Aqueous composition containing inorganic particles

Abstract

[Problem] Provided is a composition (slurry) which contains inorganic particles and water and in which sedimentation of the inorganic particles is suppressed. [Solution] This composition comprises inorganic particles, a copolymer (P) obtained by living polymerization, and water, and is characterized in that the copolymer (P) contains a structural unit (a-1) having a structure represented by formula (1) in a side chain and a structural unit (b-1) having an azole structure in a side chain.　(1): *-R13-(OR12)m1-OR11 [In formula (1), R11 represents a hydrogen atom or an alkyl group having 1-3 carbon atoms. R12 represents an alkylene group having 1-3 carbon atoms. R13 represents an alkylene group having 1-3 carbon atoms. m1 represents an integer of 0-30. When m1 is 2 or more, a plurality of the R12s may be the same as or different from each other. * represents a bond. ]

Description

Aqueous composition containing inorganic particles

[0001] The present invention relates to a composition containing inorganic particles and water, and more particularly to a technique for reducing the settling velocity of the inorganic particles.

[0002] In various technological fields, polishing compositions (slurries) containing inorganic particles (abrasive grains) and water are used to polish the surface of components. For example, as a technique for smoothing wafers before the formation of semiconductor devices using silicon wafers as substrates, polishing compositions are used in a polishing process called chemical mechanical polishing (CMP). As abrasive grains, inorganic particles such as cerium oxide (ceria), cerium hydroxide, aluminum oxide (alumina), zirconium oxide (zirconia), titanium dioxide (titania), silicon dioxide (silica), and silicon carbide are used (see, for example, Patent Document 1 (paragraph 0034) and Patent Document 2 (paragraph 0015)), and composite particles in which inorganic particles are attached to the surface of organic particles (see, for example, Patent Document 3 (paragraphs 0033-0035)).

[0003] In polishing compositions for CMP (Computer Polishing), water-soluble polymers such as polyalkylene glycols and polyvinylpyrrolidone (see, for example, Patent Document 4 (paragraphs 0024-0026)) are used to stabilize the dispersion of abrasive grains. Among water-soluble polymers, nitrogen-containing water-soluble polymers function as wetting agents, exhibiting a stress-relieving effect by adsorbing onto the surface of abrasive grains and the workpiece, thereby reducing damage to the workpiece caused by abrasive grains and foreign matter. They can also be expected to impart hydrophilicity to the surface of the workpiece, preventing the adhesion of abrasive grains and foreign matter. As a result, a higher degree of smoothing of the workpiece surface is possible compared to when nitrogen-containing water-soluble polymers are not added.

[0004] Japanese Patent Publication No. 2019-196467, Japanese Patent Publication No. 2023-147153, Japanese Patent Publication No. 2012-135866, Japanese Patent Publication No. 2007-242839

[0005] Because the inorganic particles used in abrasives have a high specific gravity, the settling rate of the abrasive particles in the polishing composition is fast. In other words, if the polishing composition is left standing, the abrasive particles tend to settle. As a result, the concentration of abrasive particles in the polishing composition is unstable, and re-stirring is required before use to achieve the desired polishing properties, which poses practical problems. In addition, there was a problem of abrasive particles settling and accumulating in the polishing machine and piping during the polishing process.

[0006] This invention has been made in view of the above circumstances, and aims to provide a composition (slurry) containing inorganic particles and water in which the settling of inorganic particles is suppressed.

[0007] The present invention, which has been able to solve the above problems, is a composition containing inorganic particles, a copolymer (P) obtained by living polymerization, and water, wherein the copolymer (P) contains a structural unit (a-1) having a structure represented by formula (1) in its side chain and a structural unit (b-1) having an azole structure in its side chain. *-R 13 - ( OR 12 ) m1 -OR 11 (1) [In equation (1), R 11 R represents a hydrogen atom or an alkyl group with 1 to 3 carbon atoms. 12 R represents an alkylene group with 1 to 3 carbon atoms. 13 R represents an alkylene group with 1 to 3 carbon atoms. m1 is an integer from 0 to 30. If m1 is 2 or greater, there are multiple R groups. 12 These may be the same or different. * represents a combination.

[0008] According to the present invention, a composition containing inorganic particles and water is obtained in which the settling of the inorganic particles is suppressed.

[0009] <Definitions> In this specification, "(meth)acrylic" means "at least one of acrylic and methacrylic." "(meth)acrylate" means "at least one of acrylate and methacrylate," and is also an ester compound in which the hydrogen atoms of the carboxyl group of (meth)acrylic acid are replaced with organic groups. "(meth)acrylic monomer" means "a monomer having a (meth)acryloyl group in its molecule," and also includes "(meth)acrylate." "Vinyl monomer" means "a monomer having a radically polymerizable carbon-carbon double bond in its molecule," and also includes "(meth)acrylate" and "(meth)acrylic monomer."

[0010] In this specification, "structural unit derived from (meth)acrylate" means "a structural unit in which the radically polymerizable carbon-carbon double bond of (meth)acrylate polymerizes to form a carbon-carbon single bond." "Structural unit derived from (meth)acrylic monomer" means "a structural unit in which the radically polymerizable carbon-carbon double bond of (meth)acrylic monomer polymerizes to form a carbon-carbon single bond." "Structural unit derived from vinyl monomer" means "a structural unit in which the radically polymerizable carbon-carbon double bond of vinyl monomer polymerizes to form a carbon-carbon single bond."

[0011] In this specification, "X to Y" (where X and Y are any numbers) means "greater than or equal to X and less than or equal to Y". Furthermore, "greater than or equal to X" (where X is any number) also includes the meaning of "X or greater than X", and "less than or equal to Y" (where Y is any number) also includes the meaning of "Y or less than Y". In addition, "X and / or Y (where X and Y are any combination)" means "at least one of X and Y", and has three possible meanings: "X only", "Y only", and "X and Y".

[0012] <Composition> The composition of the present invention contains inorganic particles, a copolymer (P) obtained by living polymerization, and water.

[0013] [Copolymer Obtained by Living Polymerization] The copolymer (P) obtained by the living polymerization (hereinafter referred to as "copolymer (P)") is a copolymer obtained by living polymerization, and has a structural unit (a-1) having a structure represented by the formula (1) in the side chain and a structural unit (b-1) having an azole structure in the side chain. *-R 13 -(OR 12 ) m1 -OR 11 (1) [In the formula (1), R 11 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R 12 represents an alkylene group having 1 to 3 carbon atoms. R 13 represents an alkylene group having 1 to 3 carbon atoms. m1 represents an integer of 0 to 30. When m1 is 2 or more, a plurality of R 12 may be the same or different from each other. * represents a bond.]

[0014] The reason why the copolymer (P) can suppress the precipitation of inorganic particles is not necessarily clear, but it is considered as follows. The copolymer (P) is presumed to have improved adsorptivity to inorganic particles due to having an azole structure in the side chain, and improved affinity to water due to having a group represented by the formula (1). Furthermore, since the copolymer (P) is a copolymer obtained by living polymerization, in the reaction product, the content of the copolymer in which the adsorption sites to inorganic particles and the sites having high affinity to water are evenly arranged is high, and it is presumed that it has an excellent sedimentation suppression effect even with a small molecular weight.

[0015] (Composition of Copolymer) The mass ratio ((a-1) / (b-1)) of the structural unit (a-1) and the structural unit (b-1) in the copolymer (P) is preferably 0.5 or more, more preferably 1.0 or more, still more preferably 1.5 or more, preferably 5.0 or less, more preferably 4.5 or less, still more preferably 4.0 or less. If the mass ratio ((a-1) / (b-1)) is within the above range, the sedimentation suppression effect of inorganic particles is further improved.

[0016] The content of the structural unit (a-1) is preferably 30% by mass or more, more preferably 40% by mass or more, even more preferably 50% by mass or more, preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 75% by mass or less, in 100% by mass of the copolymer (P). If the content of the structural unit (a-1) is within the above range, the effect of suppressing the settling of inorganic particles is further improved.

[0017] The content of the structural unit (b-1) is preferably 9% by mass or more, more preferably 12% by mass or more, even more preferably 15% by mass or more, preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less, in 100% by mass of the copolymer (P). If the content of the structural unit (b-1) is within the above range, the effect of suppressing the settling of inorganic particles is further improved.

[0018] The total content of structural unit (a-1) and structural unit (b-1) ((a-1) + (b-1)) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, preferably 100% by mass or less, and more preferably 98% by mass or less, in 100% by mass of the copolymer (P). If the total content ((a-1) + (b-1)) is within the above range, the effect of suppressing the settling of inorganic particles is further improved.

[0019] (Structural Unit (a-1)) The copolymer (P) contains structural unit (a-1) having a group represented by formula (1). Introducing structural unit (a-1) into the copolymer (P) improves its affinity for water. One type of structural unit (a-1) may be used alone, or two or more types may be used in combination. *-R 13 - ( OR 12 ) m1 -OR 11 (1) [In equation (1), R 11 R represents a hydrogen atom or an alkyl group with 1 to 3 carbon atoms. 12 R represents an alkylene group with 1 to 3 carbon atoms. 13 R represents an alkylene group with 1 to 3 carbon atoms. m1 is an integer from 0 to 30. If m1 is 2 or greater, there are multiple R groups. 12These may be the same or different. * represents a combination.

[0020] The aforementioned R 11 The alkyl group having 1 to 3 carbon atoms, as shown, may be linear or branched, but linear is preferred. 11 Specific examples of alkyl groups having 1 to 3 carbon atoms as shown include methyl group, ethyl group, n-propyl group, isopropyl group, etc. 12 and R 13 The alkylene group having 1 to 3 carbon atoms, as indicated by R, may be linear or branched, but linear is preferred. 12 and R 13 Specific examples of alkylene groups with 1 to 3 carbon atoms, as shown by R, include methylene group, ethylene group, trimethylene group, propane-1,2-diyl group, etc. 12 and R 13 The ethylene group or trimethylene group is preferred. The m1 is preferably 1 or more, more preferably 5 or more, preferably 20 or less, and more preferably 15 or less.

[0021] In the structural unit (a-1), the group represented by formula (1) is introduced into the side chain portion. The group represented by formula (1) may be directly bonded to the carbon atoms constituting the main chain, or it may be bonded via other atoms. Preferably, the group represented by formula (1) is bonded to the carbon atoms constituting the main chain via an ester bond (-CO-O-) or an amide bond (-CO-NH-). The bonding direction of the amide group and the ester group is not particularly limited.

[0022] Examples of monomers that form the structural unit (a-1) include compounds having one carbon-carbon double bond and one group represented by formula (1) in the molecule.

[0023] The structural unit (a-1) is preferably a structural unit represented by formula (2).

[0024] [In equation (2), R 21 R represents a hydrogen atom or an alkyl group with 1 to 3 carbon atoms. 22R represents an alkylene group with 1 to 3 carbon atoms. 23 R represents an alkylene group with 1 to 3 carbon atoms. 24 R represents a hydrogen atom or a methyl group. m2 is an integer from 0 to 30. Note that if m2 is 2 or more, there are multiple R 22 These may be the same or different.

[0025] The aforementioned R 21 The alkyl group having 1 to 3 carbon atoms, as shown, may be linear or branched, but linear is preferred. 21 Specific examples of alkyl groups having 1 to 3 carbon atoms as shown include methyl group, ethyl group, n-propyl group, isopropyl group, etc. 22 and R 23 The alkylene group having 1 to 3 carbon atoms, as indicated by R, may be linear or branched, but linear is preferred. 22 and R 23 Specific examples of alkylene groups having 1 to 3 carbon atoms as shown include methylene group, ethylene group, trimethylene group, propane-1,2-diyl group, etc. 22 and R 23 The group is preferably an ethylene group or a trimethylene group. The m2 is preferably 1 or more, more preferably 5 or more, preferably 20 or less, and more preferably 15 or less.

[0026] Examples of monomers constituting the structural unit represented by formula (2) include (meth)acrylates having alkoxypolyalkylene glycol groups, (meth)acrylates having hydroxypolyalkylene glycol groups, (meth)acrylates having hydroxyalkyl groups, and (meth)acrylates having alkoxyalkyl groups.

[0027] Examples of (meth)acrylates having alkoxy polyalkylene glycol groups include polyethylene glycol (degree of polymerization = 2-30) methyl ether (meth)acrylate, polyethylene glycol (degree of polymerization = 2-30) ethyl ether (meth)acrylate, polyethylene glycol (degree of polymerization = 2-30) propyl ether (meth)acrylate, polyethylene glycol (degree of polymerization = 2-30) mono(meth)acrylate, polypropylene glycol (degree of polymerization = 2-30) methyl ether (meth)acrylate, polypropylene glycol (degree of polymerization = 2-30) ethyl ether (meth)acrylate, polypropylene glycol (degree of polymerization = 2-30) propyl ether (meth)acrylate, and polypropylene glycol (degree of polymerization = 2-30) mono(meth)acrylate. Examples of (meth)acrylates having hydroxy polyalkylene glycol groups include terminal hydroxyl group polyethylene glycol (degree of polymerization = 2-10) mono(meth)acrylate and terminal hydroxyl group polypropylene glycol (degree of polymerization = 2-10) mono(meth)acrylate. Examples of (meth)acrylates having a hydroxyalkyl group include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate. Examples of (meth)acrylates having an alkoxyalkyl group include methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate.

[0028] (Structural Unit (b-1)) The copolymer (P) contains structural unit (b-1) having an azol structure in its side chain. Introducing structural unit (b-1) into the copolymer (P) improves its adsorption to inorganic particles. One type of structural unit (b-1) may be used alone, or two or more types may be used in combination.

[0029] The aforementioned azole structure refers to a heterogeneous five-membered ring structure containing one or more nitrogen atoms, and also includes structures substituted with heterogeneous atoms other than nitrogen. Examples of heterogeneous atoms other than nitrogen include oxygen (O) and sulfur (S). Examples of azole structures include pyrrole structures, imidazole structures, pyrazole structures, isothiazole structures, isoxazole structures, and furazan structures. However, in this invention, five-membered ring lactam structures are not included in the definition of azole structures.

[0030] In the structural unit (b-1) described above, the azole structure is introduced into the side chain portion. The azole structure may be directly bonded to the carbon atoms constituting the main chain, or it may be bonded via other atoms. When the azole structure is bonded via other atoms, it is preferable that it is bonded to the carbon atoms constituting the main chain via an ester bond (-CO-O-) or an amide bond (-CO-NH-). The bonding direction of the amide group and ester group is not particularly limited.

[0031] Examples of monomers that form the structural unit (b-1) include compounds having one carbon-carbon double bond and one azole structure in the molecule. Preferably, the nitrogen atom constituting the ring of the azole structure is directly bonded to the carbon atom constituting the vinyl group (CH2=C-).

[0032] The structural unit (b-1) is preferably a structural unit represented by formula (3).

[0033] [In equation (3), R 31 R represents an alkyl group with 1 to 4 carbon atoms. m3 is an integer from 0 to 3. Note that if m3 is 2 or more, there are multiple R groups. 31 These may be the same or different.

[0034] The aforementioned R 31 The alkyl group having 1 to 4 carbon atoms, as shown, may be linear or branched, but linear is preferred. 31Specific examples of alkyl groups having 1 to 4 carbon atoms as shown include methyl group, ethyl group, n-propyl group, isopropyl group, and butyl group. The aforementioned m3 is 0 or more and 3 or less, preferably 0 or 1.

[0035] Examples of monomers constituting the structural unit represented by formula (3) include 1-vinylimidazole, 1-vinyl-2-methylimidazole, 1-vinyl-2,4-dimethylimidazole, 2-vinylimidazole, 1-methyl-2-vinylimidazole, 1-methyl-5-vinylimidazole, 1-ethyl-5-vinylimidazole, 1-propyl-5-vinylimidazole, and 1-butyl-5-vinylimidazole.

[0036] (Other structural units) The copolymer (P) may contain other structural units other than structural unit (a-1) and structural unit (b-1) to an extent that does not impair the effects of the present invention.

[0037] Other structural units include structural units derived from (meth)acrylic monomers and structural units derived from vinyl monomers other than (meth)acrylic monomers. These other structural units may be used individually or in combination of two or more types.

[0038] Examples of (meth)acrylic monomers that form structural units derived from the (meth)acrylic monomer include (meth)acrylic monomers having a chain alkyl group, (meth)acrylic monomers having a cyclic alkyl group, (meth)acrylic monomers having an aryl group, (meth)acrylic monomers having a lactone-modified hydroxyl group, (meth)acrylic monomers having an oxygen-containing heterocyclic group, (meth)acrylic monomers having an amino group, (meth)acrylic monomers having an amide group, (meth)acrylic monomers having an acidic group, and (meth)acrylic monomers having a cyano group.

[0039] Examples of the (meth)acrylic monomer having a linear alkyl group include (meth)acrylate having a linear alkyl group and (meth)acrylate having a branched alkyl group. The linear alkyl group of the (meth)acrylate having a linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms. Specific examples of the (meth)acrylate having a linear alkyl group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-lauryl (meth)acrylate, and n-stearyl (meth)acrylate. The branched alkyl group of the (meth)acrylate having a branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 10 carbon atoms. Specific examples of (meth)acrylates having the branched alkyl group include isopropyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate, and isodecyl (meth)acrylate.

[0040] Examples of the (meth)acrylic monomer having a cyclic alkyl group include (meth)acrylates having a monocyclic cyclic alkyl group and (meth)acrylates having a cyclic alkyl group having a crosslinked ring structure. The monocyclic cyclic alkyl group of the (meth)acrylate having a monocyclic cyclic alkyl group preferably has 6 to 12 carbon atoms. Specific examples of the (meth)acrylate having a monocyclic cyclic alkyl group include cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, and cyclododecyl (meth)acrylate. The cyclic alkyl group having a crosslinked ring structure of the (meth)acrylate having a cyclic alkyl group having a crosslinked ring structure preferably has 6 to 12 carbon atoms. Specific examples of (meth)acrylates having a cyclic alkyl group with a cross-linking ring structure include isobornyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, and 2-ethyl-2-adamantyl (meth)acrylate.

[0041] The aryl group of the (meth)acrylic monomer having an aryl group preferably has 6 to 12 carbon atoms and may have a chain-like portion such as an alkylaryl group, aralkyl group, or aryloxyalkyl group. Examples of the (meth)acrylic monomer having an aryl group include (meth)acrylate having an aryl group, and specific examples include benzyl (meth)acrylate, phenyl (meth)acrylate, and phenoxyethyl (meth)acrylate.

[0042] Examples of the lactone-modified hydroxyl group-containing (meth)acrylic monomer include (meth)acrylates having lactone-modified hydroxyl groups. Examples of the lactone-modified hydroxyl group-containing (meth)acrylate include those obtained by adding a lactone to a (meth)acrylate having a hydroxyalkyl group, with caprolactone being preferred. The amount of caprolactone added is preferably 1 mol to 20 mol, more preferably 1 mol to 10 mol. Specific examples of the lactone-modified hydroxyl group-containing (meth)acrylate include a 1 mol adduct of caprolactone to 2-hydroxyethyl (meth)acrylate, a 2 mol adduct of caprolactone to 2-hydroxyethyl (meth)acrylate, a 3 mol adduct of caprolactone to 2-hydroxyethyl (meth)acrylate, a 4 mol adduct of caprolactone to 2-hydroxyethyl (meth)acrylate, a 5 mol adduct of caprolactone to 2-hydroxyethyl (meth)acrylate, and a 10 mol adduct of caprolactone to 2-hydroxyethyl (meth)acrylate.

[0043] The oxygen-containing heterocyclic group of the (meth)acrylic monomer having the oxygen-containing heterocyclic group is preferably a 4-membered to 6-membered ring. Specific examples of the (meth)acrylic monomer having the oxygen-containing heterocyclic group include glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, cyclic trimethylolpropaneformal (meth)acrylate, and 2-[(2-tetrahydropyranyl)oxy]ethyl (meth)acrylate.

[0044] The amino group in the (meth)acre monomer having the amino group includes, in addition to the common amino group (-NH2), -NHR, in which H is substituted with a hydrocarbon group. a , -NR a R b (R a , R b Each of these independently represents a chain-like or cyclic hydrocarbon group. Also, R a and R bThese groups may be bonded to each other to form a cyclic structure. This also includes substituted amino groups represented by ).Specific examples of (meth)acryl monomers having amino groups include dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, dimethylaminobutyl (meth)acrylate, diethylaminoethyl (meth)acrylate, diethylaminopropyl (meth)acrylate, diethylaminobutyl (meth)acrylate, ethylaminoethyl (meth)acrylate, ethylaminopropyl (meth)acrylate, ethylaminobutyl (meth)acrylate, propylaminoethyl (meth)acrylate, propylaminopropyl (meth)acrylate, propylaminobutyl (meth)acrylate, dimethylaminopropyl (meth)acrylamide, and the like.

[0045] Examples of (meth)acrylic monomers having the amide group include N,N-dimethyl(meth)acrylamide and 4-(meth)acryloylmorpholin.

[0046] Examples of acidic groups found in the (meth)acre monomer having the aforementioned acidic group include a carboxyl group (-COOH), a sulfonic acid group (-SO3H), a phosphate group (-OPO3H2), a phosphonic acid group (-PO3H2), and a phosphinic acid group (-PO2H2). Specific examples of the (meth)acrylic monomer having the acidic group include (meth)acrylic acid; (meth)acrylates having a carboxyl group such as 2-(meth)acryloyloxy)ethyl hydrogen succinate, 2-(meth)acryloyloxy)ethyl hydrogen hexahydrophthalate, 2-(meth)acryloyloxy)ethyl hydrogen phthalate, caprolactone adduct of (meth)acrylic acid, 2-carboxyethyl (meth)acrylic acid, 2-carboxypropyl (meth)acrylic acid, 3-carboxypropyl (meth)acrylic acid, 4-carboxybutyl (meth)acrylic acid, and 5-carboxypentyl (meth)acrylic acid; (meth)acrylates having a phosphate group such as 2-(phosphonooxy)ethyl (meth)acrylic acid; and (meth)acrylates having a sulfonic acid group such as 2-sulfoethyl (meth)acrylic acid and 2-(meth)acrylamido-2-methylpropanesulfone. Preferably, (meth)acrylic acid and (meth)acrylates having a carboxyl group are used.

[0047] Examples of (meth)acrylic monomers having a cyano group include (meth)acrylonitrile, cyanomethyl (meth)acrylate, cyanoethyl (meth)acrylate, and 4-cyanostyrene.

[0048] Examples of vinyl monomers that form structural units derived from vinyl monomers other than the (meth)acrylic monomers mentioned above include α-olefins, styrene monomers, vinyl monomers having a hydroxyl group, vinyl monomers having a cyano group, vinyl amides, vinyl carboxylates, dienes, and the like. Examples of the α-olefins include 1-hexene, 1-octene, and 1-decene. Examples of the styrene monomers include substituted or unsubstituted styrene. Examples of substituents that may be substituted on styrene include alkyl groups, aryl groups, alkoxy groups, and aryloxy groups. Furthermore, styrene monomers also include fused ring compounds in which two or more benzene rings are fused. Specific examples of the styrene monomers include styrene, α-methylstyrene, 4-methylstyrene, 2-methylstyrene, 3-methylstyrene, 2,4-dimethylstyrene, 4-methoxystyrene, 4-phenylstyrene, 2-hydroxymethylstyrene, and 1-vinylnaphthalene. Examples of vinyl monomers having a hydroxyl group include 4-vinylphenol and 4-hydroxybutyl vinyl ether. Examples of vinyl monomers having a cyano group include 4-cyano-α-methylstyrene. Examples of vinylamides include N-vinylformamide, N-vinylacetamide, and N-vinyl-ε-caprolactam. Examples of vinyl carboxylates include vinyl acetate, vinyl pivalate, and vinyl benzoate. Examples of dienes include butadiene, isoprene, 4-methyl-1,4-hexadiene, and 7-methyl-1,6-octadiene.

[0049] The other structural units are preferably structural units derived from one or more vinyl monomers selected from the group consisting of (meth)acrylic monomers having a chain alkyl group, (meth)acrylic monomers having a cyclic alkyl group, (meth)acrylic monomers having an aryl group, (meth)acrylic monomers having a hydroxyalkyl group, (meth)acrylic monomers having a lactone-modified hydroxyl group, (meth)acrylic monomers having an alkoxyalkyl group, and (meth)acrylic monomers having an acidic group.

[0050] If the copolymer (P) contains the other structural units, the content of the other structural units is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, preferably 30% by mass or less, and more preferably 25% by mass or less, based on 100% by mass of the copolymer (P).

[0051] (Physical properties of the copolymer) The number-average molecular weight (Mn) of the copolymer (P) is preferably 4,000 or more, more preferably 5,000 or more, even more preferably 6,000 or more, preferably 30,000 or less, more preferably 20,000 or less, and even more preferably 15,000 or less. If the number-average molecular weight (Mn) is within the above range, the effect of suppressing the sedimentation of inorganic particles is better while suppressing the thickening of the composition. The number-average molecular weight of the copolymer (P) is measured by gel permeation chromatography (hereinafter referred to as "GPC").

[0052] The molecular weight distribution (Mw / Mn) of the copolymer (P) is preferably 4.0 or less, more preferably 3.9 or less, and even more preferably 3.8 or less. A molecular weight distribution (Mw / Mn) of 4.0 or less provides a better effect in suppressing the sedimentation of inorganic particles. The molecular weight distribution is determined by (weight-average molecular weight (Mw) of copolymer (P)) / (number-average molecular weight (Mn) of copolymer (P)). A smaller molecular weight distribution value indicates a narrower molecular weight distribution and a copolymer with more uniform molecular weights, with the narrowest molecular weight distribution occurring when the value is 1.0. In other words, the lower limit of the molecular weight distribution is 1.0.

[0053] (Structure of the copolymer) The copolymer (P) may be a random copolymer, a block copolymer, or a graft copolymer. The copolymer (P) has structural units (a-1) that have a high affinity for water and structural units (b-1) that have a high affinity for inorganic particles. Therefore, it is thought that the copolymer (P) is adsorbed around the inorganic particles by the action of structural units (b-1), and the settling of inorganic particles in water can be suppressed. For this reason, even if it is a random copolymer, the settling of inorganic particles can be suppressed.

[0054] The copolymer (P) is preferably a block copolymer, and more preferably a block copolymer having an A block and a B block, wherein the A block has structural unit (a-1) and the B block has structural unit (b-1). It is believed that by forming a block copolymer, the structural units of the A block and the B block are localized, allowing them to efficiently and suitably interact with inorganic particles and water, thereby further improving dispersibility.

[0055] The structure of the block copolymer is preferably a linear block copolymer. Furthermore, the linear block copolymer may have any structure (arrangement), but from the viewpoint of the physical properties of the linear block copolymer or the composition, when block A is denoted as A and block B as B, (A - B) m Type, (A-B) m - Type A and (B-A) m It is preferable that the copolymer has at least one structure selected from the group consisting of -B type (where m is an integer of 1 or more, for example, an integer from 1 to 3). Among these, an A-B type diblock copolymer is preferred from the viewpoint of ease of handling during processing. The block copolymer may have other blocks besides the A block and the B block.

[0056] The mass ratio of block A to block B in the block copolymer (block A / block B) is preferably 50 / 50 or more, more preferably 60 / 40 or more, even more preferably 65 / 45 or more, preferably 90 / 10 or less, more preferably 85 / 15 or less, and even more preferably 80 / 20 or less. A mass ratio (block A / block B) of 50 / 50 or more results in better affinity with water, and a mass ratio of 90 / 10 or less results in better adsorption to inorganic particles.

[0057] (Block A) Block A has structural units (a-1). The content of structural units (a-1) is preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, preferably 100% by mass or less, more preferably 98% by mass or less, and even more preferably 95% by mass or less, in 100% by mass of Block A. If the content of structural units (a-1) is within the above range, the effect of suppressing the settling of inorganic particles is further improved.

[0058] Block A may contain structural units other than structural unit (a-1) as described above. Block A may also contain structural units derived from (meth)acrylic monomers having a chain-like alkyl group. When Block A contains structural units derived from (meth)acrylic monomers having a chain-like alkyl group, the content is preferably 2% by mass or more, more preferably 5% by mass or more, preferably 70% by mass or less, more preferably 50% by mass or less, and even more preferably 30% by mass or less, based on 100% by mass of Block A. If the content of structural units derived from (meth)acrylic monomers having a chain-like alkyl group is 2% by mass or more, the affinity between Block A and the solvent will be better, and if it is 70% by mass or less, the dispersibility of inorganic particles will be better. Furthermore, the total content of structural unit (a-1) and structural units derived from (meth)acrylic monomers having a chain-like alkyl group is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 95% by mass or more, based on 100% by mass of Block A.

[0059] It is preferable that block A substantially does not contain structural unit (b-1). In other words, it is preferable that the monomers constituting block A do not contain monomers that form structural unit (b-1) which has high adsorption properties to the inorganic particles. If structural unit (b-1) is not present in block A, the inorganic particles are more easily adsorbed onto block B, and the effect of suppressing the settling of inorganic particles is further improved. The content of structural unit (b-1) in 100% by mass of structural units constituting block A is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less.

[0060] If the A block contains two or more structural units, the various structural units contained in the A block may be contained in the A block in any manner, such as random copolymerization or block copolymerization, and it is preferable that they be contained in a manner of random copolymerization from the viewpoint of uniformity. For example, the A block may be formed by a copolymer of structural units consisting of block a1 and structural units consisting of block a2.

[0061] (Block B) The Block B has structural units (b-1). The content of structural units (b-1) is preferably 50% by mass or more, more preferably 65% ​​by mass or more, even more preferably 80% by mass or more, preferably 100% by mass or less, and more preferably 98% by mass or less, in 100% by mass of the Block B. If the content of structural units (b-1) is 50% by mass or more, the adsorption of Block B to inorganic particles is further improved, and if it is 100% by mass or less, the dispersibility of inorganic particles is further improved.

[0062] The B block may contain structural units other than structural unit (b-1) as described above. The B block may also contain structural units derived from (meth)acrylic monomers having a cyclic alkyl group. When the B block contains structural units derived from (meth)acrylic monomers having a cyclic alkyl group, the content is preferably 2% by mass or more, more preferably 5% by mass or more, preferably 50% by mass or less, more preferably 35% by mass or less, and even more preferably 20% by mass or less, based on 100% by mass of the B block. If the content of structural units derived from (meth)acrylic monomers having a cyclic alkyl group is 2% by mass or more, the dispersibility of inorganic particles will be better, and if it is 50% by mass or less, the adsorption of the B block to inorganic particles will be better. Furthermore, the total content of structural unit (b-1) and structural units derived from (meth)acrylic monomers having a cyclic alkyl group is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 95% by mass or more, based on 100% by mass of the B block.

[0063] It is preferable that the B block substantially does not contain structural unit (a-1). In other words, it is preferable that the monomers constituting the B block do not contain monomers that form structural unit (a-1) which has a high affinity for water. If structural unit (a-1) is not present in the B block, inorganic particles are more easily adsorbed onto the B block, and the effect of suppressing the settling of inorganic particles is further improved. The content of structural unit (a-1) in 100% by mass of structural units constituting the B block is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less.

[0064] If the B block contains two or more structural units, the various structural units contained in the B block may be contained in the B block in any manner, such as random copolymerization or block copolymerization, and it is preferable that they be contained in a manner of random copolymerization from the viewpoint of uniformity. For example, the B block may be formed by a copolymer of structural units consisting of block b1 and structural units consisting of block b2.

[0065] (Method for producing copolymers) The copolymer (P) is obtained by living polymerization of vinyl monomers. In living polymerization, among the four elementary reactions in chain polymerization (initiation, growth, termination, and chain transfer), side reactions such as termination and chain transfer reactions are substantially absent, and the vinyl monomer reacts and polymer chains grow without deactivation of the reaction sites (polymerization growth ends). Therefore, it is easy to produce copolymers with a narrow molecular weight distribution and a uniform composition. Living polymerization includes living radical polymerization, living anionic polymerization, and living cationic polymerization. Among these, living radical polymerization is preferred from the viewpoint of ease of polymerization. Furthermore, living radical polymerization is also preferred because it allows for precise control of molecular weight distribution and easy production of polymers with a uniform composition while maintaining the ease and versatility of free radical polymerization.

[0066] By using copolymer (P) obtained by living polymerization, the content of copolymers in the reaction product, in which adsorbent sites for inorganic particles and sites with high affinity for water are evenly distributed, is increased, and it is thought that an excellent sedimentation suppression effect can be obtained even with a small molecular weight.

[0067] Living radical polymerization includes methods that utilize compounds capable of generating nitroxide radicals, depending on the method used to stabilize the polymerization growth ends (nitroxide method; NMP method); methods that use metal complexes such as copper and ruthenium, with halogenated compounds as polymerization initiators, and polymerize them in a living manner (ATRP method); methods that use dithiocarboxylic acid esters or xantate compounds (RAFT method); methods that use organotellurium compounds (TERP method); methods that use organiodine compounds (ITP method); and methods that use iodine compounds as polymerization initiators and organic compounds such as phosphorus compounds, nitrogen compounds, oxygen compounds, or hydrocarbons as catalysts (reversible transfer catalytic polymerization; RTCP method, reversible catalyst-mediated polymerization; RCMP method). Among these methods, the TERP method is preferred from the viewpoint of the diversity of monomers that can be used, molecular weight control in the polymer range, uniform composition, and coloration.

[0068] The TERP method is a method for polymerizing radical polymerizable compounds (vinyl monomers) using an organic tellurium compound as a chain transfer agent, and is described, for example, in International Publication Nos. 2004 / 14848, 2004 / 14962, 2004 / 072126, 2004 / 096870, and 2020 / 116144. Specific polymerization methods of the TERP method include the following (a) to (d): (a) A method of polymerizing vinyl monomer using an organic tellurium compound represented by formula (T1). (b) A method of polymerizing vinyl monomer using a mixture of an organic tellurium compound represented by formula (T1) and an azo polymerization initiator. (c) A method of polymerizing vinyl monomer using a mixture of an organic tellurium compound represented by formula (T1) and an organic diterlide compound represented by formula (T2). (d) A method for polymerizing vinyl monomer using a mixture of an organic tellurium compound represented by formula (T1), an azo polymerization initiator, and an organic diterlide compound represented by formula (T2).

[0069] R t1 -Te-CR t2 R t3 R t4 (T1) Rt1 -Te-Te-R t1 (T2) [In equations (T1) and (T2), R t1 R represents an alkyl group, aryl group, or aromatic heterocyclic group having 1 to 8 carbon atoms. t2 and R t3 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. t4 This represents an alkyl group, aryl group, substituted aryl group, aromatic heterocyclic group, alkoxy group, acyl group, amide group, oxycarbonyl group, cyano group, allyl group, or propargyl group having 1 to 8 carbon atoms.

[0070] The organic tellurium compounds represented by formula (T1) include, specifically, ethyl = 2-methyl-2-n-butylteranyl propionate, ethyl = 2-n-butylteranyl propionate, (2-hydroxyethyl) = 2-methyl-methylteranyl propionate, and other organic tellurium compounds described in International Publication Nos. 2004 / 14848, 2004 / 14962, 2004 / 072126, 2004 / 096870, and 2020 / 116144.

[0071] Specific examples of the organic diterlide compound represented by formula (T2) include dimethyl diterlide and dibutyl diterlide. The azo polymerization initiator can be any azo polymerization initiator used in normal radical polymerization without particular restrictions, such as 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 1,1'-azobis(1-cyclohexanecarbonitride), dimethyl-2,2'-azobisisobutyrate, 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), and 2,2'-azobis(N-butyl-2-methylpropionamide).

[0072] The polymerization step involves mixing a vinyl monomer, an organic tellurium compound of formula (T1), and, depending on the type of vinyl monomer, an azo polymerization initiator and / or an organic diterlide compound of formula (T2) in a container purged with an inert gas. Examples of inert gases used include nitrogen, argon, and helium. Argon and nitrogen are preferred. The amount of vinyl monomer used in (a), (b), (c), and (d) above may be adjusted as appropriate depending on the desired properties of the copolymer.

[0073] The polymerization reaction can be carried out without a solvent, but it may also be carried out using an aprotic or protic solvent commonly used in radical polymerization, while stirring the mixture. Examples of usable aprotic solvents include acetonitrile, methyl ethyl ketone, anisole, benzene, toluene, propylene glycol monomethyl ether acetate, ethyl acetate, tetrahydrofuran, N,N-dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, acetone, dioxane, chloroform, and carbon tetrachloride. Examples of protic solvents include water, methanol, ethanol, isopropanol, n-butanol, ethyl cellosolve, butyl cellosolve, 1-methoxy-2-propanol, hexafluoroisopropanol, and diacetone alcohol. The solvent may be used alone or in combination of two or more. The amount of solvent used can be adjusted as appropriate; for example, 0.01 ml to 50 ml per 1 g of vinyl monomer is preferred. In addition to the solvent, a surfactant and / or dispersant may also be used in the polymerization reaction. The reaction temperature and reaction time can be adjusted as appropriate depending on the molecular weight or molecular weight distribution of the copolymer obtained, but typically, the reaction is carried out with stirring at 0°C to 150°C for 1 minute to 100 hours. At this time, the reaction is usually carried out at atmospheric pressure, but it may also be carried out under increased or decreased pressure. The polymerization reaction may also be carried out under light irradiation. After the polymerization reaction is complete, the target copolymer can be separated from the reaction mixture by removing the solvent used, residual vinyl monomer, etc., using conventional separation and purification methods.

[0074] The growth ends of the copolymer obtained by the polymerization reaction are derived from the tellurium compound -TeR t1 (In the formula, R t1 The form is the same as described above, and although it is deactivated by handling in air after the polymerization reaction is complete, tellurium atoms may remain. Copolymers with tellurium atoms remaining at the ends may be discolored or have poor thermal stability, so it is preferable to remove the tellurium atoms. Methods for removing tellurium atoms include radical reduction methods; adsorption methods using activated carbon, etc.; and adsorption methods using ion exchange resins, etc. These methods can also be used in combination. The other end of the copolymer obtained by the polymerization reaction (the end opposite to the growth end) is -CR derived from the tellurium compound. t2 R t3 R t4 (In the formula, R t2 , R t3 and R t4 The form is the same as described above. Therefore, the copolymer obtained by the TERP method does not have substituents containing sulfur atoms at the terminals.

[0075] The copolymer (P) is prepared as a copolymer solution before the composition is prepared, which facilitates the dispersion of inorganic particles. The solvent used in the copolymer solution is preferably one that can dissolve the copolymer (P) and does not react with these components. Examples of such solvents include water and aqueous organic solvents, which will be discussed later. The solvent content in the copolymer solution is not particularly limited and can be adjusted as appropriate. The upper limit of the solvent content in the copolymer solution is usually 99% by mass. The lower limit of the solvent content in the copolymer solution is usually 10% by mass, preferably 30% by mass, taking into consideration the viscosity suitable for the production of the composition.

[0076] [Inorganic Particles] Examples of inorganic particles include silica (colloidal silica, fumed silica, precipitated silica, etc.), alumina, ceria, oxides such as chromium oxide, titanium dioxide, zirconium oxide, magnesium oxide, manganese dioxide, zinc oxide, and red iron oxide; nitrides such as silicon nitride and boron nitride; carbides such as silicon carbide and boron carbide; diamond; carbonates such as calcium carbonate and barium carbonate; cerium hydroxide; and modified products thereof. Examples of the modified products include inorganic particles whose surfaces have been modified with silane coupling agents or epoxide compounds.

[0077] The inorganic particles are preferably metal oxides or metal hydroxides, and more preferably silica, alumina, or ceria, from the viewpoint of adsorption of structural units (b-1).

[0078] When the above composition is used for polishing silicon wafers, it is preferable that it contains only silica as inorganic particles. If silica, which consists of the same elements and oxygen atoms as the object to be polished, is used as an abrasive grain, no residue of metals or metalloids other than silicon will be generated after polishing. In addition, ceria has lower hardness than silica and the like, which can suppress the occurrence of defects on the polished surface.

[0079] The BET specific surface area diameter of the primary particles of the inorganic particles is not particularly limited, but is usually 1 nm to 10 μm. When the inorganic particles are used as abrasive grains, the BET specific surface area diameter of the primary particles is preferably 2 nm or more, more preferably 3 nm or more, preferably 7 μm or less, and more preferably 5 μm or less, from the viewpoint of ensuring a high polishing speed. Furthermore, from the viewpoint of suppressing the occurrence of scratches on the surface of the object to be polished, it is preferably 300 nm or less, and more preferably 200 nm or less.

[0080] The density of the inorganic particles at 25°C is preferably 2 g / cm³. 3 The above is preferable, 5 g / cm³. 3 The following is preferable: 8 g / cm³ 3 The following is true: When the density (at 25°C) is within the above range, the effect of the copolymer in suppressing sedimentation of inorganic particles becomes significant.

[0081] [Water] As the water, ion-exchanged water (deionized water), pure water, ultrapure water, distilled water, etc., can be preferably used. When the above composition is used as an abrasive composition, in order to avoid as much as possible the function of other components contained in the water, the purity of the water can be increased by operations such as removal of impurity ions with ion exchange resin, removal of foreign matter with a filter, or distillation.

[0082] (Aqueous Organic Solvent) The above composition may further contain an aqueous organic solvent (an organic solvent miscible with water) depending on the intended use. Examples of aqueous organic solvents include alcohols such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, 1-methoxy-2-propanol, and 1-butoxy-2-propanol; polyhydric alcohols such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, and glycerin; ethers such as tetrahydrofuran, dioxane, ethylene glycol methyl ether, ethylene glycol ethyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, triethylene glycol, monomethyl ether, and monoethyl ether; ketones such as acetone, methyl ethyl ketone, and isobutyl ketone; and amides such as dimethylformaldehyde and dimethylacetamide.

[0083] [Formulation of the composition] The composition is usually prepared as a slurry mixture by mixing each component using a known method such as a homomixer or a high-pressure homogenizer.

[0084] The inorganic particle content in the composition is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 10% by mass or more, and particularly preferably 15% by mass or more, from the viewpoint of achieving a high polishing speed when inorganic particles are used as abrasive grains. Furthermore, from the viewpoint of improving the smoothness of the object to be polished, it is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less.

[0085] Preferably, the particle size of inorganic particles in the composition, as measured at 25°C using a concentrated particle size analyzer (product name: FPAR-1000, manufactured by Otsuka Electronics), is between 1 nm and 10 μm.

[0086] The content of copolymer (P) in the above composition is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, preferably 30 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of inorganic particles. When the content of copolymer (P) is within the above range, the polishing speed is good.

[0087] Preferably, 90% or more by volume of the solvent in the composition is water, and more preferably 95% or more by volume is water. If the composition is an abrasive composition, it is preferable that 99% to 100% by volume of the solvent in the composition is water.

[0088] When the above composition is used as an abrasive composition, the viscosity at 25°C can be appropriately selected depending on the object to be polished and the shear rate during polishing, but is preferably 0.1 mPa·s to 10 mPa·s, and more preferably 0.5 mPa·s to 6 mPa·s.

[0089] The composition may contain other compounding agents in addition to inorganic particles, copolymer (P), and water, depending on the application. In this case, the solid content concentration in the composition (concentration of components other than the solvent) is preferably 0.001% by mass or more, more preferably 0.003% by mass or more, even more preferably 0.005% by mass or more, preferably 0.1% by mass or less, more preferably 0.05% by mass or less, and even more preferably 0.03% by mass or less.

[0090] <Applications> Because the inorganic particles in the composition of the present invention are less likely to settle due to the effect of the copolymer (P), it can be suitably used as an abrasive composition containing inorganic particles with a high specific gravity.

[0091] Furthermore, the polishing composition is useful as a chemical mechanical polishing composition used for surface planarization of insulating layers and / or wiring layers in the manufacturing process of semiconductor devices. For example, by using it as a polishing liquid (chemical mechanical polishing composition) for planarization of oxide films (such as silicon oxide films) during shallow trench separation (STI) fabrication, surface planarization of interlayer insulating films (oxide films), and surface planarization of metal wiring made of copper, copper alloys, aluminum alloys, etc., the occurrence of defects can be reduced, and insulating films and metal wiring with excellent surface smoothness can be obtained. In addition, by incorporating a copolymer (P), the settling of abrasive grains is suppressed, and the dispersibility of abrasive grains in the slurry is also improved. As a result, abrasive grains can contact the entire wafer surface uniformly, and the number of effective abrasive grains increases. Accordingly, the amount of material removed per unit time (polishing rate) can be improved.

[0092] When the above composition is used as an abrasive composition, other compounding agents may be added depending on the shape and material of the object to be polished.

[0093] Other compounding agents used when the above composition is used as a chemical mechanical polishing composition include oxidizing agents for the workpiece, protective film-forming agents for metal surfaces, metal oxide dissolving agents, polymers other than copolymers (P), dispersants, surfactants, preservatives, and fungicides.

[0094] Examples of the oxidizing agent include hydrogen peroxide, nitric acid, potassium periodate, hypochlorous acid, and ozonated water, and two or more of these may be used in combination. The amount of the oxidizing agent is preferably 0.003 mol to 0.7 mol, more preferably 0.03 mol to 0.5 mol, and even more preferably 0.2 mol to 0.3 mol per 100 g of the chemical mechanical polishing composition. By having the amount of the oxidizing agent within the above range, a high polishing speed is maintained and the polished surface becomes smooth.

[0095] Examples of the protective film-forming agent include nitrogen-containing compounds (excluding copolymers (P), such as ammonia, alkylamines, amino acids, imines, azoles and their salts), mercaptans, glucose, cellulose, etc. Specific examples include ammonia; alkylamines such as dimethylamine, trimethylamine, triethylamine, propylenediamine, ethylenediaminetetraacetic acid (EDTA), sodium diethyldithiocarbamate, and chitosan; glycine, L-alanine, β-alanine, L-2-aminobutyric acid, L-norvaline, L-valine, L-leucine, L-norleucine, L-isoleucine, L-alloisoleucine, and L-pheni L-alanine, L-proline, sarcosine, L-ornithine, L-lysine, taurine, L-serine, L-threonine, L-alotreonine, L-homoserine, L-tyrosine, 3,5-diiodo-L-tyrosine, β-(3,4-dihydroxyphenyl)-L-alanine, L-thyroxine, 4-hydroxy-L-proline, L-cysteine, L-methionine, L-ethionine, L-lanthionine, L-cystathionine, L- Cysteine, L-cysteic acid, L-aspartic acid, L-glutamic acid, S-(carboxymethyl)-L-cysteine, 4-aminobutyric acid, L-asparagine, L-glutamine, azacerine, L-arginine, L-canavanine, L-citrulline, δ-hydroxy-L-lysine, creatine, L-kynurenine, L-histidine, 1-methyl-L-histidine, 3-methyl-L-histidine, ergothioneine, L-tri Amino acids such as putophane, actinomycin C1, apamin, angiotensin I, angiotensin II, and antipyne; imines such as dithizone, cuproin (2,2'-biquinoline), neocuproin (2,9-dimethyl-1,10-phenanthroline), vasocuproin (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), and cuperazone (biscyclohexanone oxarylhydrazone);Benzimidazole-2-thiol, triazinedithiol, triazinetrithiol, 2-[2-(benzothiazolyl)]thiopropionic acid, 2-[2-(benzothiazolyl)]thiobutyric acid, 2-mercaptobenzothiazole, 1,2,3-triazole, 1,2,4-triazole, 3-amino-1H-1,2,4-triazole, benzotriazole, 1-hydroxybenzotriazole, 1-dihydroxypropylbenzotriazole, 2,3-dicarboxypropylbenzotriazole, 4-hydroxybenzotriazole, 4-carboxyl-1H-benzotriazole, 4-carboxyl-1H-be Examples of azoles include benzotriazole methyl ester, 4-carboxyl-1H-benzotriazole butyl ester, 4-carboxyl-1H-benzotriazole octyl ester, 5-hexylbenzotriazole, [1,2,3-benzotriazolyl-1-methyl][1,2,4-triazolyl-1-methyl][2-ethylhexyl]amine, tolyltriazole, naphthotriazole, bis[(1-benzotriazolyl)methyl]phosphonic acid, etc.; mercaptans such as nonyl mercaptan and dodecyl mercaptan; sugars such as glucose and cellulose, etc. Two or more of these may be used in combination. From the viewpoint of achieving both a high polishing rate and a low etching rate, the amount of the protective film-forming agent is preferably 0.0001 mol to 0.05 mol, more preferably 0.0003 mol to 0.005 mol, and even more preferably 0.0005 mol to 0.0035 mol per 100 g of the chemical mechanical polishing composition. ;

[0096] The metal oxide dissolving agent is preferably at least one of organic acids, organic acid esters, ammonium salts of organic acids, and sulfuric acid. The metal oxide dissolving agent is preferably water-soluble and may be formulated in aqueous solution. Specific examples include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid, 4-methylpentanoic acid, n-heptanoic acid, 2-methylhexanoic acid, n-octanoic acid, 2-ethylhexanoic acid, benzoic acid, glycolic acid, salicylic acid, glyceric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, malic acid, tartaric acid, citric acid, and other organic acids; esters of these organic acids; salts of these organic acids (ammonium salts, etc.); sulfuric acid, nitric acid, ammonia, ammonium salts (e.g., ammonium persulfate, ammonium nitrate, ammonium chloride, etc.); chromic acid, etc. Two or more of these may be used in combination. From the viewpoint of maintaining a low etching rate, the amount of the metal oxide dissolving agent blended is preferably 0 mol to 0.005 mol, more preferably 0.00005 mol to 0.0025 mol, and even more preferably 0.0005 mol to 0.0015 mol per 100 g of the chemical mechanical polishing composition.

[0097] Examples of polymers other than the copolymer (P) include polyacrylic acid or its salts, polymethacrylic acid or its salts, polyamic acid and its salts, polyacrylamide, polyvinyl alcohol, polyvinylpyrrolidone, polysaccharides, and two or more of these may be used.

[0098] The pH of the chemical mechanical polishing composition is preferably 4.0 or higher, more preferably 8.0 or higher, from the viewpoint of the overall planarization characteristics and polishing speed of the workpiece, and preferably 12.0 or lower, from the viewpoint of the dispersibility of inorganic particles. The pH can be adjusted by the amount of acid component, alkali component, and buffer added. Examples of the acid component include sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, oxalic acid, and maleic acid. The acid component may also be used in the form of a salt, such as ammonium sulfate, ammonium nitrate, or ammonium oxalate. Examples of the alkali component include ammonia, sodium hydroxide, potassium hydroxide, and tetramethylammonium hydroxide (TMAH). Examples of the buffer include phosphates.

[0099] The polishing composition described above can be applied to polishing workpieces having various shapes and materials. The shape of the workpiece is not particularly limited. Examples of materials for the workpiece include metals or metalloids such as silicon, aluminum, nickel, tungsten, copper, tantalum, titanium, stainless steel, and germanium, or alloys thereof; glassy materials such as quartz glass, aluminosilicate glass, and glassy carbon; ceramic materials such as alumina, silica, sapphire, silicon nitride, tantalum nitride, and titanium carbide; compound semiconductor substrate materials such as silicon carbide, gallium nitride, and gallium arsenide; and resin materials such as polyimide resin. The workpiece may also be composed of multiple materials from among these.

[0100] From the viewpoint of efficient planarization, the workpiece to be polished is preferably one on which a film containing silicon and having an uneven, stepped shape is formed on the substrate surface. Examples of silicon-containing films include silicon oxide such as TEOS (Tetraethoxysilane), quartz, and glass; silicon oxide doped with elements such as phosphorus and boron, such as BPSG (Boro-Phosphor-Silicate Glass) and PSG (Phosphor-Silicate Glass); silicon nitride; and polysilicon.

[0101] When polishing using the polishing composition, the polishing composition is supplied to the surface of the polishing pad while the pressed polishing pad and the object to be polished are moved relative to each other to polish the surface. The polishing pad is not particularly limited, but may be a nonwoven fabric type, suede type, polyurethane type, one containing abrasive grains, one without abrasive grains, etc.

[0102] The present invention will be described in more detail below based on specific examples. The present invention is not limited in any way to the following examples, and can be implemented with appropriate modifications without changing its essence. The polymerization rate, number average molecular weight, and molecular weight distribution of the copolymer were evaluated according to the method described below.

[0103] The meanings of the abbreviations are as follows: BTEE: Ethyl-2-methyl-2-n-butylteranyl-propionate MBMP: Methoxybutyl-β-mercaptopropionate AIBN: 2,2'-azobis(isobutyronitrile) ME11EGA: Polyethylene glycol (degree of polymerization = 11) methyl ether acrylate (manufactured by Green, KOMERATE-A040TT) ME9EGA: Polyethylene glycol (degree of polymerization = 9) methyl ether acrylate (manufactured by NOF Corporation, BREMMER® AME-400) BA: n-butyl acrylate CHA: Cyclohexyl acrylate VI: 1-vinylimidazole VP: N-vinyl-2-pyrrolidone 4VPy: 4-vinylpyridine DMAEA: Dimethylaminoethyl acrylate PMA: Propylene glycol monomethyl ether acetate MeOH: Methanol

[0104] (Polymerization rate) Using a nuclear magnetic resonance (NMR) measurement device (Bruker BioSpin, model: AVANCE500 (frequency 500 MHz)), 1 ¹H-NMR was measured (solvent: CDCl3, internal standard: tetramethylsilane). The integral ratio of monomer-derived peaks and polymer-derived peaks was determined from the obtained NMR spectrum to calculate the monomer polymerization rate.

[0105] (Number-average molecular weight and molecular weight distribution) These were determined by gel permeation chromatography (GPC) using a high-performance liquid chromatograph (Tosoh, model HLC-8320). One SHODEX KF-603 column (φ6.0 mm × 150 mm) (SHODEX) was used, with a lithium bromide (10 mmol / L) - acetate (10 mmol / L) - methylpyrrolidone solution as the mobile phase, and a differential refractometer as the detector. The measurement conditions were a column temperature of 40°C, a sample concentration of 20 mg / mL, a sample injection volume of 10 μm, and a flow rate of 0.2 mL / min. A calibration curve was created using polystyrene (molecular weights 70, 500, 37,900, 19,920, 10,200, 4,290, 2,630, 1,150) as standard substances, and the weight-average molecular weight (Mw) and number-average molecular weight (Mn) were measured. The molecular weight distribution (Mw / Mn) was calculated from these measurements.

[0106] <Synthesis of Copolymer> (Copolymer No. 1) The first-stage monomers, AIBN, and solvent from Table 1 were charged into a flask equipped with a nitrogen gas inlet tube and a stirrer. After purging with nitrogen, BTEE was added and the reaction was carried out under the conditions in Table 1 to polymerize block A. Next, a mixed solution of the second-stage monomers, polymerization agent, and solvent from Table 1 was pre-purged with nitrogen and added to the reaction solution. The reaction was carried out under the conditions in Table 1 to polymerize block B. After the reaction was complete, the reaction solution was poured into n-heptane while stirring. Copolymer No. 1 was obtained by suction filtration and drying of the precipitated polymer.

[0107] (Copolymers No. 2-6, 10-13) Copolymers No. 2-6 and 10-13 were prepared in the same manner as the preparation method for copolymer No. 1. Table 1 shows the monomers, polymerization agents, solvents, reaction conditions, and polymerization rates used.

[0108] (Copolymer No. 7) The first stage monomers from Table 1, AIBN, and solvent were charged into a flask equipped with a nitrogen gas inlet tube and a stirrer. After purging with nitrogen, BTEE was added, and polymerization was carried out under the conditions in Table 1. After the reaction was complete, the reaction solution was poured into a stirred n-heptane. Copolymer No. 7 was obtained by suction filtration and drying of the precipitated polymer.

[0109] (Copolymer No. 8) The first-stage monomers, solvent, and polymerization agent from Table 1 were charged into a flask equipped with a stirrer, and polymerization was carried out by reaction under the conditions in Table 1. After the reaction was complete, the reaction solution was poured into n-heptane while stirring. Copolymer No. 8 was obtained by suction filtration and drying of the precipitated polymer.

[0110] (Copolymer No. 9) Copolymer No. 9 was prepared in the same manner as the preparation method for copolymer No. 8. Table 1 shows the monomers, polymerization agents, solvents, reaction conditions, and polymerization rates used.

[0111] Tables 2 and 3 show the composition of each copolymer. The content of each structural unit in the copolymer was calculated from the charge ratio and polymerization rate of the monomers used in the polymerization reaction.

[0112]

[0113] <Preparation of Compositions> Compositions No. 1 to 17 were prepared by weighing 500 mg of the inorganic particles shown in Tables 2 and 3, 100 mg of the copolymer, and 5 mL of a pH standard aqueous solution of neutral phosphate (pH 6.8) into a container and stirring with a vortex stirrer for 10 minutes.

[0114]

[0115]

[0116] The inorganic particles used in Tables 2 and 3 are as follows: Ceria: Cerium oxide nanopowder (Sigma-Aldrich, primary particle BET specific surface area diameter: less than 50 nm, density (25°C): 7.13 g / cm³) 3 ) Alumina: Alumina beads CB-P02 (manufactured by Resonaq, primary particle BET specific surface area diameter: 2.73 μm, density (25°C): 2.0 g / cm³) 3 )

[0117] (Settling Test) The composition immediately after preparation was left to stand in an atmosphere of 25°C, and the settling of inorganic particles was observed visually. The settling suppression effect was evaluated according to the following criteria. The evaluation results are shown in Tables 2 and 3. A: After 15 minutes, the inorganic particles are completely dispersed without settling. B: After 15 minutes, about 1 / 4 of the inorganic particles have settled, but they are dispersed. C: After 15 minutes, about 1 / 2 of the inorganic particles have settled, but they are dispersed. D: After 15 minutes, the inorganic particles have completely settled.

[0118] Compositions No. 1-7 and 15-17 contain inorganic particles, a copolymer (P) obtained by living polymerization, and water, wherein the copolymer (P) contains structural units (a-1) having a structure represented by formula (1) in its side chain and structural units (b-1) having an azole structure in its side chain. In these compositions No. 1-7 and 15-17, sedimentation of inorganic particles was suppressed.

[0119] Composition No. 8 is the case where copolymer No. 8, obtained by free radical polymerization (FRP), is used, and contains structural units (a-1) having a structure represented by formula (1) in the side chain and structural units (b-1) having an azol structure in the side chain. Composition No. 9 is the case where copolymer No. 9, composed solely of vinylimidazole, is used. Compositions No. 10 to 14 are the cases where copolymers No. 10 to 13, which do not contain structural units (b-1) having an azol structure in the side chain, are used. These compositions No. 8 to 14 were unable to suppress the sedimentation of inorganic particles.

[0120] <Dispersibility Test> Ceria (manufactured by VMA-GETZMANN GmbH) as inorganic particles was used in a bead mill (product name: DISPERMAT CA, manufactured by VMA-GETZMANN GmbH). 31.0 g of (25°C), 25 parts by mass of the copolymer shown in Table 4 per 100 parts by mass of inorganic particles, and water were added to achieve a solid content concentration of 5% by mass. 50 g of zirconia beads (φ0.3 mm) were then added, and the mixture was stirred at 3000 rpm for 2 hours. After stirring, the beads were filtered off to prepare compositions No. 18 to 20. Viscosity and particle size evaluations were performed on the compositions, and the results are shown in Table 4.

[0121] (Viscosity) Viscosity (mPa·s) was measured using an E-type viscometer (product name: RE-80L, manufactured by Toki Sangyo Co., Ltd.) with a cone rotor (0.8° × R24) at 25°C and a rotor rotation speed of 50 rpm.

[0122] (Particle Size) The particle size of inorganic particles in the composition was measured at 25°C using a concentrated particle size analyzer (product name: FPAR-1000, manufactured by Otsuka Electronics). Samples were diluted with water as needed. Measurements were performed on the composition immediately after preparation.

[0123]

[0124] As shown in Table 4, copolymers No. 3 and 7 were confirmed to have excellent dispersibility of inorganic particles. Furthermore, when comparing composition No. 18 and composition No. 19, composition No. 1, which uses copolymer No. 3 (a block copolymer), showed superior dispersion performance of inorganic particles compared to composition No. 19, which uses copolymer No. 7 (a random copolymer).

[0125] <Polishing Test> Polishing tests were conducted using the following polishing compositions No. 21 to 23, with silicon wafers (manufactured by Advantec) coated with a P-TEOS film (film thickness: approximately 1000 nm) as the substrate. Polishing was performed using a polishing test machine (manufactured by Musashino Electronics, product name: MA-200e) and a polishing pad (manufactured by Nitta DuPont, product name: IC1000, diameter 8 inches, grooved). The polishing conditions were a pad pressure of 4.5 kPa, a rotation speed of 80 rpm, a polishing composition flow rate of 2.2 mL / min, and a polishing time of 5 minutes. The film thickness at the center and corners of the wafer after polishing was measured using a film thickness gauge (manufactured by Filmetrics, product name: FILMETRICS F20-UVX) to evaluate flatness, and the results are shown in Table 5.

[0126] Compositions for polishing Nos. 21 and 22 were prepared by mixing ceria slurry (manufactured by Fujimi Incorporated, trade name: CE POL 132) as inorganic particles in water so that the inorganic particle content was 1% by mass, and mixing the copolymer shown in Table 5 so that the amount was 1 part by mass with respect to 100 parts by mass of the inorganic particles. Composition for polishing No. 23 was prepared by mixing ceria slurry (manufactured by Fujimi Incorporated, trade name: CE POL 132) as inorganic particles in water so that the inorganic particle content was 1% by mass.

[0127]

[0128] As shown in Table 5, in Composition for polishing No. 23 which does not contain a copolymer, the difference between the center and the corner of the wafer was 59 nm, whereas in Composition for polishing No. 21 which contains Copolymer No. 3, the difference was reduced to 29 nm, and the flatness of the film thickness after polishing was improved. In Composition for polishing No. 22 which contains Copolymer No. 10, the difference increased to 135 nm and the flatness deteriorated. From the above results, it was found that the flatness of polishing is improved by blending Copolymer No. 3 into the composition for polishing.

[0129] The present invention includes the following aspects.

[0130] (Aspect 1) A composition containing inorganic particles, a copolymer (P) obtained by living polymerization, and water, wherein the copolymer (P) contains a structural unit (a-1) having a structure represented by formula (1) in the side chain and a structural unit (b-1) having an azole structure in the side chain. *-R 13 -(OR 12 ) m1 -OR 11 (1) [In formula (1), R 11 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R 12 represents an alkylene group having 1 to 3 carbon atoms. R 13 represents an alkylene group having 1 to 3 carbon atoms. m1 represents an integer of 0 to 30. When m1 is 2 or more, a plurality of R 12 may be the same or different from each other. * represents a bond. ]

[0131] (Aspect 2) The composition according to Aspect 1, wherein the structural unit (a-1) is a structural unit represented by formula (2).

[0132] [In formula (2), R 21 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R 22 represents an alkylene group having 1 to 3 carbon atoms. R 23 represents an alkylene group having 1 to 3 carbon atoms. R 24 represents a hydrogen atom or a methyl group. m2 represents an integer of 0 to 30. When m2 is 2 or more, the plurality of R 22 may be the same or different from each other. ]

[0133] (Aspect 3) The composition according to Aspect 1 or 2, wherein the structural unit (b-1) is a structural unit represented by formula (3).

[0134] [In formula (3), R 31 represents an alkyl group having 1 to 3 carbon atoms. m3 represents an integer of 0 to 3. When m3 is 2 or more, the plurality of R 31 may be the same or different from each other. ]

[0135] (Aspect 4) The composition according to any one of Aspects 1 to 3, wherein the mass ratio ((a-1) / (b-1)) of the structural unit (a-1) to the structural unit (b-1) in the copolymer (P) is 0.5 to 5.0.

[0136] (Aspect 5) The composition according to any one of Aspects 1 to 4, wherein the content of the structural unit (a-1) is 30% to 90% by mass in 100% by mass of the copolymer (P), and the content of the structural unit (b-1) is 9% to 70% by mass in 100% by mass of the copolymer (P).

[0137] (Aspect 6) The composition according to any one of Aspects 1 to 5, wherein the number average molecular weight of the copolymer (P) is 4,000 to 30,000.

[0138] (Aspect 7) The composition according to any one of aspects 1 to 6, wherein the molecular weight distribution (Mw / Mn) of the copolymer (P) is 4.0 or less.

[0139] (Aspect 8) The composition according to any one of aspects 1 to 7, wherein the living polymerization is living radical polymerization using an organotellurium compound.

[0140] (Aspect 9) The composition according to any one of aspects 1 to 8, wherein the copolymer (P) is a block copolymer having an A block and a B block, the A block contains a structural unit (a-1), and the B block contains a structural unit (b-1).

[0141] (Aspect 10) The composition according to aspect 9, wherein the mass ratio of block A to block B in the copolymer (block A / block B) is 50 / 50 to 90 / 10.

[0142] (Aspect 11) The density of the inorganic particles at 25°C is 2 g / cm³ 3 The composition described above, according to any one of embodiments 1 to 10.

[0143] (Aspect 12) The composition according to any one of aspects 1 to 11, wherein the inorganic particles are metal oxides.

[0144] (Aspect 13) The composition according to any one of aspects 1 to 12, wherein the inorganic particles are ceria.

[0145] (Aspect 14) The composition according to any one of aspects 1 to 13, wherein the content of the copolymer (P) is 0.01 parts by mass to 30 parts by mass per 100 parts by mass of the inorganic particles.

[0146] (Aspect 15) The composition according to any one of aspects 1 to 14, which is a chemical mechanical polishing composition used for surface planarization of an insulating layer and / or wiring layer of a semiconductor device.

[0147] The composition of the present invention can be suitably used as an abrasive composition using inorganic particles.

Claims

1. A composition containing inorganic particles, a copolymer (P) obtained by living polymerization, and water, wherein the copolymer (P) contains a structural unit (a-1) having a structure represented by formula (1) in its side chain, and a structural unit (b-1) having an azole structure in its side chain. *-R 13 - ( OR 12 ) m1 -OR 11 (1) [In equation (1), R 11 R represents a hydrogen atom or an alkyl group with 1 to 3 carbon atoms. 12 R represents an alkylene group with 1 to 3 carbon atoms. 13 R represents an alkylene group with 1 to 3 carbon atoms. m1 is an integer from 0 to 30. If m1 is 2 or greater, there are multiple R groups. 12 These may be the same or different. * represents a combination.

2. The composition according to claim 1, wherein the structural unit (a-1) is a structural unit represented by the formula (2). [In the formula (2), R 21 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R 22 represents an alkylene group having 1 to 3 carbon atoms. R 23 represents an alkylene group having 1 to 3 carbon atoms. R 24 represents a hydrogen atom or a methyl group. m2 represents an integer of 0 to 30. When m2 is 2 or more, a plurality of R 22 may be the same or different from each other. ] 3. The composition according to claim 1 or 2, wherein the structural unit (b-1) is a structural unit represented by formula (3). [In equation (3), R 31 R represents an alkyl group with 1 to 3 carbon atoms. m3 is an integer from 0 to 3. Note that if m3 is 2 or more, there are multiple R groups. 31 These may be the same or different.

4. The composition according to claim 1 or 2, wherein the mass ratio ((a-1) / (b-1)) of structural unit (a-1) to structural unit (b-1) in the copolymer (P) is 0.5 to 5.

0.

5. The composition according to claim 1 or 2, wherein the content of structural unit (a-1) is 30% to 90% by mass in 100% by mass of the copolymer (P), and the content of structural unit (b-1) is 9% to 70% by mass in 100% by mass of the copolymer (P).

6. The composition according to claim 1 or 2, wherein the number average molecular weight of the copolymer (P) is 4,000 to 30,000.

7. The composition according to claim 1 or 2, wherein the molecular weight distribution (Mw / Mn) of the copolymer (P) is 4.0 or less.

8. The composition according to claim 1 or 2, wherein the living polymerization is living radical polymerization using an organotellurium compound.

9. The composition according to claim 1 or 2, wherein the copolymer (P) is a block copolymer having an A block and a B block, the A block containing structural unit (a-1), and the B block containing structural unit (b-1).

10. The composition according to claim 9, wherein the mass ratio (A block / B block) of A block to B block in the copolymer (P) is 50 / 50 to 90 / 10.

11. The density of the inorganic particles at 25°C is 2 g / cm³. 3 The composition according to claim 1 or 2, as described above.

12. The composition according to claim 1 or 2, wherein the inorganic particles are a metal oxide.

13. The composition according to claim 1 or 2, wherein the inorganic particles are ceria.

14. The composition according to claim 1 or 2, wherein the content of the copolymer (P) is 0.01 parts by mass to 30 parts by mass per 100 parts by mass of the inorganic particles.

15. The composition according to claim 1 or 2, which is a chemical mechanical polishing composition used for surface planarization of an insulating layer and / or wiring layer of a semiconductor device.

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