Polishing composition, polishing method, and method for producing polished substrate

Abstract

According to the present invention, in grinding using the grinding composition, a moderately high grinding speed can be achieved for a specific material, and an appropriate grinding speed ratio can be achieved between two or more different materials. The present invention relates to a grinding composition comprising abrasive particles, a water-soluble polymer without alcoholic hydroxyl groups in its side chains, a polycarboxylic acid (salt), and an oxidizing agent, and having a pH less than 6.

Description

[Technical Field]

[0001] This invention relates to a polishing composition, a polishing method, and a method for manufacturing a polished substrate. [Previous Technology]

[0002] In the semiconductor industry, planarization techniques are generally used to improve the flatness of the surface of semiconductor substrates (e.g., wafers). Chemical mechanical polishing (CMP) is one of the commonly known planarization techniques. CMP is a technique that uses a polishing composition containing, for example, abrasive particles such as silica, alumina, or cerium oxide, as well as etching inhibitors and surfactants, to planarize the surface of a workpiece (such as a semiconductor substrate).

[0003] In recent years, silicon substrates containing germanium materials (also referred to as "germanium-containing substrates" in this specification) have become increasingly popular as semiconductor substrates. As a result, the demand for polishing compositions suitable for polishing germanium-containing substrates has also been increasing.

[0004] Japanese Patent Application Publication No. 2014-527298 (corresponding to U.S. Patent Application Publication No. 2014 / 0199841) discloses a chemical mechanical polishing composition comprising (A) inorganic particles, organic particles, or mixtures or complexes thereof, (B) at least one oxidant, and (C) an aqueous medium. Furthermore, the chemical mechanical polishing composition of this document discloses its application to the chemical mechanical polishing of materials made of germanium or silicon-germanium. [Summary of the Invention]

[0005] In the chemical mechanical polishing process, it is necessary to increase the high polishing speed for specific materials. Furthermore, when polishing an object containing two or more different materials, a step difference may sometimes occur on the surface of the object, and it is necessary to reduce this step difference. Moreover, when polishing an object containing two or more different materials, a phenomenon called dish-shaped depression may sometimes occur, that is, one material is excessively ground below the surface of another material, and it is necessary to reduce this dish-shaped depression.

[0006] However, for the chemical mechanical polishing composition of Japanese Patent Application Publication No. 2014-527298 (corresponding to U.S. Patent Application Publication No. 2014 / 0199841), there are the following problems: it is difficult to achieve a high polishing speed for a specific material, and it is difficult to reduce the step difference and the disc-shaped depression when polishing a polishing object containing two or more different materials.

[0007] Therefore, as a result of the research, the inventors found that the step difference and the disc-shaped depression are related to the grinding speed of each material.

[0008] The present invention was made in view of the above-mentioned problems, and its object is to provide a technical means that, in the grinding process using a grinding composition, can achieve a moderately high grinding speed for a specific material and can achieve a grinding speed ratio within an appropriate range between two or more different materials.

[0009] As an example of solving the above-mentioned problems of the present invention, the following means can be cited.

[0010] A grinding composition comprising abrasive particles, a water-soluble polymer without alcoholic hydroxyl groups in its side chain, a polycarboxylic acid (salt) and an oxidizing agent, and having a pH less than 6.

Implementation Method

[0012] [Form for implementing the invention]

[0013] Embodiments of the present invention will be described below. However, the present invention is not limited to the following embodiments.

[0014] In this specification, the range "X~Y" means "above X and below Y". Unless otherwise specified, the operation and physical properties are measured at room temperature (above 20°C and below 25°C) and relative humidity of 40% RH and below 50% RH.

[0015] <Grinding Composition> One aspect of the present invention relates to a grinding composition comprising abrasive particles, a water-soluble polymer without alcoholic hydroxyl groups in its side chains, a polycarboxylic acid (salt), and an oxidizing agent, and having a pH less than 6. According to the present invention, a technical means is provided that, in grinding using the grinding composition, can achieve a moderately high grinding speed for a specific material and can achieve an appropriate grinding speed ratio between two or more different materials.

[0016] The inventors speculate that the mechanism capable of solving the above-mentioned problems is as follows. In one aspect of the grinding composition of the present invention, the oxidant acts on a specific material in the object to be ground, thereby making the grinding of the specific material easier. In this way, the oxidant helps to increase the grinding speed of the specific material (e.g., germanium-containing materials, polycrystalline silicon, etc.). Furthermore, polycarboxylic acids (salts) help to increase the grinding speed of the specific material (e.g., germanium-containing materials, polycrystalline silicon, etc.). The reason for this is not yet clear, but it is believed to be due to the conductivity of the grinding composition, the characteristics of the molecular structure of the polycarboxylic acid (salt), etc. Then, a water-soluble polymer without alcoholic hydroxyl groups in its side chain adsorbs onto the surface of the specific material in the object to be ground, reducing the hydrophilicity of the specific material and increasing the repulsive force between the grinding composition and the specific material. Therefore, a water-soluble polymer without alcoholic hydroxyl groups in its side chain helps to reduce the grinding speed of the specific material (e.g., germanium-containing materials, polycrystalline silicon, etc.). Furthermore, the pH of the grinding composition of the present invention is less than 6, thereby preventing the grinding speed of certain materials (e.g., germanium-containing materials, polycrystalline silicon, etc.) from becoming too high, and preventing the grinding speed of other specific materials (e.g., silicon oxide, etc.) from becoming too low. As a result, in grinding using the grinding composition of the present invention, the grinding speed of specific materials (e.g., germanium-containing materials, etc.) is moderately high but not excessively high, thus remaining within an excellent range. Furthermore, a suitable range of grinding speed ratios can be achieved between two or more different materials (e.g., between germanium-containing materials and polycrystalline silicon, between germanium-containing materials and silicon oxide, etc.). Therefore, high grinding efficiency can be achieved, and the reduction of step and disc-shaped depressions is well realized. Also, the above mechanism is based on conjecture, and its correctness does not affect the technical scope of the present invention.

[0017] Hereinafter, we will provide a detailed description of each component contained in the grinding composition, the object to be ground, etc.

[0018] [Abrasive particles] One embodiment of the grinding composition of the present invention includes abrasive particles. The abrasive particles increase the grinding speed by mechanically grinding the object to be ground.

[0019] There are no particular limitations on the abrasive particles; they can be any type of inorganic or organic particle. As inorganic particles, there are no particular limitations; examples include particles formed from metal oxides such as silicon oxide, aluminum oxide, cerium oxide, and titanium oxide. As organic particles, there are no particular limitations; examples include polymethyl methacrylate (PMMA) particles. Among these, silicon oxide (silicon oxide abrasive particles) is preferred as abrasive particles, and colloidal silicon oxide (colloidal silicon oxide abrasive particles) is even more preferred.

[0020] The abrasive grains can be surface-modified. Since the interfacial (zeta) potential of abrasive grains such as silicon oxide is close to zero under acidic conditions, the grains do not electrostatically repel each other and tend to aggregate. In contrast, surface-modified abrasive grains have a relatively large positive or negative interfacial potential even under acidic conditions, and therefore disperse well even under acidic conditions due to strong mutual repulsion. This improves the storage stability of the grinding composition. Therefore, it is possible to achieve a better range for the grinding speed of a specific material (e.g., germanium-containing materials) and the ratio of grinding speeds between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials). Surface-modified abrasive grains can be obtained by mixing, for example, coupling agents containing metals such as aluminum, titanium, or zirconium in their molecular structure, or coupling agents containing functional groups such as carboxylic acid groups, sulfonic acid groups, phosphonic acid groups, or amino groups, with abrasive grains, allowing them to be physically adsorbed or chemically bonded to the surface of the abrasive grains. Furthermore, since the interfacial potential of abrasive grains such as silicon oxide is negative under alkaline conditions, regardless of surface modification, they are generally well dispersed. However, compared to unmodified abrasive grains, surface-modified abrasive grains have a larger absolute value of interfacial potential, thus achieving more stable dispersion.

[0021] There are no particular limitations on the surface-modified abrasive grains, but abrasive grains with covalently bonded organic acid functional groups (also referred to as "organic acid immobilization" in this specification) on their surface are preferred. Furthermore, silicon oxide with organic acid immobilized on its surface (silicon oxide abrasive grains with organic acid immobilized on its surface) is preferred, and colloidal silicon oxide with organic acid immobilized on its surface (colloidal silicon oxide abrasive grains with organic acid immobilized on its surface) is even more preferred. The organic acid functional groups can be in an acidic state or a salt state. Based on these abrasive grains, the ratio of the grinding speed of a specific material (e.g., germanium-containing materials) and the grinding speed between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials) can be made into a better range. The immobilization of organic acid on the colloidal silicon oxide surface is carried out by chemically bonding the functional groups of the organic acid to the surface of the colloidal silicon oxide. Simply allowing colloidal silica to coexist with organic acids is insufficient to immobilize the organic acids on the surface of the colloidal silica. To immobilize sulfonic acids, one type of organic acid, on colloidal silica, a method described, for example, in the literature "Sulfonic acid-functionalized silica through quantitative oxidation of thiol groups", Chem. Commun. 246-247 (2003), can be used. Specifically, by coupling colloidal silica with a silane coupling agent containing thiol groups, such as 3-mercaptopropyltrimethoxysilane, and then oxidizing the thiol groups with hydrogen peroxide, colloidal silica with sulfonic acids immobilized on its surface can be obtained. The colloidal silica used in the embodiments of this application was also manufactured using this method. Alternatively, if one wishes to immobilize carboxylic acids on the surface of colloidal silica, this can be achieved, for example, by the method described in the literature "Novel Silane Coupling Agents Containing a Photolabile 2-Nitrobenzyl Ester for Introduction of a Carboxy Group on the Surface of Silica Gel", Chemistry Latters, 3, 228-229 (2000). Specifically, after coupling a silane coupling agent containing photoreactive 2-nitrobenzyl ester with colloidal silica, light irradiation is performed, thereby obtaining colloidal silica with carboxylic acid groups immobilized on its surface.

[0022] The shape of the abrasive particles is not particularly limited; they can be spherical or non-spherical. Specific examples of non-spherical particles include polygonal prisms such as triangular prisms and quadrangular prisms, cylindrical shapes, straw-bag shapes with a central protrusion from the end of a cylinder, donut shapes with a centrally connected disc, plate-like shapes, so-called cocoon shapes with a central constriction, so-called associated spheres with multiple particles integrated, bead-like shapes with multiple particles connected in a roughly row, so-called konpeito shapes with multiple protrusions on the surface, rugby ball shapes, needle-like shapes that are thinner than rugby balls, etc. There are no particular limitations. Among these, cocoon shapes are preferred. By making the abrasive particles cocoon-shaped, the ratio of the grinding speed of a specific material (e.g., germanium-containing materials) and the grinding speed between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials) can be within a better range.

[0023] The average primary particle size of the abrasive grains is not particularly limited, but preferably 5 nm or more, more preferably 7 nm or more, further preferably 10 nm or more, even more preferably 25 nm or more, and especially preferably 30 nm or more. If it falls within such a range, the grinding speed will be increased. Furthermore, the average primary particle size of the abrasive grains is not particularly limited, but preferably 120 nm or less, more preferably 80 nm or less, further preferably 50 nm or less, and especially preferably 40 nm or less. If it falls within such a range, the ratio of the grinding speed of a specific material (e.g., germanium-containing materials) and the grinding speed between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials) can be within a better range. Also, the specific surface area of ​​the abrasive grains can be measured using the BET method, and based on the measured specific surface area, the value of the average primary particle size of the abrasive grains can be calculated.

[0024] The average secondary particle size of the abrasive particles is not particularly limited, but is preferably 10 nm or more, more preferably 20 nm or more, further preferably 30 nm or more, and especially preferably 50 nm or more. If it falls within such a range, the grinding speed will be increased. Furthermore, the average secondary particle size of the abrasive particles is not particularly limited, but is preferably 250 nm or less, more preferably 200 nm or less, further preferably 150 nm or less, and especially preferably 100 nm or less. If it falls within such a range, the ratio of the grinding speed of a specific material (e.g., germanium-containing materials) and the grinding speed between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials) can be within a better range. The average secondary particle size of the abrasive particles can be determined using a dynamic light scattering method.

[0025] Abrasive particles can be commercially available or synthetic.

[0026] Abrasive particles can be used alone or in combination of two or more.

[0027] The concentration of abrasive particles in the grinding composition is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, further preferably 0.1% by mass or more, and especially preferably 0.5% by mass or more, relative to the total mass of the grinding composition. Within such a range, the grinding speed will be increased. Furthermore, the ratio of grinding speeds between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials, etc.) can be within a better range. The concentration of abrasive particles in the grinding composition is not particularly limited, but is preferably 20% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, and especially preferably 3% by mass or less, relative to the total mass of the grinding composition. Within such a range, the grinding speed of a specific material (e.g., germanium-containing materials, etc.) and the ratio of grinding speeds between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials, etc.) can be within a better range.

[0028] [Water-soluble polymer without alcoholic hydroxyl groups in the side chain] A grinding composition according to an embodiment of the present invention comprises a water-soluble polymer without alcoholic hydroxyl groups in the side chain. The water-soluble polymer without alcoholic hydroxyl groups in the side chain can reduce the grinding speed of a specific material.

[0029] As a water-soluble polymer that does not have alcoholic hydroxyl groups in its side chain, there are no particular restrictions as long as it has such a structure, but it is preferable that the structure contains a polyalkylene oxide group represented by the following formula (I).

[0030] [Chemical Formula 1]

[0031] In the above formula (I), X is an integer greater than 2, and n is an integer greater than 2.

[0032] The CxH2x part in the above formula (I) represents the alkyl group. The alkyl group can be a straight-chain alkyl group or a branched alkyl group. Furthermore, a water-soluble polymer containing the polyolefin oxygen group represented by the above formula (I) can contain structural units having a straight-chain alkyl group and structural units having a branched alkyl group.

[0033] In the above formula (I), there is no particular restriction as long as X is an integer of 2 or above, but it is preferably an integer of 3 or above. Furthermore, there is no particular restriction on X, but it is preferably an integer of 12 or below, more preferably an integer of 6 or below, even more preferably an integer of 5 or below, and especially preferably an integer of 4 or below. Among them, X of 3 is especially preferred.

[0034] In the above formula (I), n represents the number of repeating units (number of structural units). There are no particular restrictions on n as long as it is an integer of 2 or higher, but it is preferably an integer of 4 or higher, more preferably an integer of 5 or higher, even more preferably an integer of 6 or higher, and most preferably an integer of 12 or higher. Furthermore, there are no particular restrictions on n, but it is preferably an integer less than 150, more preferably an integer less than 100, even more preferably an integer less than 50, and most preferably an integer less than 20.

[0035] By using the compound of the above formula (I), it is possible to make the ratio of the grinding speed of a specific material (e.g., germanium-containing material) and the grinding speed between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials) into a better range.

[0036] Furthermore, as a water-soluble polymer that does not have alcoholic hydroxyl groups in its side chain, it is preferable to have a water-soluble polymer that does not have a lactam structure and does not have alcoholic hydroxyl groups in its side chain.

[0037] There are no particular limitations on the water-soluble polymer that does not have alcoholic hydroxyl groups in its side chain; examples include, for instance, polyalkylene glycol. There are no particular limitations on the polyalkylene glycol; examples include, for instance, polyethylene glycol, polypropylene glycol, polybutane glycol, polypentane glycol, polyhexane glycol, polyheptane glycol, polyoctane glycol, polynonane glycol, and polydecane glycol. Preferably, the water-soluble polymer that does not have alcoholic hydroxyl groups in its side chain is selected from at least one group consisting of polyethylene glycol, polypropylene glycol, polybutane glycol, polypentane glycol, polyhexane glycol, polyheptane glycol, polyoctane glycol, polynonane glycol, and polydecane glycol. Polypropylene glycol is particularly preferred.

[0038] Furthermore, here, for example, polypropylene glycol is a general term for "polytrimethylene ether glycol", "polymethyl ethyl ether glycol", "polydimethyl methyl ether glycol", etc. Similarly, for the polyalkylene glycols below polybutane glycol mentioned above, it is also a general term for polyalkylene glycols having a straight-chain structure and polyalkylene glycols having various branched structures.

[0039] By using these compounds, the ratio of the grinding speed of a specific material (e.g., germanium-containing material) and the grinding speed between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials) can be made into a better range.

[0040] The weight-average molecular weight of the water-soluble polymer that does not have alcoholic hydroxyl groups in its side chain is not particularly limited, but is preferably 200 or more, more preferably 300 or more. If it is within such a range, the ratio of grinding speeds between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials, etc.) can be within a more favorable range. Furthermore, the weight-average molecular weight of the water-soluble polymer that does not have alcoholic hydroxyl groups in its side chain is not particularly limited, but is preferably 3,000 or less, more preferably less than 1,000, and even more preferably 800 or less. If it is within such a range, the ratio of grinding speed of a specific material (e.g., germanium-containing materials, etc.) to the grinding speeds between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials, etc.) can be within a more favorable range.

[0041] The weight-average molecular weight of a water-soluble polymer that does not have alcoholic hydroxyl groups in its side chain can be determined by gel permeation chromatography (GPC) using polyethylene oxide (manufactured by Sigma-Aldrich) as a standard material under the following conditions.

[0042] Apparatus: Manufactured by Tosoh Corporation; Model: HLC-8320GPC; Column: KF-802.5 (Shodex (registered trademark), Showa Denko Corporation); Effluent: THF (tetrahydrofuran); Flow rate: 1 mL / min; Detector: LS laser light scattering detector, Shodex RI detector; Oven temperature: 30℃; Injection volume: 100 μl.

[0043] Water-soluble polymers that do not have alcoholic hydroxyl groups in their side chains can be commercially available or synthetic products.

[0044] Water-soluble polymers that do not have alcoholic hydroxyl groups in their side chains can be used alone or in combination of two or more.

[0045] The concentration of the water-soluble polymer without alcoholic hydroxyl groups in the side chain of the grinding composition (the mass (g) of the water-soluble polymer without alcoholic hydroxyl groups in the side chain of 1L of the grinding composition) is not particularly limited, but preferably 0.01 g / L or more, more preferably 0.1 g / L or more, further preferably 0.5 g / L or more, particularly preferably 1 g / L or more, and most preferably 2 g / L or more. If it is within such a range, the grinding speed of a particular material (e.g., germanium-containing materials, etc.) will be further reduced. Furthermore, the ratio of grinding speeds between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials, etc.) can be within a better range. Furthermore, the concentration of the water-soluble polymer without alcoholic hydroxyl groups in the side chain of the grinding composition (the mass (g) of the water-soluble polymer without alcoholic hydroxyl groups in the side chain of 1L of the grinding composition) is not particularly limited, but is preferably 20 g / L or less, more preferably 10 g / L or less, further preferably 5 g / L or less, and especially preferably 2.5 g / L or less. Within such a range, the grinding speed of a specific material (e.g., a germanium-containing material) and the ratio of grinding speeds between two or more different materials (e.g., between a germanium-containing material and a silicon-containing compound other than a germanium-containing material) can be within a more favorable range.

[0046] [Water-soluble polymer having alcoholic hydroxyl groups in the side chain] The grinding composition of one embodiment of the present invention may further include a water-soluble polymer having alcoholic hydroxyl groups in the side chain. The water-soluble polymer having alcoholic hydroxyl groups in the side chain can reduce the grinding speed of a particular material. By this effect, it is expected that the reduction effect of step and disc-shaped depression when grinding objects containing two or more different materials can be further improved.

[0047] As a water-soluble polymer having an alcoholic hydroxyl group in the side chain, there are no particular restrictions as long as it has such a structure, and it is preferable to include compounds in the structure that contain a vinyl alcohol unit (a structural part represented by -CH2-CH(OH)-; hereinafter also referred to as "VA unit").

[0048] A compound containing VA units in its structure may be one in which all repeating units are substantially composed of VA units. Furthermore, a compound containing VA units in its structure may also be a compound that, in addition to VA units, further contains non-vinyl alcohol units (structural units derived from monomers other than vinyl alcohol, hereinafter also referred to as "non-VA units"). There are no particular limitations on non-VA units; examples include structural units derived from ethylene, vinyl acetate, vinyl propionate, vinyl hexanoate, 2-butenediol, etc. When a polymer containing structural units derived from vinyl alcohol contains non-VA units, it may contain only one type of non-VA unit, or it may contain two or more types of non-VA units. In compounds containing VA units in their structure, the proportion of the number of VA units to the total number of repeating units is not particularly limited, but preferably 50% or more, more preferably 65% ​​or more, further preferably 70% or more, and particularly preferably 75% or more (up to 100%).

[0049] Examples of water-soluble polymers having alcoholic hydroxyl groups in the side chain include, for example, preferably at least one selected from the group consisting of polyvinyl alcohol, polyvinyl alcohol derivatives (polyvinyl alcohol derivatives having alcoholic hydroxyl groups in the side chain), copolymers of ethylene alcohol with other monomers (polymers of ethylene alcohol with alcoholic hydroxyl groups in the side chain and other monomers), and derivatives of the above copolymers (derivatives of copolymers of ethylene alcohol with alcoholic hydroxyl groups in the side chain and other monomers).

[0050] The degree of saponification of polyvinyl alcohol is not particularly limited, but preferably 50 mol% or more, more preferably 65 mol% or more, even more preferably 70 mol% or more, and especially preferably 75 mol% or more (up to 100 mol%).

[0051] As a polyvinyl alcohol derivative, examples include, for instance, modified polyvinyl alcohol. Modified polyvinyl alcohol comprises a structure in which part of the alcoholic hydroxyl group of the ethylene alcohol unit, which is a non-VA unit, is replaced by other functional groups (hereinafter also referred to as "modified VA unit").

[0052] There are no particular limitations on the modified polyvinyl alcohol (PVA), and examples include, for instance, carboxyl-modified PVA, sulfonic acid-modified PVA, phosphoric acid-modified PVA, silanol-modified PVA, epoxy-modified PVA, acetoacetyl-modified PVA, nitrile-modified PVA, pyrrolidone-modified PVA, siloxane-modified PVA, amino-modified PVA, and grade 4 amino-modified PVA. Furthermore, there are no particular limitations on the modified PVA, and examples include, for instance, compounds obtained by cyclizing PVA (e.g., polyvinyl butyral, polyvinyl propionaldehyde, polyvinyl acetal, polyvinyl formaldehyde, etc.).

[0053] As a derivative of a copolymer of vinyl alcohol and other monomers, there are no particular limitations. Examples include, for example, structural units derived from ethylene, structural units derived from vinyl ethers having long-chain alkyl groups, structural units derived from compounds having at least one of acrylonitrile and methacrylonitrile, etc., in addition to VA units and modified VA units.

[0054] Furthermore, as a water-soluble polymer having alcoholic hydroxyl groups in the side chain, a water-soluble polymer that does not have a lactam structure and has alcoholic hydroxyl groups in the side chain is preferred.

[0055] From these perspectives, as a water-soluble polymer having alcoholic hydroxyl groups in the side chain, polyvinyl alcohol and modified polyvinyl alcohol are preferred, polyvinyl alcohol and sulfonic acid modified polyvinyl alcohol are even more preferred, and polyvinyl alcohol is particularly preferred.

[0056] By using these compounds, the ratio of the grinding speed of a specific material (e.g., germanium-containing material) and the grinding speed between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials) can be made into a better range.

[0057] The weight-average molecular weight of the water-soluble polymer having alcoholic hydroxyl groups in the side chain is not particularly limited, but preferably 1,000 or more, more preferably 3,000 or more, and even more preferably 8,000 or more. Furthermore, the weight-average molecular weight of the water-soluble polymer having alcoholic hydroxyl groups in the side chain is not particularly limited, but preferably 1,000,000 or less, more preferably 100,000 or less, and even more preferably 50,000 or less. Within such a range, the ratio of grinding speeds between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials) can be within a more favorable range.

[0058] The weight-average molecular weight of a water-soluble polymer having alcoholic hydroxyl groups in its side chain can be determined by gel permeation chromatography (GPC) using poly(vinyl alcohol) (manufactured by Sigma-Aldrich) as a standard material under the following conditions.

[0059] Apparatus: Manufactured by Tosoh Corporation; Model: HLC-8320GPC; Column: OHpak SB-806HQ+SB-803 HQ (Shodex (registered trademark), Showa Denko Corporation); Effluent: 0.1 M NaCl aqueous solution; Flow rate: 1 mL / min; Detector: LS laser light scattering detector, Shodex RI detector; Oven temperature: 40℃; Injection volume: 100 μl.

[0060] Water-soluble polymers with alcoholic hydroxyl groups in their side chains can be commercially available or synthetic products.

[0061] Water-soluble polymers with alcoholic hydroxyl groups in their side chains can be used alone or in combination of two or more.

[0062] The concentration of the water-soluble polymer having an alcoholic hydroxyl group in the side chain in the grinding composition (mass (g) of the water-soluble polymer having an alcoholic hydroxyl group in the side chain in 1L of the grinding composition) is not particularly limited, but preferably 0.01 g / L or more, more preferably 0.05 g / L or more, further preferably 0.1 g / L or more, and especially preferably 0.3 g / L or more. Within such a range, the ratio of grinding speeds between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials) can be within a more favorable range. Furthermore, the concentration of the water-soluble polymer having an alcoholic hydroxyl group in the side chain in the grinding composition (mass (g) of the water-soluble polymer having an alcoholic hydroxyl group in the side chain in 1L of the grinding composition) is not particularly limited, but preferably 10 g / L or less, more preferably 5 g / L or less, further preferably 1 g / L or less, and especially preferably 0.8 g / L or less. If such a range is achieved, the ratio of the grinding speed of a specific material (e.g., germanium-containing materials) and the grinding speed between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials) can be within a better range.

[0063] [Water-soluble polymer having an endogenous amine structure] A grinding composition according to an embodiment of the present invention may contain a water-soluble polymer having an endogenous amine structure, but preferably does not contain a water-soluble polymer having an endogenous amine structure. By substantially not containing a water-soluble polymer having an endogenous amine structure, the effects of the present invention can be further improved.

[0064] In this specification, the phrase "substantially does not contain water-soluble polymers with an endorheic amine structure" means that the concentration of water-soluble polymers with an endorheic amine structure in the grinding composition (the mass of water-soluble polymers with an endorheic amine structure relative to the total mass of the grinding composition) is less than 1 ppm by mass. An embodiment of the grinding composition of the present invention does not contain water-soluble polymers with an endorheic amine structure; that is, it is particularly preferred that the concentration of water-soluble polymers with an endorheic amine structure in the grinding composition is 0 ppm by mass.

[0065] Examples of "endolaminar structure" in this specification include, for example, β-endolaminar structure, γ-endolaminar structure, δ-endolaminar structure, ε-caprolactam structure, and other structures. Examples of water-soluble polymers having an endolainar structure include, for example, water-soluble polymers containing structural units derived from monomers containing an endolainar structure. Furthermore, in this specification, "monomers containing an endolainar structure" includes monomers having a polymerizable group (e.g., vinyl group) on the nitrogen atom of the endolainar.

[0066] As a water-soluble polymer having an endogenous amide structure, there are no particular limitations; examples include, for instance, homopolymers or copolymers of monomers containing an endogenous amide structure, and copolymers of monomers containing an endogenous amide structure with other monomers. As for other monomers, there are no particular limitations; examples include, for instance, vinyl alcohol, vinyl acetate, etc. The type of copolymer is not particularly limited; examples include, for instance, block copolymers, random copolymers, graft copolymers, and other types of copolymers.

[0067] As a specific example of a water-soluble polymer having an endorheic amine structure, homopolymers (polyendoamines) containing monomers with an endorheic amine structure can be listed. There are no particular limitations on the polyendoamines; examples include, for instance, polyvinylpyrrolidone (PVP), polyvinylcaprolactone, polyvinylpentylamine, polyvinyllauronylamine, and polyvinylpiperidone.

[0068] The lower limit of the weight average molecular weight of water-soluble polymers having an endogenous amide structure is not particularly limited, and examples include, for example, 1,000 or more, 5,000 or more, 10,000 or more, etc. Furthermore, the upper limit of the weight average molecular weight of water-soluble polymers having an endogenous amide structure is not particularly limited, and examples include, for example, 2,800,000 or less, 1,200,000 or less, 50,000 or less, etc. Also, the method for determining the weight average molecular weight of water-soluble polymers having an endogenous amide structure is the same as the method described above for determining the weight average molecular weight of water-soluble polymers having an endogenous amide structure when the side chain of the water-soluble polymer does not have an alcoholic hydroxyl group. Furthermore, the method is the same as the method described above for determining the weight average molecular weight of water-soluble polymers having an endogenous amide structure when the side chain of the water-soluble polymer has an alcoholic hydroxyl group.

[0069] When the grinding composition of an embodiment of the present invention substantially does not contain a water-soluble polymer having an endogenous amine structure, the water-soluble polymer that does not have an alcoholic hydroxyl group in the side chain is preferably a water-soluble polymer that does not have an endogenous amine structure and does not have an alcoholic hydroxyl group in the side chain.

[0070] Furthermore, when the grinding composition of an embodiment of the present invention does not substantially contain a water-soluble polymer having an endogenous amine structure, the water-soluble polymer having an alcoholic hydroxyl group in the side chain is preferably a water-soluble polymer that does not have an endogenous amine structure and has an alcoholic hydroxyl group in the side chain.

[0071] [Polycarboxylic acid (salt)] A grinding composition according to one embodiment of the present invention comprises a polycarboxylic acid (salt). The polycarboxylic acid (salt) can enhance the grinding speed of a specific material.

[0072] In this specification, the term "polycarboxylic acid (salt)" means that the polycarboxylic acid can be the polycarboxylic acid itself or a salt of the polycarboxylic acid. Furthermore, the term "containing polycarboxylic acid (salt)" means containing at least one of the polycarboxylic acid and polycarboxylic acid salt (polycarboxylic acid, polycarboxylic acid salt, or both).

[0073] There are no particular restrictions on the polycarboxylic acid (salt), and examples can be listed, such as known carboxylic acids and known carboxylate salts. Among them, dicarboxylic acids, salts of dicarboxylic acids, tricarboxylic acids, and salts of tricarboxylic acids are preferred as polycarboxylic acids (salts), and tricarboxylic acids and salts of tricarboxylic acids are even more preferred.

[0074] Furthermore, polycarboxylic acids (salts) are preferably those containing a hydroxyl group in the molecule. There are no particular limitations on dicarboxylic acids or their salts, and examples include, for instance, oxalic acid, malonic acid, succinic acid, adipic acid, pimelic acid, 2-pentenic acid, methylene succinic acid (iconic acid), allyl malonic acid, isopropyl succinic acid, maleic acid, fumaric acid, citrate, mesocarboxylic acid, 2,4-hexadienoic acid, ethynyl succinic acid, glutaric acid, 2,5-furanic acid, phthalic acid, isophthalic acid, terephthalic acid, malic acid, hydroxymalonic acid, tartaric acid, etc. There are no particular limitations on tricarboxylic acids or their salts, and examples include, for instance, 1,2,3-propanetricarboxylic acid, aconitic acid, 1,3,5-benzenetricarboxylic acid (trimethylbenzene), trimellitic acid, citric acid, isocitrate, muscaric acid, etc. There are no particular restrictions on the tetravalent or higher carboxylic acids that constitute polycarboxylic acids or their salts, and examples can be given, such as 1,2,3,4-butanetetracarboxylic acid, benzotetracarboxylic acid, benzopentacarboxylic acid, benzohexacarboxylic acid, etc.

[0075] From these perspectives, as a polycarboxylic acid (salt), for example, malic acid, salts of malic acid, hydroxymalonic acid, salts of hydroxymalonic acid, tartaric acid, salts of tartaric acid, citric acid, salts of citric acid, isocitric acid, salts of isocitric acid, muscarinic acid, salts of muscarinic acid are preferred, citric acid, salts of citric acid, isocitric acid, salts of isocitric acid, muscarinic acid, salts of muscarinic acid are even more preferred, and citric acid, salts of citric acid are even more preferred.

[0076] By using these polycarboxylic acids (salts), it is possible to make the ratio of the grinding speed of a specific material (e.g., germanium-containing materials) and the grinding speed between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials) into a better range.

[0077] As a polycarboxylic acid (salt), a salt of a polycarboxylic acid is preferred. A salt of a polycarboxylic acid can be a salt consisting of all the carboxyl groups of the polycarboxylic acid, or a salt consisting of only a portion of the carboxyl groups of the polycarboxylic acid, but is more preferably a salt consisting of only a portion of the carboxyl groups of the polycarboxylic acid.

[0078] There are no particular restrictions on the types of salts; examples can be given, such as known types of salts. Specific examples include alkali metal salts, salts of Group 2 elements, and ammonium salts. Among these, ammonium salts are preferred.

[0079] By using these polycarboxylic acid salts, it is possible to make the ratio of the grinding speed of a specific material (e.g., germanium-containing materials) and the grinding speed between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials) into a better range.

[0080] From these perspectives, as polycarboxylic acids (salts), ammonium salts of dicarboxylic acids and tricarboxylic acids are preferred; ammonium salts of malic acid, hydroxymalonic acid, tartaric acid, citric acid, isocitrate, and pinamic acid are even more preferred; ammonium salts of citric acid, isocitrate, and pinamic acid are further preferred; and ammonium salts of citric acid are particularly preferred. Furthermore, as ammonium salts of citric acid, diammonium hydrogen citrate, triammonium citrate, and diammonium dihydrogen citrate are preferred, with diammonium hydrogen citrate being even more preferred.

[0081] Furthermore, polycarboxylic acids (salts) can also function as pH adjusters as described below.

[0082] Polycarboxylic acid (salts) can be commercially available or synthetic.

[0083] A polycarboxylic acid (salt) can be used alone or in combination with two or more.

[0084] The concentration of the polycarboxylic acid (salt) in the grinding composition (mass (g) of the polycarboxylic acid (salt) in 1L of the grinding composition) is not particularly limited, but preferably 0.01 g / L or more, more preferably 0.05 g / L or more, further preferably 0.1 g / L or more, and especially preferably 0.5 g / L or more. If it is within such a range, the grinding speed of a particular material (e.g., germanium-containing materials, etc.) will be further increased. Furthermore, the ratio of grinding speeds between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials, etc.) can be within a more favorable range. Furthermore, the concentration of the polycarboxylic acid (salt) in the grinding composition (mass (g) of the polycarboxylic acid (salt) in 1L of the grinding composition) is not particularly limited, but preferably 10 g / L or less, more preferably 5 g / L or less, further preferably 3 g / L or less, and especially preferably 1.5 g / L or less. If it is within such a range, the grinding speed of a particular material (e.g., germanium-containing materials) can be within a better range.

[0085] [Oxidizing Agent] A grinding composition according to one embodiment of the present invention includes an oxidizing agent. The oxidizing agent can increase the grinding speed of a particular material.

[0086] There are no particular limitations on the oxidant, but for example, an oxidant having a standard electrode potential of 0.3 V or higher is preferred. By using such an oxidant, the ratio of the grinding speed of a specific material (e.g., germanium-containing materials) and the grinding speed between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials) can be made into a better range. There are no particular limitations on the upper limit of the aforementioned standard electrode potential, but it is preferred to be 3.0 V or lower, 2.5 V or lower, or 2.0 V or lower. There are no particular limitations on the oxidant having a standard electrode potential of 0.3 V or higher, and examples include, for example, hydrogen peroxide, sodium peroxide, barium peroxide, organic oxidants, ozone water, silver (II) salts, iron (III) salts, etc. Furthermore, examples include, for instance, permanganic acid, chromic acid, dichromic acid, peroxydisulfuric acid, peroxyphosphoric acid, peroxysulfuric acid, peroxyboric acid, peroxyformic acid, peracetic acid, perbenzoic acid, perphthalic acid, hypochlorous acid, hypobromic acid, hypoiodic acid, chloric acid, chlorous acid, perchloric acid, bromic acid, iodic acid, periodic acid, sulfuric acid, persulfate, dichloroisocyanuric acid, and the salts mentioned above. Among these, hydrogen peroxide, ammonium persulfate, periodic acid, hypochlorous acid, and sodium dichloroisocyanurate are preferred, with hydrogen peroxide being even more desirable.

[0087] Furthermore, the so-called standard electrode potential refers to the electrode potential when all chemical species participating in the oxidation reaction are in a standard state, and is represented by the following mathematical formula 1.

[0088] [Mathematical Formula 1] E0 = -ΔG0 / nF = (RT / nF) lnK... Mathematical Formula 1

[0089] In mathematical formula 1, E0 is the standard electrode potential; ΔG0 is the standard Gibbs energy change of the oxidation reaction; K is its equilibrium constant (the equilibrium constant when the oxidant causes the oxidation reaction); F is the Faraday constant (here, the Faraday constant F is the product of the elementary charge (1.602 × 10⁻¹⁹ [coulombs]) and the Avogadro constant NA (6.022 × 10²³ [mol⁻¹]): 96485 [coulombs / moles]); R is the mole gas constant (where the mole gas constant R is the product of the Boltzmann constant k and the Avogadro constant NA: 8.314 [J·K⁻¹·mol⁻¹]); T is the absolute temperature [K]; n is the number of electrons participating in the oxidation reaction. Also, ln is the natural logarithm with the Nepe number e (≈2.718) as the base. As can be seen from mathematical formula 1, since the standard electrode potential varies with temperature, the standard electrode potential at 25°C is used in this specification. Furthermore, the standard electrode potential for aqueous solutions is described, for example, in the 4th edition of the Handbook of Chemistry (Basic Edition) II, pp. 464-468 ​​(edited by the Chemical Society of Japan).

[0090] Oxidizing agent, either commercially available or synthetic products can be used.

[0091] Oxidizing agents can be used alone or in combination of two or more.

[0092] The concentration of the oxidant in the grinding composition (mass (g) of the oxidant in 1L of the grinding composition) is not particularly limited, but preferably 0.1 g / L or more, more preferably 1 g / L or more, further preferably 6 g / L or more, and especially preferably 10 g / L or more. If it is within such a range, the grinding speed of a particular material (e.g., a germanium-containing material, etc.) will be further increased. Furthermore, the ratio of grinding speeds between two or more different materials (e.g., between a germanium-containing material and a silicon-containing compound other than a germanium-containing material, etc.) can be within a more favorable range. Furthermore, the concentration of the oxidant in the grinding composition (mass (g) of the oxidant in 1L of the grinding composition) is not particularly limited, but preferably 100 g / L or less, more preferably 50 g / L or less, further preferably 30 g / L or less, and especially preferably 20 g / L or less. If such a range is achieved, then the ratio of the grinding speed of a specific material (e.g., germanium-containing material) and the grinding speed between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials) can be within a better range.

[0093] [pH Adjuster] The grinding composition of one embodiment of the present invention may further include a pH adjuster. The pH adjuster can adjust the pH value of the grinding composition to a desired value.

[0094] Furthermore, in this specification, the term "pH adjuster" refers to a compound other than the aforementioned polycarboxylic acid (salt) that has the function of adjusting the pH of the grinding composition.

[0095] As a pH adjuster, there are no particular restrictions, and it can be used, for example, with known acids or bases.

[0096] Examples of acids that can be used as pH adjusters include, for example, inorganic acids, organic acids, and chelating agents. Specific examples of inorganic acids used as pH adjusters are not particularly limited, and examples include hydrochloric acid (HCl), sulfuric acid (H₂SO₄), nitric acid (HNO₃), hydrofluoric acid (HF), boric acid (H₃BO₃), carbonic acid (H₂CO₃), hypophosphorous acid (H₃PO₂), phosphorous acid (H₃PO₃), and phosphoric acid (H₃PO₄). Examples of organic acids used as pH adjusters are not particularly limited, and examples include monocarboxylic acids and organic sulfuric acids. Specific examples of monocarboxylic acids are not particularly limited and can include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, hexanoic acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid, 4-methylvaleric acid, heptanoic acid, 2-methylhexanoic acid, octanoic acid, 2-ethylhexanoic acid, benzoic acid, glycolic acid, salicylic acid, glyceric acid, lactic acid, glyoxylic acid, 2-furancarboxylic acid, 3-furancarboxylic acid, 2-tetrahydrofurancarboxylic acid, methoxyacetic acid, methoxyphenylacetic acid, phenoxyacetic acid, etc. Furthermore, specific examples of organic sulfuric acids are not particularly limited and can include methanesulfonic acid, ethanesulfonic acid, hydroxyethylsulfonic acid, etc. Bases used as pH adjusters can include, for example, alkali metal hydroxides or their salts, group 2 element hydroxides or their salts, quaternary ammonium hydroxide or its salts, ammonia, amines, etc. Specific examples of alkali metals include potassium and sodium. Specific examples of group 2 elements include magnesium and calcium.

[0097] Among these, inorganic acids are preferred, hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid are preferred, sulfuric acid and nitric acid are even more preferred, and nitric acid is even more preferred. By using such a pH adjuster, the ratio of the grinding speed of a specific material (e.g., germanium-containing materials) and the grinding speed between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials) can be within a better range.

[0098] pH adjuster, commercially available products or synthetic products can be used.

[0099] pH adjuster, one can be used alone or two or more can be used in combination.

[0100] The concentration of the pH adjuster is not particularly limited, but it is preferred to make the pH of the grinding composition less than 6, and more preferably to make the pH value within the preferred pH range described later.

[0101] [pH] The pH of the grinding composition of one embodiment of the present invention is less than 6.

[0102] The lower limit of the pH of the grinding composition is not particularly limited, but it is preferably 1 or higher, more preferably 2 or higher, and even more preferably 2.5 or higher. If it is within such a range, the grinding speed of a specific material (e.g., germanium-containing materials) will be further increased. Furthermore, the ratio of grinding speeds between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials) can be within a better range. Furthermore, corrosion is less likely to occur, making it suitable for grinding objects containing various materials. Furthermore, safety is improved, and operation is easier. Furthermore, the upper limit of the pH of the grinding composition is not particularly limited as long as it is less than 6, but it is preferably 5 or lower, and more preferably 4 or lower. If it is within such a range, the grinding speed of a specific material (e.g., germanium-containing materials) and the ratio of grinding speeds between two or more different materials (e.g., between germanium-containing materials and silicon-containing compounds other than germanium-containing materials) can be within a better range. Furthermore, the pH value of the grinding composition can be evaluated using a pH meter (manufactured by Horiba Manufacturing Co., Ltd.; LAQUA (registered trademark)).

[0103] [Dispersion Medium] The grinding composition of one embodiment of the present invention may further include a dispersion medium. The dispersion medium plays a role in dispersing or dissolving the components in the grinding composition.

[0104] The water content in the dispersion medium is not particularly limited, but it is preferably 50% by mass or more relative to the total mass of the dispersion medium, more preferably 90% by mass or more, and even more preferably water alone. As for the water, from the viewpoint of preventing contamination of the object being ground and preventing hindering the action of other components, it is preferable to use water that contains as few impurities as possible. For example, water with a total transition metal ion content of 100 ppb by mass or less is preferred. Here, the purity of the water can be improved by, for example, using ion exchange resin to remove residual ions, using a filter to remove foreign matter, distillation, etc. Specifically, it is preferable to use, for example, deionized water (ion-exchanged water), pure water, ultrapure water, distilled water, etc.

[0105] As a dispersion medium, it may further contain an organic solvent. There are no particular limitations on the organic solvent, and known organic solvents may be used.

[0106] Organic solvents may be used alone or in combination of two or more.

[0107] [Other Components] The grinding composition of one embodiment of the present invention may further include other components besides those described above. Examples of other components include, for example, known components used in grinding compositions. Examples of other components include, for example, amino acids, chelating agents, metal corrosion inhibitors, preservatives, antifungal agents, etc.

[0108] [Method for Manufacturing a Grinding Composition] A method for manufacturing a grinding composition according to an embodiment of the present invention is not particularly limited as long as it includes the step of mixing abrasive particles, a water-soluble polymer without alcoholic hydroxyl groups in its side chain, a polycarboxylic acid (salt), and an oxidizing agent, and the pH of the resulting grinding composition is less than 6. In this case, the water-soluble polymer with alcoholic hydroxyl groups in its side chain, a pH adjuster, a dispersion medium, and other components may be further mixed as needed. The mixing method for each component is not particularly limited, and known methods can be used appropriately. Furthermore, the mixing temperature is not particularly limited, but is generally preferred between 10°C and 40°C; heating may be used to increase the dissolution rate. Furthermore, the mixing time is not particularly limited.

[0109] [Grinding Object] The grinding object applicable to the grinding composition of one embodiment of the present invention is not particularly limited, and examples can be given, such as known grinding objects used in the field of CMP.

[0110] There are no particular limitations on the object to be polished. For example, a planar component is preferred, a substrate is more preferred, and a semiconductor substrate is even more preferred. There are no particular limitations on the substrate, and examples include, for instance, a substrate formed from a single film layer, a substrate having a structure with two or more film layers deposited, and a substrate having a structure with two or more substances arranged on its surface. Among these, a substrate having a structure with two or more substances arranged on its surface is preferred, a substrate having a structure with two or three substances arranged on its surface is more preferred, and a substrate having a structure with two substances alternately arranged on its surface is even more preferred.

[0111] There are no particular limitations on the materials used to form the grinding object of the grinding composition applicable to one embodiment of the present invention. However, the grinding object of the grinding composition applicable to one embodiment of the present invention is preferably composed of a material containing at least one of silicon and germanium, more preferably containing a germanium-containing material, further preferably containing a germanium-containing material represented by SiXGe(1-X) (wherein 0≤X<1), and even more preferably containing silicon-germanium (represented by SiYGe(1-Y) (wherein 0<Y<1)). It is particularly preferred to contain a material represented by SiZGe(1-Z) (wherein 0.01≤Z<1). Here, Z is preferably 0.05 or more and 0.95 or less; more preferably 0.1 or more and 0.90 or less. By applying the grinding composition of one embodiment of the present invention to a grinding object containing these materials, the grinding speed of a particular material can be made into a better range.

[0112] Furthermore, the grinding object suitable for the grinding composition of one embodiment of the present invention preferably contains two or more materials. There are no particular limitations on the grinding object containing two or more materials, but it is preferable to include a grinding object containing a germanium-containing material and a silicon-containing compound other than a germanium-containing material. That is, the grinding composition of one embodiment of the present invention is preferably used for grinding grinding objects containing a germanium-containing material and a silicon-containing compound other than a germanium-containing material. Here, there are no particular limitations on the silicon-containing compound other than a germanium-containing material; examples include, for example, materials having silicon-oxygen bonds, materials having silicon-silicon bonds, materials having silicon-nitrogen bonds, etc. Furthermore, there are no particular limitations on the material having silicon-oxygen bonds; examples include, for example, silicon oxide, BD (black diamond: SiOCH), FSG (fluorosilicate glass), HSQ (hydrosilicon sesquioxane), CYCLOTENE, SiLK, MSQ (methylsilicon sesquioxane), etc. Furthermore, there are no particular limitations on materials containing silicon-silicon bonds; examples include polycrystalline silicon (poly-Si), amorphous silicon, single-crystal silicon, n-type doped single-crystal silicon, and p-type doped single-crystal silicon. Similarly, there are no particular limitations on materials containing silicon-nitrogen bonds; examples include silicon nitride (SiN) and silicon carbonitride (SiCN). Among these, materials containing silicon compounds other than germanium-containing materials, those with silicon-oxygen bonds and those with silicon-silicon bonds are preferred, with silicon oxide and polycrystalline silicon being even more preferred.

[0113] By applying the grinding composition of one embodiment of the present invention to grinding objects comprising two or more materials, the grinding speed of a particular material can be made into a better range. Furthermore, the ratio of grinding speeds between two or more different materials can be made into a better range.

[0114] Therefore, the grinding object of the grinding composition applicable to one embodiment of the present invention preferably includes at least one of germanium-containing material and material having silicon-oxygen bonds and material having silicon-silicon bonds (material having silicon-oxygen bonds, material having silicon-silicon bonds, or both); more preferably includes germanium silicon and at least one of silicon oxide and polycrystalline silicon (silicon oxide, polycrystalline silicon, or both); and even more preferably includes germanium silicon, silicon oxide, and polycrystalline silicon.

[0115] Furthermore, the grinding object of the grinding composition applicable to one embodiment of the present invention may also contain other materials besides those described above. There are no particular limitations on other materials; examples include, for instance, metals such as copper, aluminum, hafnium, cobalt, nickel, titanium, tungsten, and their alloys. Furthermore, examples include, for instance, metal oxides such as aluminum oxide. And examples include, for instance, metal nitrides such as titanium nitride and tantalum nitride.

[0116] Furthermore, materials containing at least one of silicon and germanium, germanium-containing materials, silicon-containing compounds other than germanium-containing materials, and other materials may each be used alone or in combination of two or more.

[0117] [Grinding Method and Method for Manufacturing a Grinded Substrate] Another embodiment of the present invention relates to a grinding method in which the above-described grinding composition is used to grind a grinding object. Details of the grinding composition used and the applicable grinding object in this embodiment of the present invention are respectively described above. Therefore, as a preferred example of a grinding object in this embodiment of the present invention, grinding objects including germanium-containing materials and silicon-containing compounds other than germanium-containing materials can be listed.

[0118] In one embodiment of the grinding method of the present invention, there are no particular limitations on the details of the grinding method, grinding conditions and grinding apparatus, etc., and known methods, conditions and apparatus can be used.

[0119] As the grinding apparatus used in the grinding step, a grinding apparatus used in a general chemical mechanical grinding process can be used. Such a grinding apparatus is provided with a carrier for holding the object to be ground, a motor that can change the rotation speed, and a grinding disc on which a grinding pad (or grinding cloth) can be attached.

[0120] There are no particular limitations on the type of abrasive pad that can be used, such as general non-woven fabric, polyurethane resin pads (polyurethane pads), and porous fluoropolymer pads. In addition, the abrasive pad can be grooved as needed, so that the abrasive composition can accumulate in the grooves of the abrasive pad.

[0121] There are no particular restrictions on the parameters of the grinding step, and they can be adjusted according to actual needs. The rotational speed of the grinding disc is not particularly limited and can be adjusted, for example, to 10–500 rpm (0.2–8.3 s⁻¹, also, 60 rpm = 1 s⁻¹. The same applies below); the rotational speed of the carrier is not particularly limited and can be adjusted, for example, to 10–500 rpm (0.2–8.3 s⁻¹). Furthermore, the pressure applied to the object being ground (grinding pressure) is not particularly limited and can be adjusted, for example, to 0.1–10 psi (0.7–68.9 kPa, also, 1 psi = 6894.76 Pa. The same applies below); 2–3 psi (13.8–20.7 kPa) is preferred. The grinding time is not particularly limited and can be adjusted, for example, from 10 to 180 seconds, preferably from 20 to 150 seconds, and even more preferably from 30 to 120 seconds. The flow rate of the grinding composition is not particularly limited and can be adjusted, for example, from 10 to 500 ml / min. The method of supplying the grinding composition to the grinding pad is also not particularly limited; for example, a continuous supply method using a pump or the like can be employed.

[0122] After the grinding step is completed, the grinding object can be washed in water and dried by blowing away the water droplets attached to the grinding object using a rotary dryer or the like.

[0123] Another embodiment of the present invention relates to a method for manufacturing a polished substrate, which includes polishing the substrate using the above-described polishing composition, or polishing a polishing object that is a substrate by a polishing method. In the method for manufacturing a polished substrate according to one embodiment of the present invention, the polishing composition used, the applicable polishing object, and the details of the polishing method used are each described above. In the method for manufacturing a polished substrate according to one embodiment of the present invention, as a preferred example of a substrate, substrates containing germanium materials and silicon-containing compounds other than germanium materials can be cited. Although embodiments of the present invention have been described in detail, these are merely illustrative and exemplary examples, not limiting examples, and it should be understood that the scope of the present invention should be interpreted in accordance with the appended claims.The present invention includes the following embodiments and forms: [1] A grinding composition comprising abrasive particles, a water-soluble polymer without alcoholic hydroxyl groups in its side chain, a polycarboxylic acid (salt), and an oxidant, and having a pH less than 6; [2] The grinding composition described in [1] above further comprising a water-soluble polymer having alcoholic hydroxyl groups in its side chain; [3] The grinding composition described in [2] above, wherein the water-soluble polymer having alcoholic hydroxyl groups in its side chain is at least one selected from the group consisting of polyvinyl alcohol, polyvinyl alcohol derivatives, copolymers of vinyl alcohol and other monomers, and derivatives of the copolymers above; [4] The grinding composition described in any one of [1] to [3] above, wherein the polycarboxylic acid (salt) has hydroxyl groups in its molecule; [5] The grinding composition described in any one of [1] to [4] above, wherein the water-soluble polymer without alcoholic hydroxyl groups in its side chain contains polyolefin oxygen groups represented by the following formula (I): [Chemical Formula 2] In the above formula (I), X is an integer of 2 or more, and n is an integer of 2 or more; [6] The abrasive composition described in any of [1] to [5] above, wherein the water-soluble polymer that does not have an alcoholic hydroxyl group in its side chain is at least one selected from the group consisting of polyethylene glycol, polypropylene glycol, polybutylene glycol, polypentylene glycol, polyhexanediol, polyheptanediol, polyoctylene glycol, polynonanediol, and polydecanediol; [7] The abrasive composition described in any of [1] to [6] above, wherein the weight average molecular weight of the water-soluble polymer that does not have an alcoholic hydroxyl group in its side chain is less than 1,000; [8] The abrasive composition described in any of [1] to [7] above, wherein the abrasive particles are abrasive particles with organic acid functional groups covalently bonded to their surface; [9] A polishing composition as described in any one of [1] to [8] above, used for polishing a polishing object containing a germanium-containing material and a silicon-containing compound other than a germanium-containing material;

[10] A polishing method, using a polishing composition as described in any one of [1] to [9] above to polish a polishing object;

[11] A polishing method as described in

[10] above, wherein the polishing object contains a germanium-containing material and a silicon-containing compound other than a germanium-containing material;

[12] A method for manufacturing a polished substrate, comprising polishing a substrate using a polishing composition as described in any one of [1] to [8] above, or comprising polishing the polishing object as a substrate by a polishing method as described in

[10] or

[11] above;

[13] A method for manufacturing a polished substrate as described in

[12] above, wherein the substrate contains a germanium-containing material and a silicon-containing compound other than a germanium-containing material. [Examples].

[0124] The present invention will be described in more detail using the following embodiments and comparative examples. However, the technical scope of the present invention is not limited to the following embodiments. Also, unless otherwise stated, "%" and "parts" mean "mass %" and "parts by mass," respectively.

[0125] <Preparation of the Grinding Composition> The grinding particles, a water-soluble polymer without alcoholic hydroxyl groups in its side chain, a water-soluble polymer with alcoholic hydroxyl groups in its side chain, a polycarboxylic acid (salt) or a comparative component thereof, an oxidant, and a pH adjuster were mixed in ultrapure water as a dispersion medium (mixing temperature: approximately 25°C, mixing time: approximately 10 minutes) according to the compositions shown in Tables 1 and 2 below to prepare the grinding compositions of the Examples and Comparative Examples. Furthermore, the concentration of the pH adjuster was set to achieve the pH values ​​shown in Tables 1 and 2 below. The pH value of the grinding composition was confirmed using a pH meter (manufactured by Horiba Manufacturing Co., Ltd.; LAQUA (registered trademark)) (the temperature of the grinding composition during pH measurement was 25°C). Furthermore, "-" in Tables 1 and 2 below indicates that this component is not added. Details of each component in Tables 1 and 2 below are described below.

[0126] [Abrasive Particles] . Colloidal silicon oxide with sulfonic acid groups immobilized on its surface (collloidal silicon oxide immobilized on its surface with sulfonic acid): (Primary average particle size: 35nm, secondary average particle size: 70nm, cocoon-shaped).

[0127] [Water-soluble polymers without alcoholic hydroxyl groups in the side chain] . PPG400: Polypropylene glycol (weight average molecular weight 400); . PPG700: Polypropylene glycol (weight average molecular weight 700); . TPG: Tripropylene glycol (polypropylene glycol with 3 repeating units, weight average molecular weight 192); Here, the molecules of PPG400, PPG700 and TPG each have the structure OH-[-CH2CH(CH3)O-]nH (n is the number of repeating units).

[0128] [Water-soluble polymers with alcoholic hydroxyl groups in the side chain] . PVA4000: Polyethylene (weight average molecular weight 4,000); . PVA10000: Polyvinyl alcohol (weight average molecular weight 10,000); . PVA22000: Polyvinyl alcohol (weight average molecular weight 22,000); . S-PVA: Sulfonic acid modified polyvinyl alcohol (weight average molecular weight 10,000).

[0129] [Polycarboxylic acids (salts) or their comparative components] .Citrate H(NH4)2: Diammonium hydrogen citrate (a salt of a polycarboxylic acid with a hydroxyl group in the molecule); .Maleic acid: (a polycarboxylic acid); .Ammonium acetate: (a salt of a monocarboxylic acid).

[0130] [Oxidizing agent] . Hydrogen peroxide: (31% by mass hydrogen peroxide solution, the values ​​shown in Tables 1 and 2 below are converted to the amount of hydrogen peroxide).

[0131] [pH Adjuster] . Nitric acid: (70% by mass aqueous solution of nitric acid, the values ​​shown in Tables 1 and 2 below are converted to the amount of nitric acid); . Sulfuric acid: (62.5% by mass aqueous solution of sulfuric acid, the values ​​shown in Tables 1 and 2 below are converted to the amount of sulfuric acid); . Acetic acid: (approximately 100% by mass solution).

[0132] [Table 1] Composition of the grinding composition Grinding Composition abrasive particles (Sulfoic acid immobilized on its surface colloidal silicon oxide) Water-soluble polymers with alcoholic hydroxyl groups in their side chains Water-soluble polymers that do not have alcoholic hydroxyl groups in their side chains Polycarboxylic acids (salts) Oxidizing agent (Hydrogen peroxide) pH regulator pH concentration (quality%) type concentration (g / L) type concentration (g / L) type concentration (g / L) concentration (g / L) type Example 1 1 PVA10000 0.5 PPG400 2.25 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 2.5 Example 2 1 PVA10000 0.5 PPG400 2.25 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 3.0 Example 3 1 PVA10000 0.5 PPG400 2.25 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 4.0 Example 4 1 PVA10000 0.5 PPG400 2.25 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 5.0 Comparative Example 1 0 PVA10000 0.5 PPG400 2.25 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 3.0 Example 5 0.5 PVA10000 0.5 PPG400 2.25 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 3.0 Example 6 2 PVA10000 0.5 PPG400 2.25 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 3.0 Example 7 1 - 0 PPG400 2.25 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 3.0 Example 8 1 PVA10000 0.1 PPG400 2.25 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 3.0 Example 9 1 PVA10000 1.0 PPG400 2.25 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 3.0 Comparative Example 2 1 PVA10000 0.5 - 0 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 3.0 Example 10 1 PVA10000 0.5 PPG400 1.00 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 3.0 Example 11 1 PVA10000 0.5 PPG400 3.00 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 3.0 Comparative Example 3 1 PVA10000 0.5 PPG400 2.25 - 0 12.4 Nitric acid 3.0 Example 12 1 PVA10000 0.5 PPG400 2.25 Diammonium hydrogen citrate 0.5 12.4 Nitric acid 2.7 Comparative Example 4 1 PVA10000 0.5 PPG400 2.25 Diammonium hydrogen citrate 1.0 0 Nitric acid 3.0 Example 13 1 PVA10000 0.5 PPG400 2.25 Diammonium hydrogen citrate 1.0 15.0 Nitric acid 3.0 Comparative Example 5 1 PVA10000 0.5 PPG400 2.25 ammonium acetate 1.0 12.4 Nitric acid 3.0

[0133] [Table 2] Composition of the grinding composition Grinding Composition abrasive particles (Sulfoic acid immobilized on its surface colloidal silicon oxide) Water-soluble polymers with alcoholic hydroxyl groups in their side chains Water-soluble polymers that do not have alcoholic hydroxyl groups in their side chains Polycarboxylic acids (salts) Oxidizing agent (Hydrogen peroxide) pH regulator pH concentration (quality%) type concentration (g / L) type concentration (g / L) type concentration (g / L) concentration (g / L) type Example 14 1 PVA10000 0.5 PPG400 2.25 Diammonium hydrogen citrate 1.0 12.4 sulfuric acid 3.0 Example 15 1 PVA10000 0.5 PPG400 2.25 Diammonium hydrogen citrate / Maleic acid 1.0 / 0.5 12.4 - 3.0 Example 16 1 PVA10000 0.5 PPG400 2.25 Diammonium hydrogen citrate 1.0 12.4 Acetic acid 3.0 Example 17 1 PVA4000 0.5 PPG400 2.25 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 3.0 Example 18 1 PVA22000 0.5 PPG400 2.25 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 3.0 Example 19 1 PVA10000 0.5 TPG 2.25 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 3.0 Example 20 1 PVA10000 0.5 PPG700 2.25 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 3.0 Example 21 1 S-PVA 0.5 PPG400 2.25 Diammonium hydrogen citrate 1.0 12.4 Nitric acid 3.0

[0134] <Evaluation> [Determination of Grinding Speed] Using the grinding composition obtained above, silicon germanium (SiGe) substrates (manufactured by Silicon Valley Microeletronic, Inc., specifically Si0.75Ge0.25), polycrystalline silicon (poly-Si) substrates (manufactured by Advanced Materials Technology, Inc.), and silicon oxide (SiO2) substrates (manufactured by Advanced Materials Technology, Inc.) were ground under the following grinding conditions, and the grinding speed during grinding was measured.

[0135] Grinding apparatus: Manufactured by Ebara Corporation; FREX300E Grinding pad: Polyurethane pad Grinding pressure: 1.0 psi (6.9 kPa) Disc rotation speed: 90 rpm (1.5 s⁻¹) Grinding head rotation speed: 90 rpm (1.5 s⁻¹) Grinding composition supply method: Flowing Grinding composition supply rate: 300 mL / min Grinding time: 60 seconds

[0136] The thickness of the object to be ground was measured before and after grinding using an optical interferometric film thickness measurement system (manufactured by Filmetrics; Filmetric F20). The grinding speed was calculated using the following formula. These results are shown in Table 3 below.

[0137] [Mathematical Formula 2] Grinding speed = {[Thickness before grinding] - [Thickness after grinding]} / [Processing time]

[0138] In the above formula, the unit of thickness is "Å" (10Å = 1 nm, the same below), the unit of processing time is "minute (min)", and the unit of grinding speed is "Å / nm". Furthermore, processing time specifically refers to grinding time.

[0139] Furthermore, in this evaluation, it was determined that if the polishing speed of the SiGe substrate is 30 Å / min (3.0 nm / min) or higher and 70 Å / min (7.0 nm / min) or lower, excellent results can be obtained.

[0140] The reason is that, in this evaluation, if the grinding speed of the SiGe substrate is 30 Å / min or higher, a good grinding effect can be obtained due to the high grinding efficiency of SiGe. On the other hand, when the grinding speed of the SiGe substrate is less than 30 Å / min, the grinding efficiency of SiGe is low, and therefore a sufficient grinding effect cannot be obtained. Furthermore, in this evaluation, if the grinding speed of the SiGe substrate is 70 Å / min or lower, the balance between the grinding speed of SiGe and the grinding speed of materials other than SiGe (poly-Si and SiO2 in this experiment) is excellent, and an excellent reduction effect on step difference and dishing depression can be expected. On the other hand, when the grinding speed of the SiGe substrate exceeds 70 Å / min, only the grinding speed of SiGe becomes too high, and the balance between the grinding speed of SiGe and the grinding speed of materials other than SiGe (poly-Si and SiO2 in this experiment) is lost, and a sufficient reduction effect on step difference and dishing depression cannot be expected.

[0141] Within the above range, from the viewpoint of reducing polishing efficiency, step size, and dish-shaped depressions, in this evaluation, it is determined that if the polishing speed of the SiGe substrate is 35 Å / min (3.5 nm / min) or higher and 65 Å / min (6.5 nm / min) or lower, a better effect can be obtained; and if it is 40 Å / min (4.0 nm / min) or higher and 60 Å / min (6.0 nm / min) or lower, a particularly excellent effect can be obtained.

[0142] [Calculation of the selectivity ratio of polishing speed] Using the polishing speeds of the SiGe substrate, the poly-Si substrate, and the SiO2 substrate obtained above, the ratio of the polishing speed of the SiGe substrate to the polishing speed of the poly-Si substrate (selectivity ratio SiGe / polysilicon) and the ratio of the polishing speed of the SiGe substrate to the polishing speed of the SiO2 substrate (selectivity ratio SiGe / SiO2) were calculated. These results are shown in Table 3 below.

[0143] Furthermore, in this evaluation, it is determined that if the SiGe / poly-Si ratio and the SiGe / SiO2 ratio are 1.0 or more and 3.0 or less respectively, excellent results can be obtained.

[0144] The reason is that, in this evaluation, if the SiGe / poly-Si ratio and the SiGe / SiO2 ratio are each 1.0 or higher, the grinding effect of SiGe can be expected to be sufficient to construct the desired step difference. On the other hand, it is believed that when the SiGe / poly-Si ratio and the SiGe / SiO2 ratio are each less than 1.0, the grinding effect of SiGe is insufficient, and it is difficult to construct the desired step difference. Furthermore, in this evaluation, if the SiGe / poly-Si ratio and the SiGe / SiO2 ratio are each 3.0 or lower, the loss of SiGe is small, and it is expected to construct the desired step difference. On the other hand, it is believed that when the SiGe / poly-Si ratio and the SiGe / SiO2 ratio are each greater than 3.0, the grinding speed of SiGe becomes too high, the loss of SiGe becomes large, and it is difficult to construct the desired step difference.

[0145] Within the above range, from the viewpoint of constructing the desired step difference and the amount of SiGe loss, in this evaluation, it is determined that if the SiGe / poly-Si ratio and the SiGe / SiO2 ratio are each 1.2 or more and 2.0 or less, respectively, then a better effect can be obtained; it is determined that if the SiGe / poly-Si ratio and the SiGe / SiO2 ratio are each 1.4 or more and 1.7 or less, respectively, then a particularly excellent effect can be obtained.

[0146] Furthermore, in this evaluation, it was confirmed that if the SiGe / poly-Si ratio and the SiGe / SiO2 ratio are each 1.0 or higher, in addition to the effects mentioned above, the removal performance of the ground SiGe residue can also be improved. Moreover, in this evaluation, when the SiGe / poly-Si ratio and the SiGe / SiO2 ratio are each 1.2 or higher, the removal performance of the ground SiGe residue can be further improved; when the SiGe / poly-Si ratio and the SiGe / SiO2 ratio are each 1.4 or higher, the removal performance of the ground SiGe residue can be further improved.

[0147] Furthermore, in this evaluation, it is particularly desirable that both the SiGe / poly-Si ratio and the SiGe / SiO2 ratio are within the above-mentioned range.

[0148] [Table 3] Grinding speed and selectivity caused by the grinding composition Grinding Composition Grinding speed Selection ratio SiGe [Å / min] poly-Si [Å / min] SiO2 [Å / min] SiGe / poly-Si SiGe / SiO2 Example 1 37.0 22.0 25.0 1.68 1.48 Example 2 52.0 33.0 30.0 1.58 1.73 Example 3 53.6 45.9 28.5 1.17 1.88 Example 4 57.8 53.6 26.8 1.08 2.15 Comparative Example 1 4.1 5.0 0.7 0.82 5.86 Example 5 43.8 26.7 20.2 1.64 2.17 Example 6 68.3 60.9 49.9 1.12 1.37 Example 7 64.6 30.3 30.2 2.13 2.14 Example 8 62.1 31.9 30.2 1.95 2.07 Example 9 39.4 32.1 30.1 1.23 1.31 Comparative Example 2 120.7 81.7 33.9 1.48 3.56 Example 10 69.2 62.3 32.2 1.11 2.15 Example 11 32.1 23.6 28.9 1.36 1.11 Comparative Example 3 7.3 8.2 24.4 0.90 0.30 Example 12 30.7 23.1 27.3 1.32 1.12 Comparative Example 4 0 29.1 31.5 0 0 Example 13 63.2 45.8 29.8 1.38 2.12 Comparative Example 5 17.0 29.7 31.1 0.57 0.55 Example 14 47.0 31.2 29.9 1.51 1.57 Example 15 41.1 38.2 33.5 1.08 1.23 Example 16 39.4 36.7 32.6 1.07 1.21 Example 17 59.2 37.1 31.4 1.60 1.89 Example 18 46.1 23.2 29.9 1.99 1.54 Example 19 44.0 41.0 29.9 1.07 1.47 Example 20 32.8 25.6 21.0 1.28 1.56 Example 21 51.8 32.1 29.9 1.61 1.73

[0149] As described in Tables 1-3 above, the grinding compositions of Examples 1-21 contain abrasive particles, a water-soluble polymer without alcoholic hydroxyl groups in its side chains, a polycarboxylic acid (salt), and an oxidizing agent, and have a pH value of less than 6. Tables 1-3 above confirm that the grinding compositions of Examples 1-21 can achieve a moderately high grinding speed for SiGe, and can achieve a SiGe / poly-Si selectivity ratio and a SiGe / SiO2 selectivity ratio within a favorable range. These results indicate that the grinding compositions of Examples 1-21 are expected to have a high grinding efficiency in grinding objects containing SiGe, and excellent reduction effects on step and disc-shaped depressions in grinding objects containing SiGe and poly-Si, and grinding objects containing SiGe and SiO2.

[0150] On the other hand, it has been confirmed that the polishing composition of Comparative Example 1, which does not contain abrasive particles, the polishing composition of Comparative Example 2, which does not contain a water-soluble polymer without alcoholic hydroxyl groups in its side chains, the polishing compositions of Comparative Examples 3 and 5, which do not contain polycarboxylic acids (salts), and the polishing composition of Comparative Example 4, which does not contain an oxidant, have polishing speeds for SiGe substrates, selectivity ratios of at least one of SiGe / poly-Si and SiGe / SiO2 (selected from at least one of the groups consisting of polishing speeds for SiGe substrates, selectivity ratios of SiGe / poly-Si, and selectivity ratios of SiGe / SiO2) that are outside the range of excellent results. From these results, it can be seen that the polishing compositions of Comparative Examples 1 to 5 are not sufficiently efficient at polishing objects containing SiGe, or are not sufficiently effective at reducing steps and disc-shaped depressions in objects containing at least one of SiGe, poly-Si, and SiO2 (with poly-Si, SiO2, or both).

[0151] This application is based on Japanese Patent Application No. 2021-077571 filed on April 30, 2021 and Japanese Patent Application No. 2022-047909 filed on March 24, 2022, the disclosures of which are incorporated herein by reference in their entirety. [Simplified Explanation of the Diagram]

[0011] None.

Claims

1. A grinding composition comprising abrasive particles with organic acid functional groups covalently bonded to their surface, a water-soluble polymer without alcoholic hydroxyl groups in its side chain, a water-soluble polymer with alcoholic hydroxyl groups in its side chain, a polycarboxylic acid (salt), and an oxidizing agent, wherein the concentration of the water-soluble polymer without alcoholic hydroxyl groups in the grinding composition is 2 g / L or more and 20 g / L or less, and the pH is 4 or less.

2. The grinding composition as described in claim 1, wherein, The polishing composition has the following characteristics: the ratio of the polishing speed of the SiGe substrate to the polishing speed of the poly-Si substrate (selective ratio SiGe / poly-Si) is 1.0 or more and 3.0 or less, and the ratio of the polishing speed of the SiGe substrate to the polishing speed of the SiO2 substrate (selective ratio SiGe / SiO2) is 1.0 or more and 3.0 or less.

3. The grinding composition as described in claim 1 or 2, wherein, The abrasive particles whose functional groups of the organic acid are covalently bonded to their surface are silicon oxide abrasive particles with organic acid immobilized on their surface.

4. The grinding composition as described in claim 1 or 2, wherein, The concentration of the water-soluble polymer having an alcoholic hydroxyl group in the side chain in the above-mentioned grinding composition is 0.01 g / L or more and 10 g / L or less.

5. The grinding composition as claimed in claim 1 or 2 further comprises a pH adjuster, wherein the pH adjuster comprises an inorganic acid.

6. The grinding composition as described in claim 1 or 2, wherein, The weight average molecular weight of water-soluble polymers that do not have alcoholic hydroxyl groups in the above side chains is above 200.

7. The grinding composition as described in claim 1 or 2, wherein, The concentration of the water-soluble polymer having an alcoholic hydroxyl group in the side chain in the above-mentioned grinding composition is 0.3 g / L or more.

8. The grinding composition as described in claim 1 or 2, wherein, The concentration of the water-soluble polymer in the above-mentioned grinding composition that does not have alcoholic hydroxyl groups in the side chain is 2 g / L or more and 2.5 g / L or less.

9. The grinding composition as described in claim 1 or 2, wherein, The concentration of the water-soluble polymer having an alcoholic hydroxyl group in the side chain in the above-mentioned grinding composition is 0.3 g / L or more and 0.8 g / L or less.

10. The grinding composition as described in claim 1 or 2, wherein, The weight average molecular weight of the above-mentioned water-soluble polymers having alcoholic hydroxyl groups in their side chains is above 8,000.

11. The grinding composition as described in claim 1 or 2, wherein, The aforementioned water-soluble polymer having alcoholic hydroxyl groups in its side chain is selected from at least one of the group consisting of polyvinyl alcohol, polyvinyl alcohol derivatives, copolymers of vinyl alcohol with other monomers, and derivatives of the aforementioned copolymers.

12. The grinding composition as described in claim 1 or 2, wherein, The water-soluble polymer with alcoholic hydroxyl groups in its side chain is polyvinyl alcohol.

13. The grinding composition as described in claim 1 or 2, wherein, The aforementioned polycarboxylic acids (salts) have hydroxyl groups within their molecules.

14. The grinding composition as described in claim 1 or 2, wherein, The above-mentioned water-soluble polymers that do not have alcoholic hydroxyl groups in their side chains contain polyolefin oxygen groups represented by the following formula (I): [Chemical Formula 1] In the above formula (I), X is an integer of 2 or more, and n is an integer of 2 or more.

15. The grinding composition as described in claim 1 or 2, wherein, The water-soluble polymers that do not have alcoholic hydroxyl groups in their side chains are selected from at least one of the group consisting of polyethylene glycol, polypropylene glycol, polybutanediol, polypentanediol, polyhexanediol, polyheptanediol, polyoctanediol, nonanediol, and polydecanediol.

16. The grinding composition as described in claim 1 or 2, wherein, The weight average molecular weight of the above-mentioned water-soluble polymers that do not have alcoholic hydroxyl groups in their side chains is less than 1,000.

17. The grinding composition as described in claim 1 or 2, wherein, The water-soluble polymer without alcoholic hydroxyl groups in its side chain is polypropylene glycol; the water-soluble polymer with alcoholic hydroxyl groups in its side chain is at least one selected from the group consisting of polyvinyl alcohol and sulfonic acid-modified polyvinyl alcohol; the polycarboxylic acid (salt) includes a salt of a polycarboxylic acid; the salt of the polycarboxylic acid is a salt of citric acid; the oxidant is hydrogen peroxide; and the pH of the grinding composition is 1 or higher and 4 or lower.

18. The polishing composition as claimed in claim 1 or 2, for polishing a polishing object containing a germanium-containing material and a silicon-containing compound other than a germanium-containing material.

19. A grinding method for grinding an object to be ground using a grinding composition as described in any one of claims 1 to 18.

20. The grinding method as described in claim 19, wherein, The objects to be ground include germanium-containing materials and silicon-containing compounds other than germanium-containing materials.

21. The grinding method as described in claim 19, wherein, The objects to be ground include germanium silicon, silicon oxide, and polycrystalline silicon.

22. A method for manufacturing a polished substrate, comprising polishing the substrate, which is the object to be polished, by means of any one of claims 19 to 21.

23. A method for manufacturing a polished substrate as described in claim 22, wherein, The aforementioned substrate contains germanium-containing materials and silicon-containing compounds other than germanium-containing materials.