel (DWO) measured using (KLA Tencor) was used. Further, the surface defect (LPD) was measured at the same time as the Haze measurement, and was evaluated by measuring the number of particles having a particle size of 45 nm or more on the surface of the silicon wafer. The evaluation result of the surface defect (LPD) shows that the smaller the value, the smaller the surface defect. Further, the smaller the value of Haze, the higher the flatness of the surface. The results of polishing rate, surface defects (LPD) and surface roughness (haze) are shown in Table 1. The polishing speed, surface roughness (haze) and surface defect (LPD) were measured on two silicon wafers, and the average values were shown for each.

As shown in Table 1, by using the polishing liquid compositions of Examples 1 to 4, the polishing speed is improved and the surface roughness is improved as compared with the case where the polishing liquid compositions of Comparative Examples 1 to 5 are used. It has become possible to achieve both reduction of (haze) and surface defects (LPD).

By using the wetting agent of the present invention, it is possible to satisfactorily wet a hydrophobic surface such as a silicon wafer surface, a siliconized silicon film surface, and a polysilicon film surface. Further, if the wetting agent of the present invention is used for polishing a hydrophobic surface, it is possible to improve the polishing speed and reduce the surface roughness (haze) and the surface defect (LPD) at the same time. Therefore, the polishing liquid composition of the present invention is useful in various steps of manufacturing a semiconductor, and in particular, is useful as a polishing liquid composition for finish polishing of a silicon wafer.

Claims (10)

A polymer compound containing a structural unit I represented by the following general formula (1), a structural unit II represented by the following general formula (2), and a structural unit III represented by the following general formula (3). Wetting agent contained.
However, in the above general formula (2), Z ¹ represents a substituent containing one or more of a nitrogen atom and an oxygen atom.
However, in the above general formula (3), X ¹ represents a nitrogen atom or an oxygen atom, and n represents a number of 1 or more and 5 or less. In the general formula (2), Z ^{1 is, -Y 1 NR 1 R 2,} -Y 1 NHCOR 3, -Y 1 CONHR 4 or - (AO) m-H, Y 1 is 1 or more carbon atoms It is an alkylene group of 4 or less, R ¹ , R ² , R ³ and R ⁴ are independently hydrogen atoms or alkyl groups having 1 or more and 4 or less carbon atoms, and AO is an oxyalkylene group having 2 or more and 4 or less carbon atoms. The wetting agent according to claim 1, wherein m is an average number of added moles of AO, which is a number representing 1 or more and 100 or less. The wetting agent according to claim 1 or 2 , wherein the polymer compound contains 1 mol% or more of the structural unit II. The wetting agent according to any one of claims 1 to 3 , wherein the polymer compound has a weight average molecular weight of 1,000 or more and 500,000 or less. Silica particles (component A) and
At least one nitrogen-containing basic compound (component B) selected from ammonia, amine compounds and ammonium compounds, and
A polishing liquid for a hydrophobic surface containing a polymer compound (component C) containing a structural unit I represented by the following general formula (1) and a structural unit II represented by the following general formula (2). Composition.
However, in the above general formula (2), Z ¹ represents a substituent containing one or more of a nitrogen atom and an oxygen atom. In the general formula (2), Z ^{1 is, -Y 1 NR 1 R 2,} -Y 1 NHCOR 3, -Y 1 CONHR 4 or - (AO) m-H, Y 1 is 1 or more carbon atoms It is an alkylene group of 4 or less, R ¹ , R ² , R ³ and R ⁴ are independently hydrogen atoms or alkyl groups having 1 or more and 4 or less carbon atoms, and AO is an oxyalkylene group having 2 or more and 4 or less carbon atoms. , M is the average number of added moles of AO, which is a number representing 1 or more and 100 or less. The polishing liquid composition for a hydrophobic surface according to claim 5 . The polishing solution composition for a hydrophobic surface according to claim 5 or 6 , wherein the pH at 25 ° C. is 8.0 or more and 12.0 or less. The hydrophobic surface polishing liquid composition according to any one of claims 5 to 7 , wherein the hydrophobic surface polishing liquid composition is a silicon wafer polishing liquid composition for polishing a silicon single crystal. A method for polishing a silicon wafer, which comprises a step of polishing the silicon wafer using the polishing liquid composition for a hydrophobic surface according to any one of claims 5 to 8 . A method for manufacturing a semiconductor substrate, which comprises a step of polishing a silicon wafer using the polishing liquid composition for a hydrophobic surface according to any one of claims 5 to 8 .