Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09G—POLISHING COMPOSITIONS; SKI WAXES
  • C09G1/00—Polishing compositions
  • C09G1/02—Polishing compositions containing abrasives or grinding agents
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/14—Anti-slip materials; Abrasives
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P52/00—Grinding, lapping or polishing of wafers, substrates or parts of devices

Definitions

• the present invention relates to a polishing composition.
• This application claims priority based on Japanese Patent Application No. 2022-047444 filed on March 23, 2022, and the entire contents of that application are incorporated herein by reference.
• Precision polishing using a polishing composition is performed on the surfaces of materials such as metals, semimetals, nonmetals, and their oxides.
• the surface of a silicon wafer used as a component of a semiconductor device is generally finished into a high-quality mirror surface through a lapping process (rough polishing process) and a polishing process (precision polishing process).
• the polishing process typically includes a preliminary polishing process (preliminary polishing process) and a final polishing process (final polishing process).
• Patent Document 1 is cited as a technical document regarding polishing compositions mainly used for polishing semiconductor substrates such as silicon wafers.
• the polishing composition used has a polishing ability to efficiently polish the object to be polished.
• a polishing ability to efficiently polish the object to be polished.
• mechanical polishing action by abrasive grains and chemical polishing action (alkali etching) by basic compounds are used, and these actions result in high processing power. can be demonstrated.
• a polishing composition with high processing power is preferable because manufacturing efficiency and cost effectiveness can be improved.
• silica particles as abrasive grains, a polished surface with good quality can be efficiently achieved.
• the polishing composition used for polishing the above-mentioned substrate includes, for example, a polishing composition used for a final polishing process (particularly a final polishing process for semiconductor substrates such as silicon wafers and other substrates), etc. Performance may be required to achieve a high quality surface. Improving the surface quality of the polished surface (for example, reducing haze) can be achieved by including additives such as water-soluble polymers and surfactants in the polishing composition and protecting the substrate with the additives.
• Patent Document 1 discloses a polishing composition containing silica particles, a basic compound, and a water-soluble polymer.
• the above-mentioned water-soluble polymers and the like also suppress alkali etching, they may cause a decrease in processing power and, in turn, a decrease in manufacturing efficiency.
• the present invention was created in view of the above circumstances, and aims to provide a polishing composition that can obtain high surface quality and improve the polishing rate.
• a polishing composition containing (D) is provided. Since the polishing composition contains at least two types of water-soluble polymers (C1) and (C2), it is possible to obtain a polished surface with high surface quality (for example, low haze value). Further, according to the polishing composition containing the inorganic acid alkali metal salt (D), the polishing rate can be improved while maintaining the quality of the polished surface obtained by using two or more water-soluble polymers. can. That is, according to the polishing composition having the above composition, high surface quality can be obtained and the polishing rate can be improved.
• the first water-soluble polymer (C1) is a polyvinyl alcohol-based polymer. According to a polishing composition containing a polyvinyl alcohol polymer as the first water-soluble polymer (C1), a high-quality polished surface is easily obtained. By using a polyvinyl alcohol polymer as the first water-soluble polymer (C1) in combination with another water-soluble polymer as the second water-soluble polymer (C2), haze can be effectively improved. can do.
• the second water-soluble polymer (C2) is a polymer containing a nitrogen atom.
• a polishing composition containing a nitrogen atom-containing polymer as the second water-soluble polymer (C2) can easily provide a high-quality polished surface.
• haze can be effectively reduced. can be improved.
• the ratio (D/C2) of the content of the inorganic acid alkali metal salt (D) to the content of the second water-soluble polymer (C2) is 0.1 to 10 on a weight basis. It is within the range of .0.
• the polishing composition further includes at least one surfactant (E).
• the surfactant (E) By including the surfactant (E) in the polishing composition, haze can be reduced.
• the inorganic acid alkali metal salt (D) contained in the polishing composition can contribute to improving the polishing rate without impairing the effect of the surfactant (E). Therefore, according to the above composition, the polishing rate can be improved while maintaining the effect of including the surfactant (E) (high effect of improving the quality of the polished surface (specifically, haze)).
• the polishing composition contains two or more types of nonionic surfactants as the surfactant (E).
• the surfactant (E) By selecting and using two or more types of nonionic surfactants as the surfactant (E), the haze reduction effect can be better exhibited.
• the polishing composition disclosed herein can be preferably used for polishing surfaces made of silicon materials. By polishing a surface made of a silicon material using the polishing composition described above, a surface made of a high quality silicon material can be efficiently realized.
• the polishing composition disclosed herein may be a concentrate.
• the polishing composition disclosed herein can be manufactured, distributed, and stored as a concentrated liquid.
• the polishing composition disclosed herein contains silica particles (A).
• Silica particles (A) are particles that serve to mechanically polish the surface of an object to be polished, and are also referred to as abrasive grains. By including the silica particles (A) in the polishing composition, the polishing rate can be improved based on the mechanical polishing action caused by the inclusion of the silica particles (A).
• silica particles (A) it is particularly preferable to employ silica particles (A) as the abrasive grains. It is meaningful.
• silica particles (A) include colloidal silica, fumed silica, precipitated silica, and the like.
• the silica particles (A) can be used alone or in combination of two or more.
• the use of colloidal silica is particularly preferred since it is easy to obtain a polished surface with excellent surface quality after polishing.
• colloidal silica for example, colloidal silica produced using water glass (Na silicate) as a raw material by an ion exchange method, or colloidal silica produced by an alkoxide method (colloidal silica produced by a hydrolytic condensation reaction of alkoxysilane) is preferably employed. be able to.
• One type of colloidal silica can be used alone or two or more types can be used in combination.
• the true specific gravity of the silica constituting the silica particles (A) is preferably 1.5 or more, more preferably 1.6 or more, and even more preferably 1.7 or more.
• the upper limit of the true specific gravity of silica is not particularly limited, but is typically 2.3 or less, for example 2.2 or less.
• the average primary particle diameter of the silica particles (A) is not particularly limited, but from the viewpoint of polishing rate, etc., it is preferably 5 nm or more, more preferably 10 nm or more. From the viewpoint of obtaining higher polishing effects (for example, effects such as haze reduction and defect removal), the average primary particle diameter is preferably 15 nm or more, and more preferably 20 nm or more (for example, more than 20 nm). Further, from the viewpoint of preventing scratches, etc., the average primary particle diameter of the silica particles (A) is preferably 100 nm or less, more preferably 50 nm or less, and still more preferably 45 nm or less.
• the average primary particle diameter of the silica particles (A) may be 43 nm or less, may be less than 40 nm, may be less than 38 nm, may be less than 35 nm, It may be less than 32 nm, or may be less than 30 nm.
• the specific surface area can be measured using, for example, a surface area measuring device manufactured by Micromeritex, trade name "Flow Sorb II 2300".
• the average secondary particle diameter of the silica particles (A) is not particularly limited, and can be appropriately selected from a range of, for example, about 15 nm to 300 nm. From the viewpoint of improving the polishing rate, the average secondary particle diameter is preferably 30 nm or more, more preferably 35 nm or more. In some embodiments, the average secondary particle diameter may be, for example, 40 nm or more, 42 nm or more, and preferably 44 nm or more. Further, the average secondary particle diameter is usually advantageously 250 nm or less, preferably 200 nm or less, and more preferably 150 nm or less.
• the average secondary particle diameter is 120 nm or less, more preferably 100 nm or less, even more preferably 70 nm or less, for example, it may be 60 nm or less, or it may be 50 nm or less.
• the average secondary particle diameter refers to a particle diameter (volume average particle diameter) measured by a dynamic light scattering method.
• the average secondary particle diameter of the silica particles (A) can be measured, for example, by a dynamic light scattering method using "Nanotrack UPA-UT151” manufactured by Nikkiso Co., Ltd.
• the shape (outer shape) of the silica particles (A) may be spherical or non-spherical.
• specific examples of non-spherical particles include a peanut shape (ie, peanut shell shape), a cocoon shape, a confetti candy shape, a rugby ball shape, and the like.
• silica particles (A) in which most of the particles are peanut-shaped or cocoon-shaped can be preferably used.
• the average value of the length/breadth ratio (average aspect ratio) of the silica particles (A) is in principle 1.0 or more, preferably 1.05 or more, more preferably 1. .1 or more. Higher polishing rates may be achieved by increasing the average aspect ratio.
• the average aspect ratio of the silica particles (A) is preferably 3.0 or less, more preferably 2.0 or less, and even more preferably 1.5 or less, from the viewpoint of scratch reduction and the like.
• the shape (external shape) and average aspect ratio of the silica particles (A) can be determined, for example, by observation using an electron microscope.
• an electron microscope As a specific procedure for determining the average aspect ratio, for example, using a scanning electron microscope (SEM), each of a predetermined number (for example, 200) of silica particles (A) for which independent particle shapes can be recognized is Draw the smallest rectangle circumscribing the particle image. Then, for the rectangle drawn for each particle image, the length of the long side (value of the major axis) is divided by the length of the short side (value of the minor axis), and the value is calculated as the major axis / minor axis ratio (aspect ratio). ).
• the average aspect ratio can be determined by arithmetic averaging the aspect ratios of the predetermined number of particles.
• the polishing composition disclosed herein may contain abrasive grains other than silica particles (A) (hereinafter also referred to as “non-silica particles”) to the extent that the effects of the present invention are not significantly impaired.
• non-silica particles include inorganic particles, organic particles, and organic-inorganic composite particles.
• inorganic particles include oxide particles such as alumina particles, cerium oxide particles, chromium oxide particles, titanium dioxide particles, zirconium oxide particles, magnesium oxide particles, manganese dioxide particles, zinc oxide particles, red iron particles; silicon nitride particles; , nitride particles such as boron nitride particles; carbide particles such as silicon carbide particles and boron carbide particles; diamond particles; carbonates such as calcium carbonate and barium carbonate.
• organic particles include polymethyl methacrylate (PMMA) particles and poly(meth)acrylic acid particles (here, (meth)acrylic acid refers comprehensively to acrylic acid and methacrylic acid.) , polyacrylonitrile particles, etc.
• PMMA polymethyl methacrylate
• poly(meth)acrylic acid particles here, (meth)acrylic acid refers comprehensively to acrylic acid and methacrylic acid.
• polyacrylonitrile particles etc.
• One type of such non-silica particles may be used alone, or two or more types
• the technology disclosed herein can be preferably implemented in an embodiment in which substantially only silica particles (A) are used as abrasive grains.
• the proportion of silica particles (A) in the total amount of abrasive grains is suitably 90% by weight or more, preferably 95% by weight or more, more preferably 98% by weight or more (for example, 99 to 100% by weight). ).
• the polishing composition disclosed herein contains a basic compound (B).
• the basic compound (B) refers to a compound that dissolves in water and has the function of increasing the pH of an aqueous solution.
• the object to be polished can be efficiently polished due to its chemical polishing action (alkali etching).
• Basic compounds (B) include organic or inorganic basic compounds containing nitrogen, basic compounds containing phosphorus, alkali metal hydroxides, alkaline earth metal hydroxides, various carbonates and hydrogen carbonate. Salts and the like can be used, but the inorganic acid alkali metal salts (D) described below are not included.
• Examples of basic compounds containing nitrogen include quaternary ammonium compounds, ammonia, amines (preferably water-soluble amines), and the like.
• Examples of basic compounds containing phosphorus include quaternary phosphonium compounds.
• Such basic compounds (B) can be used alone or in combination of two or more.
• alkali metal hydroxides include potassium hydroxide, sodium hydroxide, and the like.
• carbonates or hydrogen carbonates include ammonium hydrogen carbonate, ammonium carbonate, potassium hydrogen carbonate, potassium carbonate, sodium hydrogen carbonate, sodium carbonate, and the like.
• Specific examples of amines include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, monoethanolamine, N-( ⁇ -aminoethyl)ethanolamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, anhydrous piperazine.
• quaternary phosphonium compounds include quaternary phosphonium hydroxides such as tetramethylphosphonium hydroxide and tetraethylphosphonium hydroxide.
• quaternary ammonium salts such as tetraalkylammonium salts and hydroxyalkyltrialkylammonium salts
• the anionic component in such quaternary ammonium salts can be, for example, OH ⁇ , F ⁇ , Cl ⁇ , Br ⁇ , I ⁇ , ClO 4 ⁇ , BH 4 ⁇ and the like.
• Examples of the above-mentioned quaternary ammonium compounds include quaternary ammonium salts in which the anion is OH - , ie, quaternary ammonium hydroxide.
• quaternary ammonium hydroxide examples include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrapentylammonium hydroxide, and tetrahexylammonium hydroxide.
• At least one basic compound selected from alkali metal hydroxides, quaternary ammonium hydroxides, and ammonia can be preferably used.
• potassium hydroxide, tetraalkylammonium hydroxide (eg, tetramethylammonium hydroxide), and ammonia are more preferred, and ammonia is particularly preferred.
• the polishing composition disclosed herein contains at least two types of water-soluble polymers (C).
• the polishing composition includes a first water-soluble polymer (C1) and a second water-soluble polymer (C2) as the water-soluble polymer (C).
• the second water-soluble polymer (C2) is a water-soluble polymer having a chemical structure different from that of the first water-soluble polymer (C1).
• the water-soluble polymer (C) can be useful for protecting the substrate surface, improving wettability of the substrate surface after polishing, and the like.
• the surface quality (for example, haze) after polishing can be improved.
• an excellent haze improving effect can be obtained.
• the water-soluble polymer (C) has a hydroxyl group, a carboxy group, an acyloxy group, a sulfo group, an amide structure, an imide structure, a quaternary ammonium structure, a heterocyclic structure, a vinyl structure, etc. in the molecule.
• Examples include compounds containing.
• the water-soluble polymer (C) for example, cellulose derivatives, starch derivatives, polymers containing oxyalkylene units, polyvinyl alcohol polymers, polymers containing nitrogen atoms, etc. can be used.
• the water-soluble polymer (C) may be a polymer derived from a natural product or a synthetic polymer.
• a polymer derived from a natural product is used as the water-soluble polymer (C).
• Polymers derived from natural products include cellulose derivatives and starch derivatives. Polymers derived from natural products may be used singly or in combination of two or more.
• a cellulose derivative is used as the water-soluble polymer (C).
• cellulose derivatives are polymers containing ⁇ -glucose units as the main repeating unit.
• Specific examples of cellulose derivatives include hydroxyethylcellulose (HEC), hydroxypropylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, methylcellulose, ethylcellulose, ethylhydroxyethylcellulose, carboxymethylcellulose, and the like.
• HEC hydroxyethylcellulose
• One type of cellulose derivative may be used alone, or two or more types may be used in combination.
• a starch derivative is used as the water-soluble polymer (C).
• Starch derivatives are polymers containing ⁇ -glucose units as main repeating units, and include pregelatinized starch, pullulan, carboxymethyl starch, cyclodextrin, and the like.
• One type of starch derivative may be used alone, or two or more types may be used in combination.
• a synthetic polymer is used as the water-soluble polymer (C).
• the effects of the technology disclosed herein are preferably exhibited in embodiments in which a synthetic polymer is used as the water-soluble polymer (C).
• One type of synthetic polymer may be used alone, or two or more types may be used in combination.
• a polymer containing oxyalkylene units is used as the water-soluble polymer (C).
• Polymers containing oxyalkylene units include polyethylene oxide (PEO), block copolymers of ethylene oxide (EO) and propylene oxide (PO) or butylene oxide (BO), and random copolymers of EO and PO or BO. etc. are exemplified.
• block copolymers of EO and PO or random copolymers of EO and PO are preferred.
• the block copolymer of EO and PO may be a diblock copolymer or triblock copolymer containing a PEO block and a polypropylene oxide (PPO) block.
• triblock copolymer examples include a PEO-PPO-PEO triblock copolymer and a PPO-PEO-PPO triblock copolymer. Usually, a PEO-PPO-PEO type triblock copolymer is more preferred.
• copolymer refers comprehensively to various copolymers such as random copolymers, alternating copolymers, block copolymers, and graft copolymers. be.
• the molar ratio (EO/PO) of EO and PO constituting the copolymer is determined from the viewpoint of solubility in water, washability, etc. It is preferably larger than 1, more preferably 2 or more, and even more preferably 3 or more (for example, 5 or more).
• a polyvinyl alcohol polymer is used as the water-soluble polymer (C).
• a polyvinyl alcohol-based polymer refers to a polymer containing vinyl alcohol units (hereinafter also referred to as "VA units") as repeating units.
• VA units vinyl alcohol units
• One type of polyvinyl alcohol-based polymer may be used alone, or two or more types may be used in combination.
• the polyvinyl alcohol-based polymer may contain only VA units as repeating units, or may contain repeating units other than VA units (hereinafter also referred to as "non-VA units") in addition to VA units.
• the polyvinyl alcohol polymer may be a random copolymer containing VA units and non-VA units, a block copolymer, an alternating copolymer, or a graft copolymer.
• the polyvinyl alcohol-based polymer may contain only one type of non-VA unit, or may contain two or more types of non-VA units.
• the polyvinyl alcohol-based polymer may be unmodified polyvinyl alcohol (unmodified PVA) or modified polyvinyl alcohol (modified PVA).
• unmodified PVA is produced by hydrolyzing (saponifying) polyvinyl acetate, and contains repeating units (-CH 2 -CH(OCOCH 3 )-) of vinyl polymerized structure of vinyl acetate and non-VA units.
• the degree of saponification of the unmodified PVA may be, for example, 60% or more, and from the viewpoint of water solubility, it may be 70% or more, 80% or more, or 90% or more.
• Polyvinyl alcohol-based polymers contain VA units, oxyalkylene groups, carboxy groups, (di)carboxylic acid groups, (di)carboxylic acid ester groups, phenyl groups, naphthyl groups, sulfo groups, amino groups, hydroxyl groups, amide groups, and imide groups. It may be a modified PVA containing a non-VA unit having at least one structure selected from a group, a nitrile group, an ether group, an ester group, and a salt thereof.
• a preferred example of the N-vinyl type monomer is N-vinylpyrrolidone.
• a suitable example of the N-(meth)acryloyl type monomer is N-(meth)acryloylmorpholine.
• the alkyl vinyl ether may be a vinyl ether having an alkyl group having 1 to 10 carbon atoms, such as propyl vinyl ether, butyl vinyl ether, 2-ethylhexyl vinyl ether, and the like.
• the vinyl ester of a monocarboxylic acid having 3 or more carbon atoms is a vinyl ester of a monocarboxylic acid having 3 or more carbon atoms and 7 or less carbon atoms, such as vinyl propanoate, vinyl butanoate, vinyl pentanoate, vinyl hexanoate, etc. obtain.
• Suitable examples of the above (di)acetone compound include diacetone (meth)acrylamide and acetylacetone.
• an acetalized polyvinyl alcohol polymer is used as the polyvinyl alcohol polymer.
• the acetalized polyvinyl alcohol polymer include modified PVA in which some of the VA units contained in the polyvinyl alcohol polymer are acetalized.
• Modified PVA acetalized PVA (ac-PVA)
• acetalized PVA ac-PVA
• acetalized PVA ac-PVA
• an acetalized polyvinyl alcohol-based polymer is obtained by an acetalization reaction between a polyvinyl alcohol-based polymer and an aldehyde compound.
• the aldehyde compound has 1 to 7 carbon atoms, more preferably 2 to 7 carbon atoms.
• aldehyde compounds include formaldehyde; linear or branched alkyl aldehydes such as acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, t-butyraldehyde, pentylaldehyde, and hexylaldehyde; cyclohexanecarbaldehyde, benzaldehyde, etc.
• aldehyde examples include alicyclic or aromatic aldehydes. These may be used alone or in combination of two or more. Further, except for formaldehyde, one or more hydrogen atoms may be substituted with halogen or the like.
• straight-chain or branched alkyl aldehydes are preferred because they have high solubility in water and facilitate the acetalization reaction, and among these, acetaldehyde, propylaldehyde, n-butyraldehyde, and n-pentylaldehyde are preferred. It is more preferable that there be.
• aldehyde compounds having 8 or more carbon atoms such as 2-ethylhexylaldehyde, nonylaldehyde, and decylaldehyde may be used.
• Acetalized polyvinyl alcohol polymer has a VA unit which is a structural part represented by the following chemical formula: -CH 2 -CH(OH)-; and an acetalized structure represented by the following general formula (1). units (hereinafter also referred to as "VAC units").
• R is a hydrogen atom or a linear or branched alkyl group, and the alkyl group may be substituted with a functional group.
• R in the above formula (1) is a hydrogen atom or a straight chain or branched alkyl group having 1 to 6 carbon atoms.
• R may be one type of these or a combination of two or more types. From the viewpoint of improving haze reduction performance, R is preferably a straight or branched alkyl chain having 1 to 6 carbon atoms.
• the degree of acetalization of the acetalized polyvinyl alcohol-based polymer can be 1 mol% or more, may be 5 mol% or more, preferably 10 mol% or more, and more preferably The content is 15 mol% or more, more preferably 20 mol% or more, particularly preferably 25 mol% or more (for example, 27 mol% or more).
• the degree of acetalization of the acetalized polyvinyl alcohol-based polymer is preferably less than 60 mol%, more preferably 50 mol% or less, more preferably 40 mol% or less, particularly preferably 35 mol% or less. (for example, 33 mol% or less).
• the "degree of acetalization” refers to the proportion of acetalized structural units (VAC units) to all repeating units constituting the acetalized polyvinyl alcohol polymer.
• polyvinyl alcohol polymer cationically modified polyvinyl alcohol into which a cationic group such as a quaternary ammonium structure has been introduced may be used.
• the above-mentioned cation-modified polyvinyl alcohol is introduced with a cationic group derived from a monomer having a cationic group such as diallyldialkylammonium salt, N-(meth)acryloylaminoalkyl-N,N,N-trialkylammonium salt, etc.
• a cationic group derived from a monomer having a cationic group such as diallyldialkylammonium salt, N-(meth)acryloylaminoalkyl-N,N,N-trialkylammonium salt, etc.
• the vinyl alcohol polymer has a structural moiety in which the non-VA unit is represented by the chemical formula: -CH 2 -CH(CR 5 (OR 8 )-CR 6 (OR 9 )-R 7 )-.
• R 5 to R 7 each independently represent a hydrogen atom or an organic group
• R 8 and R 9 each independently represent a hydrogen atom or R 10 -CO- (wherein R 10 represents an alkyl group).
• modified PVA include modified PVA having a 1,2-diol structure in its side chain.
• the ratio of the number of moles of VA units to the number of moles of all repeating units constituting the polyvinyl alcohol polymer may be, for example, 5% or more, 10% or more, 20% or more, or 30% or more. .
• the molar ratio of the VA units may be 50% or more, 65% or more, 75% or more, 80% or more, It may be 90% or more (for example, 95% or more, or 98% or more).
• Substantially 100% of the repeating units constituting the polyvinyl alcohol polymer may be VA units.
• substantially 100% means that the polyvinyl alcohol polymer does not contain non-VA units, at least intentionally, and typically the number of moles of non-VA units relative to the number of moles of all repeating units.
• the ratio is less than 2% (for example, less than 1%), including the case where it is 0%.
• the ratio of the number of moles of VA units to the number of moles of all repeating units constituting the polyvinyl alcohol-based polymer may be, for example, 95% or less, may be 90% or less, and may be 80% or less. It may be 70% or less.
• the content of VA units (content on a weight basis) in the polyvinyl alcohol-based polymer may be, for example, 5% by weight or more, 10% by weight or more, 20% by weight or more, or 30% by weight or more.
• the content of the VA unit may be 50% by weight or more (for example, more than 50% by weight), 70% by weight or more, and 80% by weight or more (for example, more than 50% by weight). For example, it may be 90% by weight or more, 95% by weight or more, or 98% by weight or more).
• Substantially 100% by weight of the repeating units constituting the polyvinyl alcohol polymer may be VA units.
• substantially 100% by weight means that at least intentionally no non-VA units are contained as repeating units constituting the polyvinyl alcohol-based polymer, typically non-VA units in the polyvinyl alcohol-based polymer. This means that the content of is less than 2% by weight (for example, less than 1% by weight). In some other embodiments, the content of VA units in the polyvinyl alcohol-based polymer may be, for example, 95% by weight or less, 90% by weight or less, 80% by weight or less, or 70% by weight or less. .
• the polyvinyl alcohol-based polymer may contain multiple polymer chains with different contents of VA units in the same molecule.
• the polymer chain refers to a portion (segment) that constitutes a part of one molecule of polymer.
• polyvinyl alcohol-based polymers have a polymer chain A with a content of VA units greater than 50% by weight and a content of VA units less than 50% by weight (i.e. a content of non-VA units greater than 50% by weight). ) may be included in the same molecule.
• the polymer chain A may contain only VA units as repeating units, or may contain non-VA units in addition to VA units.
• the content of VA units in the polymer chain A may be 60% by weight or more, 70% by weight or more, 80% by weight or more, or 90% by weight or more. In some embodiments, the content of VA units in polymer chain A may be 95% by weight or more, or 98% by weight or more. Substantially 100% by weight of the repeating units constituting the polymer chain A may be VA units.
• Polymer chain B may contain only non-VA units as repeating units, or may contain VA units in addition to non-VA units.
• the content of non-VA units in polymer chain B may be 60% by weight or more, 70% by weight or more, 80% by weight or more, or 90% by weight or more. In some embodiments, the content of non-VA units in polymer chain B may be 95% by weight or more, and may be 98% by weight or more. Substantially 100% by weight of the repeating units constituting polymer chain B may be non-VA units.
• polyvinyl alcohol polymers containing polymer chain A and polymer chain B in the same molecule include block copolymers and graft copolymers containing these polymer chains.
• the above-mentioned graft copolymer may be a graft copolymer having a structure in which a polymer chain B (side chain) is grafted onto a polymer chain A (main chain), and a polymer chain A (side chain) is grafted onto a polymer chain B (main chain). It may also be a graft copolymer with a structure in which a chain) is grafted.
• a polyvinyl alcohol polymer having a structure in which polymer chain B is grafted onto polymer chain A can be used.
• polymer chain B examples include a polymer chain whose main repeating unit is a repeating unit derived from an N-vinyl type monomer; a polymer chain whose main repeating unit is a repeating unit derived from an N-(meth)acryloyl type monomer; Polymer chains whose main repeating units are repeating units derived from vinyl dicarboxylate such as fumaric acid, maleic acid, and maleic anhydride; Main repeating units whose main repeating units are repeating units derived from aromatic vinyl monomers such as styrene and vinylnaphthalene. Examples include polymer chains; polymer chains having oxyalkylene units as main repeating units; and the like.
• the main repeating unit refers to a repeating unit contained in an amount exceeding 50% by weight, unless otherwise specified.
• a preferred example of the polymer chain B is a polymer chain whose main repeating unit is an N-vinyl type monomer, that is, an N-vinyl polymer chain.
• the content of repeating units derived from N-vinyl monomers in the N-vinyl polymer chain is typically more than 50% by weight, may be 70% by weight or more, and may be 85% by weight or more. The content may be 95% by weight or more.
• Substantially all of the polymer chain B may be repeating units derived from N-vinyl type monomers.
• examples of N-vinyl type monomers include monomers having a nitrogen-containing heterocycle (eg, a lactam ring) and N-vinyl linear amides.
• Specific examples of N-vinyllactam type monomers include N-vinylpyrrolidone, N-vinylpiperidone, N-vinylmorpholinone, N-vinylcaprolactam, N-vinyl-1,3-oxazin-2-one, N-vinyl- Examples include 3,5-morpholinedione.
• Specific examples of the N-vinyl chain amide include N-vinylacetamide, N-vinylpropionamide, N-vinylbutyric acid amide, and the like.
• Polymer chain B is, for example, an N-vinyl polymer chain in which more than 50% by weight (for example, 70% or more, or 85% or more, or 95% or more) of its repeating units are N-vinylpyrrolidone units. obtain. Substantially all of the repeating units constituting polymer chain B may be N-vinylpyrrolidone units.
• polymer chain B is a polymer chain whose main repeating unit is a repeating unit derived from an N-(meth)acryloyl type monomer, that is, an N-(meth)acryloyl-based polymer chain.
• the content of repeating units derived from N-(meth)acryloyl type monomers in the N-(meth)acryloyl-based polymer chain is typically more than 50% by weight, and may be 70% by weight or more, and 85% by weight or more. It may be at least 95% by weight, or at least 95% by weight.
• Substantially all of the polymer chain B may be repeating units derived from N-(meth)acryloyl type monomers.
• examples of N-(meth)acryloyl type monomers include linear amides having an N-(meth)acryloyl group and cyclic amides having an N-(meth)acryloyl group.
• linear amides having an N-(meth)acryloyl group include (meth)acrylamide; N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, N-isopropyl( N-alkyl (meth)acrylamide such as meth)acrylamide, Nn-butyl(meth)acrylamide; N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-dipropyl(meth)acrylamide ) acrylamide, N,N-dialkyl (meth)acrylamide such as N,N-diisopropyl (meth)acrylamide, N,N-di(n-butyl
• polymer chain B is a polymer chain containing an oxyalkylene unit as a main repeating unit, that is, an oxyalkylene polymer chain.
• the content of oxyalkylene units in the oxyalkylene polymer chain is typically more than 50% by weight, may be 70% by weight or more, may be 85% by weight or more, and may be 95% by weight or more. There may be. Substantially all of the repeating units contained in polymer chain B may be oxyalkylene units.
• oxyalkylene units include oxyethylene units, oxypropylene units, oxybutylene units, and the like. Each such oxyalkylene unit can be a repeating unit derived from the corresponding alkylene oxide.
• the number of oxyalkylene units contained in the oxyalkylene polymer chain may be one type, or two or more types. For example, it may be an oxyalkylene polymer chain containing a combination of oxyethylene units and oxypropylene units.
• those oxyalkylene units may be random copolymers of corresponding alkylene oxides, block copolymers, or alternating copolymers. It may be a polymer or a graft copolymer.
• polymer chain B examples include polymer chains containing repeating units derived from alkyl vinyl ethers (e.g. vinyl ethers having an alkyl group having 1 to 10 carbon atoms), monocarboxylic acid vinyl esters (e.g. vinyl ethers having an alkyl group having 1 to 10 carbon atoms); Examples include a polymer chain containing a repeating unit derived from a vinyl ester of three or more monocarboxylic acids, a polymer chain into which a cationic group (for example, a cationic group having a quaternary ammonium structure) is introduced, and the like.
• alkyl vinyl ethers e.g. vinyl ethers having an alkyl group having 1 to 10 carbon atoms
• monocarboxylic acid vinyl esters e.g. vinyl ethers having an alkyl group having 1 to 10 carbon atoms
• Examples include a polymer chain containing a repeating unit derived from a vinyl ester of three or more monocarboxy
• the polyvinyl alcohol polymer as the water-soluble polymer (C) in the technology disclosed herein is preferably a modified polyvinyl alcohol that is a copolymer containing VA units and non-VA units.
• the degree of saponification of the polyvinyl alcohol polymer as the water-soluble polymer (C) is usually 50 mol% or more, preferably 65 mol% or more, more preferably 70 mol% or more, for example 75 mol% or more. be. Note that the degree of saponification of the polyvinyl alcohol polymer is, in principle, 100 mol% or less.
• a nitrogen atom-containing polymer is used as the water-soluble polymer (C).
• a polishing composition containing a nitrogen atom-containing polymer can easily provide a high-quality polished surface.
• a polymer containing a nitrogen atom may typically be a polymer containing repeating units derived from a monomer having a nitrogen atom (a repeating unit containing a nitrogen atom).
• Non-limiting examples of polymers containing nitrogen atoms include polymers containing monomer units of the N-vinyl type; polymers containing monomer units of the N-(meth)acryloyl type; and the like.
• the nitrogen atom-containing polymers may be used alone or in combination of two or more.
• an N-vinyl type polymer may be used as the nitrogen atom-containing polymer.
• N-vinyl type polymers include polymers containing repeating units derived from monomers having nitrogen-containing heterocycles (eg, lactam rings). Examples of such polymers include homopolymers and copolymers of N-vinyl lactam type monomers (e.g., copolymers with a copolymerization ratio of more than 50% by weight of N-vinyl lactam type monomers), N-vinyl lactam type monomers, Homopolymers and copolymers of linear amide (for example, copolymers in which the copolymerization ratio of N-vinyl linear amide exceeds 50% by weight), etc. are included.
• N-vinyl lactam type monomers that is, compounds having a lactam structure and an N-vinyl group in one molecule
• N-vinylpyrrolidone VP
• N-vinylpiperidone N-vinylmorpholinone
• VC -vinylcaprolactam
• N-vinyl-1,3-oxazin-2-one N-vinyl-3,5-morpholinedione and the like.
• polymers containing N-vinyllactam type monomer units include polyvinylpyrrolidone, polyvinylcaprolactam, random copolymers of VP and VC, one or both of VP and VC and other vinyl monomers (e.g.
• N-vinyl chain amide examples include N-vinylacetamide, N-vinylpropionamide, N-vinylbutyric acid amide, and the like.
• an N-(meth)acryloyl type polymer may be preferably used as the water-soluble polymer (C) (nitrogen-containing polymer).
• C water-soluble polymer
• the effects of the technology disclosed herein can be more preferably realized in a composition containing an N-(meth)acryloyl type polymer.
• N-(meth)acryloyl type polymers include homopolymers and copolymers of N-(meth)acryloyl type monomers (typically, the copolymerization ratio of N-(meth)acryloyl type monomers is 50% by weight). % copolymer).
• Examples of N-(meth)acryloyl type monomers include linear amides having N-(meth)acryloyl groups and cyclic amides having N-(meth)acryloyl groups.
• linear amides having an N-(meth)acryloyl group include (meth)acrylamide; N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, N-isopropyl( N-alkyl (meth)acrylamide such as meth)acrylamide, Nn-butyl(meth)acrylamide; N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-dipropyl(meth)acrylamide ) acrylamide, N,N-dialkyl (meth)acrylamide such as N,N-diisopropyl (meth)acrylamide, N,N-di(n-butyl)(meth)acrylamide; and the like.
• polymers containing a linear amide having an N-(meth)acryloyl group as a monomer unit include a homopolymer of N-isopropylacrylamide and a copolymer of N-isopropylacrylamide (for example, a copolymerization ratio of N-isopropylacrylamide) is more than 50% by weight).
• Examples of cyclic amides having an N-(meth)acryloyl group include N-acryloylmorpholine, N-acryloylthiomorpholine, N-acryloylpiperidine, N-acryloylpyrrolidine, N-methacryloylmorpholine, N-methacryloylpiperidine, N-methacryloyl Examples include pyrrolidine.
• An example of a polymer containing a cyclic amide having an N-(meth)acryloyl group as a monomer unit is an acryloylmorpholine polymer (PACMO).
• acryloylmorpholine-based polymers include homopolymers of N-acryloylmorpholine (ACMO) and copolymers of ACMO (for example, copolymers in which the copolymerization ratio of ACMO exceeds 50% by weight).
• ACMO N-acryloylmorpholine
• the ratio of the number of moles of ACMO units to the number of moles of all repeating units is usually 50% or more, and 80% or more (for example, 90% or more, typically 95% or more). That is appropriate.
• All repeating units of the water-soluble polymer may be substantially composed of ACMO units.
• the types of the first water-soluble polymer (C1) and the second water-soluble polymer (C2) are not particularly limited, and appropriate types can be selected from among the various water-soluble polymers described above. can be done.
• a polyvinyl alcohol polymer is used as the first water-soluble polymer (C1).
• the substrate surface can be suitably protected during polishing based on the action of the first water-soluble polymer (C1) having VA units.
• Such an action may be, but is not particularly limited to, a protective action on the substrate surface.
• the polyvinyl alcohol-based polymer as the first water-soluble polymer (C1) may be unmodified PVA or modified PVA, and for example, acetalized polyvinyl alcohol is preferably used.
• the details of the polyvinyl alcohol-based polymer as the first water-soluble polymer (C1) are as described above, and redundant explanation will be omitted.
• the second water-soluble polymer (C2) may be a polyvinyl alcohol-based polymer, and has a water-soluble property different from the polyvinyl alcohol-based polymer. It may be a polymer (non-polyvinyl alcohol polymer).
• the first water-soluble polymer (C1) and the second water-soluble polymer (C2) are both polyvinyl alcohol-based polymers, the one with a higher mole ratio (mole ratio) of VA units is water-soluble polymer (C1).
• a polymer containing nitrogen atoms is used as the second water-soluble polymer (C2).
• the substrate surface can be suitably protected during polishing based on the action of the polymer having nitrogen atoms.
• this action is not particularly limited, it is an action based on the adsorption of the second water-soluble polymer (C2) to the silica particles (A), and is based on the action of the first water-soluble polymer (C1). may have different effects.
• the polymer having a nitrogen atom as the second water-soluble polymer (C2) is typically a polymer containing a nitrogen atom-containing repeating unit (N-containing repeating unit), for example, N-(meth)
• N-containing repeating unit for example, N-(meth)
• An acryloyl type polymer is preferably used, a polymer containing a cyclic amide having an N-(meth)acryloyl group as a monomer unit is more preferred, and PACMO is even more preferred.
• the details of the nitrogen atom-containing polymer as the second water-soluble polymer (C2) are as described above, and redundant explanation will be omitted.
• the first water-soluble polymer (C1) may be a polymer having a nitrogen atom, and the polymer having a nitrogen atom is It may be a different water-soluble polymer (non-nitrogen-containing polymer, for example, non-N-(meth)acryloyl type polymer).
• the first water-soluble polymer (C1) and the second water-soluble polymer (C2) are both polymers having nitrogen atoms, the ratio of the number of moles of N-containing repeating units in one polymer molecule (mol The one with a higher ratio) is defined as the second water-soluble polymer (C2).
• the weight average molecular weight (Mw) of the water-soluble polymer (C) is not particularly limited.
• the Mw of the water-soluble polymer (C) may be, for example, approximately 200 ⁇ 10 4 or less, suitably approximately 150 ⁇ 10 4 or less, and preferably approximately 100 ⁇ 10 4 or less from the viewpoint of cleanability etc. However, it may be approximately 50 ⁇ 10 4 or less.
• the Mw of the water-soluble polymer (C) may be, for example, 0.2 ⁇ 10 4 or more, and preferably 0.5 ⁇ 10 4 or more.
• the Mw is suitably 1.0 ⁇ 10 4 or more, and may be 2 ⁇ 10 4 or more, for example, 5 ⁇ 10 4 or more.
• the Mw of the first water-soluble polymer (C1) and the second water-soluble polymer (C2) can also be set within the above range.
• the preferred molecular weight range of the water-soluble polymer (C) may vary depending on the type of polymer used.
• the Mw of the cellulose derivative and the starch derivative can each be approximately 200 ⁇ 10 4 or less, and 150 ⁇ 10 4 or less is appropriate.
• the Mw may be approximately 100 ⁇ 10 4 or less, or approximately 50 ⁇ 10 4 or less (for example, approximately 30 ⁇ 10 4 or less).
• the above Mw is, for example, about 0.2 ⁇ 10 4 or more, suitably about 0.5 ⁇ 10 4 or more, preferably about 1.0 ⁇ It is 10 4 or more, more preferably about 3.0 ⁇ 10 4 or more, still more preferably about 10 ⁇ 10 4 or more, and may be about 20 ⁇ 10 4 or more.
• the Mw of the polyvinyl alcohol polymer can be 100 ⁇ 10 4 or less, and suitably 60 ⁇ 10 4 or less. From the viewpoint of concentration efficiency, etc., the Mw may be 30 ⁇ 10 4 or less, preferably 20 ⁇ 10 4 or less, for example, 10 ⁇ 10 4 or less, 8 ⁇ 10 4 or less, It may be 5 ⁇ 10 4 or less, or 3 ⁇ 10 4 or less. As the Mw of the polyvinyl alcohol polymer decreases, the dispersion stability of the polyvinyl alcohol polymer tends to improve. Further, from the viewpoint of suitably protecting the polished surface and maintaining or improving surface quality, the above Mw may be, for example, 0.2 ⁇ 10 4 or more, and usually 0.5 ⁇ 10 4 or more. preferable.
• the above Mw is suitably 0.8 x 10 4 or more, preferably 1.0 x 10 4 or more, and may be 2 x 10 4 or more, It may be 3 ⁇ 10 4 or more, for example, 4 ⁇ 10 4 or more, or 5 ⁇ 10 4 or more.
• the Mw of a polymer containing a nitrogen atom can be set to 100 ⁇ 10 4 or less, and suitably 70 ⁇ 10 4 or less. From the viewpoint of concentration efficiency, etc., the Mw may be 60 ⁇ 10 4 or less, or 50 ⁇ 10 4 or less. Further, from the viewpoint of maintaining or improving surface quality, the Mw may be, for example, 1.0 ⁇ 10 4 or more, or 10 ⁇ 10 4 or more. In some embodiments, the Mw is suitably 20 ⁇ 10 4 or more, preferably 30 ⁇ 10 4 or more, more preferably 35 ⁇ 10 4 or more, for example, even if it is 40 ⁇ 10 4 or more. good.
• N-(meth)acryloyl type polymer preferably PACMO
• the Mw of the polymer containing oxyalkylene units can be 10 ⁇ 10 4 or less, 5 ⁇ 10 4 or less, 3 ⁇ 10 4 or less, or 2 ⁇ 10 4 or less.
• the Mw may be 0.5 ⁇ 10 4 or more, 0.8 ⁇ 10 4 or more, or 1 ⁇ 10 4 or more.
• the second water-soluble polymer (C2) (for example, nitrogen
• the ratio (Mw2/Mw1) of Mw (Mw2) of the polymer containing atoms is preferably larger than 1.
• a relatively low molecular weight substance is used as the first water-soluble polymer (C1) (for example, a polyvinyl alcohol polymer), and a relatively low molecular weight substance is used as the second water-soluble polymer (C2) (for example, a polymer containing a nitrogen atom).
• the action of the first water-soluble polymer (C1) (for example, the protective action on the substrate) is easily exerted, and the action of the second water-soluble polymer (C2) ( For example, the effect based on adsorption to silica particles (A)) tends to be more effective.
• the ratio (Mw2/Mw1) is 5 or more, more preferably 10 or more, even more preferably 20 or more, may be 30 or more, or may be 40 or more.
• the upper limit of the ratio (Mw2/Mw1) is, for example, 200 or less, suitably about 100 or less, preferably 70 or less, and may be 50 or less.
• Mw of the water-soluble polymer (C) a molecular weight calculated from a value based on aqueous gel permeation chromatography (GPC) (aqueous, polyethylene oxide equivalent) can be adopted.
• GPC gel permeation chromatography
• HLC-8320GPC model name manufactured by Tosoh Corporation. The measurement can be performed, for example, under the following conditions. A similar method is adopted for the embodiments described below.
• nonionic polymers can be preferably employed as the water-soluble polymer (C).
• synthetic polymers can be preferably employed as the water-soluble polymer (C).
• the polishing composition substantially contains a polymer derived from a natural product as the water-soluble polymer (C). It may not be used on a regular basis.
• substantially not used means that the amount of the natural product-derived polymer used is typically 3 parts by weight or less, preferably 1 part by weight, based on 100 parts by weight of the total content of the water-soluble polymer (C). It refers to the following, and includes 0 parts by weight or below the detection limit.
• the content of the water-soluble polymer (C) (a water-soluble polymer containing a first water-soluble polymer (C1) and a second water-soluble polymer (C2))
• the total amount of polymers can be, for example, 0.01 parts by weight or more, based on 100 parts by weight of the silica particles (A), and from the viewpoint of reducing haze, etc., it is suitably 0.1 parts by weight or more.
• the amount is preferably 0.5 parts by weight or more, more preferably 1 part by weight or more, still more preferably 2 parts by weight or more, and may be, for example, 4 parts by weight or more, or 6 parts by weight or more.
• the content of the water-soluble polymer (C) relative to 100 parts by weight of the silica particles (A) may be, for example, 50 parts by weight or less, or 30 parts by weight or less. From the viewpoint of dispersion stability of the polishing composition, in some embodiments, it is appropriate that the content of the water-soluble polymer (C) is 15 parts by weight or less with respect to 100 parts by weight of the silica particles (A). It is preferably 10 parts by weight or less, may be 8 parts by weight or less, or may be 7 parts by weight or less.
• the content of the polyvinyl alcohol polymer in the polishing composition can be, for example, 0.01 part by weight or more with respect to 100 parts by weight of the silica particles (A), and from the viewpoint of haze reduction etc., it is preferably 0.1 part by weight or more.
• the amount is appropriate, preferably 0.5 part by weight or more, more preferably 1 part by weight or more.
• the content of the polyvinyl alcohol polymer based on 100 parts by weight of the silica particles (A) may be, for example, 50 parts by weight or less, or 30 parts by weight or less.
• the content of the polyvinyl alcohol polymer relative to 100 parts by weight of the silica particles (A) is suitably and preferably 15 parts by weight or less. is 10 parts by weight or less, more preferably 5 parts by weight or less, may be 3 parts by weight or less, or may be 2 parts by weight or less.
• the content of the polymer containing nitrogen atoms (two or more types of nitrogen atoms) in the polishing composition may be If a polymer is included, the total amount thereof can be, for example, 0.01 part by weight or more based on 100 parts by weight of the silica particles (A), and from the viewpoint of haze reduction etc.
• the amount is suitably at least 0.5 parts by weight, preferably at least 0.5 parts by weight, may be at least 1 part by weight, may be at least 3 parts by weight, and may be at least 4 parts by weight.
• the content of the polymer containing nitrogen atoms relative to 100 parts by weight of the silica particles (A) may be, for example, 50 parts by weight or less, or 30 parts by weight or less. From the viewpoint of dispersion stability of the polishing composition, etc., in some embodiments, the content of the nitrogen atom-containing polymer relative to 100 parts by weight of the silica particles (A) is preferably 15 parts by weight or less. , preferably 10 parts by weight or less, and may be, for example, 5 parts by weight or less.
• the content of the first water-soluble polymer (C1) (for example, polyvinyl alcohol polymer) in the polishing composition is based on 100 parts by weight of the silica particles (A).
• the amount can be 0.01 part by weight or more, and from the viewpoint of reducing haze, it is appropriate to use 0.1 part by weight or more, preferably 0.5 part by weight or more, more preferably 1 part by weight. That's all.
• the content of the first water-soluble polymer (C1) relative to 100 parts by weight of the silica particles (A) may be, for example, 50 parts by weight or less, or 30 parts by weight or less.
• the content of the first water-soluble polymer (C1) with respect to 100 parts by weight of the silica particles (A) is 15 parts by weight or less. is appropriate, preferably 10 parts by weight or less, more preferably 5 parts by weight or less, may be 3 parts by weight or less, and may be 2 parts by weight or less.
• the content of the second water-soluble polymer (C2) (for example, a polymer containing a nitrogen atom) in the polishing composition is 100% by weight of the silica particles (A).
• the amount can be 0.01 part by weight or more, and from the viewpoint of reducing haze, it is appropriate to use 0.1 part by weight or more, preferably 0.5 part by weight or more, and 1 part by weight. It may be at least 3 parts by weight, or at least 4 parts by weight.
• the content of the second water-soluble polymer (C2) relative to 100 parts by weight of the silica particles (A) may be, for example, 50 parts by weight or less, or 30 parts by weight or less.
• the content of the second water-soluble polymer (C2) with respect to 100 parts by weight of the silica particles (A) is 15 parts by weight or less. is suitable, preferably 10 parts by weight or less, and may be, for example, 5 parts by weight or less.
• the ratio of the first water-soluble polymer (C1) (for example, a polyvinyl alcohol polymer) and the second water-soluble polymer (C2) (for example, a polymer containing a nitrogen atom) is not particularly limited.
• the ratio (C2/C1) of the content of the second water-soluble polymer (C2) to the content of the first water-soluble polymer (C1) is suitably 0.1 or more on a weight basis.
• the ratio (C2/C1) is 0.3 or more, and 0.5 or more. It may be 1.0 or more (for example, more than 1.0), 1.5 or more, 2.0 or more, 2.5 or more, or 3.0 or more.
• the ratio (C2/C1) is suitably 20 or less on a weight basis, and is preferably 10 or less, more preferably is 5.0 or less, may be 3.5 or less, may be 2.5 or less, may be 1.5 or less, or may be 1.0 or less (for example, less than 1.0).
• the first water-soluble polymer (C1) e.g., polyvinyl alcohol polymer
• the second water-soluble polymer (C2) e.g., containing a nitrogen atom
• the polishing composition disclosed herein includes, as the water-soluble polymer (C), a first water-soluble polymer (C1) and a second water-soluble polymer (C2); It may contain one or more arbitrary water-soluble polymers (C3) having a chemical structure different from the polymer (C1) and the second water-soluble polymer (C2).
• Such optional water-soluble polymer (C3) can be selected from the various water-soluble polymers mentioned above.
• the optional water-soluble polymer (C3) may be a polyvinyl polymer, but in that case, the molar ratio of VA units in the optional water-soluble polymer (C3) is lower than that of the first water-soluble polymer (C1). low.
• the optional water-soluble polymer (C3) may be a polymer having a nitrogen atom, but in that case, the molar ratio of the N-containing repeating units in the optional water-soluble polymer (C3) is Lower than polymer (C2).
• the content ratio of the optional water-soluble polymer (C3) to the entire water-soluble polymer (C) contained in the polishing composition is particularly limited.
• polishing composition does not substantially contain any water-soluble polymer (C3).
• the content and ratio (C2/C1) of the water-soluble polymers (C) (C1) (C2), polyvinyl alcohol polymers, and nitrogen atom-containing polymers are, for example, silicon wafers. It can be preferably employed in polishing compositions, and is particularly suitable for final polishing compositions for silicon wafers.
• the polishing composition disclosed herein contains an inorganic acid alkali metal salt (D).
• the inorganic acid alkali metal salt (D) refers to a salt of an inorganic acid as an anion and an alkali metal as a cation.
• the inorganic acid alkali metal salt (D) does not include an alkali metal carbonate.
• a composition containing silica particles (A), a basic compound (B), a first water-soluble polymer (C1), and a second water-soluble polymer (C2) contains an inorganic acid alkali metal different from the alkali metal carbonate.
• the high polished surface quality e.g., low haze value
• polishing rate can be improved.
• the inorganic acid alkali metal salt (D) present in the polishing composition the surface to be polished can be suitably protected by the first water-soluble polymer (C1) and the second water-soluble polymer (C2). This is thought to be because alkali etching is effectively promoted. Note that the technology disclosed herein is not limited to the above interpretation.
• the inorganic acid alkali metal salt (D) can be used alone or in combination of two or more.
• Examples of the inorganic acid contained in the inorganic acid alkali metal salt (D) include hydrohalic acid (e.g., hydrochloric acid, hydrobromic acid, hydroiodic acid, and hydrofluoric acid), nitric acid, sulfuric acid, sulfite, and thiosulfuric acid. Examples include sulfuric acid, silicic acid, boric acid, phosphoric acid, phosphonic acid, and phosphinic acid.
• the inorganic acid alkali metal salt (D) is preferably a salt of nitric acid, sulfuric acid or phosphoric acid, more preferably a salt of nitric acid or sulfuric acid, and particularly preferably an alkali metal nitrate.
• the alkali metal contained in the inorganic acid alkali metal salt (D) is typically one of lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), or It is preferable to include two or more types. Among these, Li, Na, and K are preferred. In other words, inorganic acid lithium salts, inorganic acid sodium salts, and inorganic acid potassium salts are preferred.
• Examples of inorganic acid alkali metal salts (D) include chlorides such as lithium chloride, sodium chloride, and potassium chloride; bromides such as lithium bromide, sodium bromide, and potassium bromide; lithium fluoride, sodium fluoride, Fluorides such as potassium fluoride; Nitrates such as lithium nitrate, sodium nitrate, potassium nitrate; Sulfates such as lithium sulfate, sodium sulfate, potassium sulfate; Sulfites such as lithium sulfite, sodium sulfite, potassium sulfite; Lithium hydrogen sulfite, sulfurous acid Bisulfites such as sodium hydrogen and potassium hydrogen sulfite; thiosulfates such as lithium thiosulfate, sodium thiosulfate, and potassium thiosulfate; silicates such as lithium silicate, sodium silicate, and potassium silicate; lithium borate; Examples include borates such as sodium borate; and the
• the content of the inorganic acid alkali metal salt (D) can be, for example, 0.001 parts by weight or more based on 100 parts by weight of the silica particles (A), and can improve the polishing rate. From this point of view, 0.01 parts by weight or more is appropriate, preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more, still more preferably 1.0 parts by weight or more, and 1.5 parts by weight. It may be more than that. Further, the content of the inorganic acid alkali metal salt (D) with respect to 100 parts by weight of the silica particles (A) can be, for example, 50 parts by weight or less to maintain or improve surface quality (for example, maintain haze or reduce haze). From the viewpoint of the The following may be used.
• the content of the inorganic acid alkali metal salt (D) is determined by the amount of the water-soluble polymer (C) contained in the polishing composition (the amount of the first water-soluble polymer (C1) and the second water-soluble polymer). It can also be specified by the relative relationship with the total amount of water-soluble polymers containing the molecule (C2). For example, in some embodiments, the ratio (D/C) of the content of the inorganic acid alkali metal salt (D) to the content of the water-soluble polymer (C) in the polishing composition is 0.01 on a weight basis.
• the inorganic acid alkali metal salt is preferably 0.1 or more, more preferably 0.2 or more, and may be 0.3 or more.
• the ratio (D/C) is, for example, 30 or less on a weight basis, preferably 10 or less, more preferably 3 or less, may be 1 or less, or may be 0.5 or less.
• the ratio (D/C2) of the content of the inorganic acid alkali metal salt (D) to the content of the second water-soluble polymer (C2) is not particularly limited.
• the ratio (D/C2) is suitably 0.01 or more on a weight basis, preferably 0.1 or more, more preferably 0.2 or more, and 0.3 or more. There may be.
• the above ratio (D/C2) is suitably 100 or less on a weight basis, preferably 10 or less, more preferably 7 or less, may be 5 or less, may be 3 or less, and may be 1 or less. (for example, less than 1), or 0.5 or less.
• polishing rate and surface quality can be better balanced.
• the amount of the inorganic acid alkali metal salt (D) relatively to the amount of the second water-soluble polymer (C2) (for example, a polymer having a nitrogen atom)
• the effect of improving the polishing rate can be easily obtained.
• the second water-soluble polymer (C2) is made of silica particles ( It is thought that it adsorbs well to A), and as a result, both the polishing rate and high surface quality are achieved. Note that the technology disclosed herein is not limited to the above interpretation.
• the content of the inorganic acid alkali metal salt (D) is the same as the amount of the surfactant (E) contained in the polishing composition. It can also be specified by the relative relationship between For example, in some embodiments, the ratio (D/E) of the content of the inorganic acid alkali metal salt (D) to the content of the surfactant (E) in the polishing composition is, for example, 0.1 on a weight basis. From the viewpoint of effectively exhibiting the effect of improving the polishing rate by the inorganic acid alkali metal salt (D), it is preferably 1 or more, more preferably 1.5 or more, and may be 3 or more.
• the ratio (D/E) is, for example, 100 or less, preferably 30 or less, more preferably 15 or less, may be 10 or less, or may be 5 or less on a weight basis.
• the content of the inorganic acid alkali metal salt (D) can be preferably employed, for example, in a silicon wafer polishing composition, and is particularly suitable for a silicon wafer final polishing composition. .
• the polishing composition preferably contains at least one surfactant (E).
• the surfactant (E) By including the surfactant (E) in the polishing composition, haze on the polished surface after polishing can be better reduced.
• a more excellent haze reduction effect can be realized.
• an inorganic acid alkali metal salt (D) in a composition containing two or more water-soluble polymers (C) and a surfactant (E) as described above it is possible to improve the polishing rate while obtaining an excellent haze reduction effect.
• any of anionic, cationic, nonionic, and amphoteric surfactants can be used.
• anionic or nonionic surfactants can be preferably employed.
• nonionic surfactants are more preferred.
• oxyalkylene polymers such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol; polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, polyoxyethylene fatty acid ester, polyoxyethylene glyceryl ether fatty acid Polyoxyalkylene derivatives (e.g.
• polyoxyalkylene adducts such as esters and polyoxyethylene sorbitan fatty acid esters; copolymers of multiple types of oxyalkylenes (e.g. diblock copolymers, triblock copolymers, Nonionic surfactants such as random copolymers, alternating copolymers);
• the surfactants (E) can be used alone or in combination of two or more.
• nonionic surfactants include block copolymers (diblock type copolymers, PEO (polyethylene oxide)-PPO (polypropylene oxide)-PEO type) of ethylene oxide (EO) and propylene oxide (PO).
• block copolymers diblock type copolymers, PEO (polyethylene oxide)-PPO (polypropylene oxide)-PEO type) of ethylene oxide (EO) and propylene oxide (PO).
• preferred surfactants include block copolymers of EO and PO (particularly PEO-PPO-PEO type triblock copolymers), random copolymers of EO and PO, and polyoxyethylene alkyl ethers (for example, polyoxyethylene decyl ether) can be mentioned.
• polyoxyethylene alkyl ether one having an EO addition mole number of about 1 to 10 (for example, about 3 to 8) can be preferably employed.
• the polishing composition includes, as the surfactant (E), a first surfactant (E1) and a second surfactant (E2) different from the first surfactant (E1). including.
• the types of the first surfactant (E1) and the second surfactant (E2) are not particularly limited, and the various surfactants described above may be used.
• the first surfactant (E1) is a polyoxyethylene alkyl ether
• the second surfactant (E2) is a block copolymer of EO and PO (e.g., PEO -PPO-PEO type triblock copolymers) can be used.
• EO and PO e.g., PEO -PPO-PEO type triblock copolymers
• a first surfactant (E1) e.g. polyoxyethylene alkyl ether
• a second surfactant (E2) e.g. a block copolymer of EO and PO
• the ratio of the content of the first surfactant (E1) to the content of the second surfactant (E2) (E1/E2) is suitably 0.1 or more on a weight basis; From the viewpoint of effectively exhibiting the effect of using the activator (E1), it is preferably 0.3 or more, more preferably 0.5 or more, even more preferably 1 or more (for example, more than 1), and 1.5 or more. There may be.
• the above ratio (E1/E2) is suitably 20 or less on a weight basis, and from the viewpoint of effectively exerting the effect of using the second surfactant (E2), it is preferably 10 or less, and more It is preferably 5 or less, and may be 3 or less.
• the first surfactant (E1) for example, polyoxyethylene alkyl ether
• the second surfactant (E2) for example, EO and PO
• the effect of block copolymers tends to be exerted favorably, and high surface quality tends to be obtained.
• the molecular weight of the surfactant (E) is, for example, less than 5,000, preferably 4,500 or less from the viewpoint of filterability, washability, etc., and may be, for example, less than 4,000.
• the molecular weight of the surfactant (E) is usually suitably 200 or more from the viewpoint of surfactant ability, etc., and 250 or more (for example, 300 or more) from the viewpoint of haze reduction effect, etc. preferable.
• the more preferable range of the molecular weight of the surfactant (E) may vary depending on the type of the surfactant.
• polyoxyethylene alkyl ether when polyoxyethylene alkyl ether is used as the surfactant (E), its molecular weight is preferably less than 2,000, more preferably 1,900 or less (for example, less than 1,800), and preferably 1,500 or less. is more preferable, and may be 1000 or less (for example, 500 or less).
• a block copolymer of EO and PO when used as the surfactant (E), its weight average molecular weight may be, for example, 500 or more, 1000 or more, and even 1500 or more. The number may be 2000 or more, or even 2500 or more.
• the molecular weight of the surfactant (E) the molecular weight calculated from the chemical formula may be adopted, or the weight average molecular weight value determined by GPC (aqueous, polyethylene glycol equivalent) may be adopted.
• GPC aqueous, polyethylene glycol equivalent
• the content of the surfactant (E) is usually determined from the silica particles (A) from the viewpoint of cleaning properties.
• the content of the surfactant (E) is suitably 0.001 parts by weight or more, and 0.01 parts by weight or more. It is preferably at least 0.1 parts by weight, more preferably at least 0.5 parts by weight.
• the water (F) used preferably has a total content of transition metal ions of 100 ppb or less, for example, in order to avoid as much as possible the effects of other components contained in the polishing composition.
• the purity of water (F) can be increased by removing impurity ions using an ion exchange resin, removing foreign substances using a filter, distilling, and the like.
• the polishing composition disclosed herein may further contain an organic solvent (lower alcohol, lower ketone, etc.) that can be uniformly mixed with water (F), if necessary. It is preferable that 90% by volume or more of the solvent contained in the polishing composition is water (F), and more preferably 95% by volume or more (for example, 99 to 100% by volume) is water (F).
• an organic solvent lower alcohol, lower ketone, etc.
• the polishing composition disclosed herein may contain organic acids, organic acid salts, inorganic acids, and inorganic acid salts as components other than the above (A) to (F), as long as the effects of the present invention are not significantly impaired. If necessary, it further contains known additives that can be used in polishing compositions (for example, polishing compositions used in the final polishing process of silicon wafers), such as chelating agents, preservatives, and fungicides. It's okay.
• organic acids and their salts, and the inorganic acids and their salts can be used singly or in combination of two or more.
• organic acids include fatty acids such as formic acid, acetic acid, and propionic acid, aromatic carboxylic acids such as benzoic acid and phthalic acid, itaconic acid, citric acid, oxalic acid, tartaric acid, malic acid, maleic acid, fumaric acid, and succinic acid.
• organic acids examples include organic phosphonic acids such as acid (PBTC).
• organic acid salts include alkali metal salts (sodium salts, potassium salts, etc.) and ammonium salts of organic acids.
• inorganic acids examples include hydrochloric acid, phosphoric acid, sulfuric acid, phosphonic acid, nitric acid, phosphinic acid, boric acid, carbonic acid, and the like.
• inorganic acid salts include inorganic acid salts other than inorganic acid alkali metal salts (D), such as alkaline earth metal salts of inorganic acids, ammonium salts of inorganic acids, and poor metal salts of inorganic acids (for example, aluminum salts of inorganic acids). , transition metal salts of inorganic acids (eg, zirconium salts of inorganic acids).
• the above chelating agents may be used alone or in combination of two or more.
• the chelating agent include aminocarboxylic acid chelating agents and organic phosphonic acid chelating agents.
• Suitable examples of chelating agents include, for example, ethylenediaminetetrakis (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), and diethylenetriaminepentaacetic acid.
• Examples of the above-mentioned preservatives and antifungal agents include isothiazoline compounds, paraoxybenzoic acid esters, phenoxyethanol, and the like.
• the polishing composition disclosed herein does not substantially contain an oxidizing agent.
• an oxidizing agent is contained in a polishing composition
• the polishing composition when the polishing composition is supplied to a substrate (for example, a silicon wafer), the surface of the substrate is oxidized to form an oxide film, which reduces the polishing rate. This is because there is a possibility that the value may decrease.
• Specific examples of the oxidizing agent herein include hydrogen peroxide (H 2 O 2 ), sodium persulfate, ammonium persulfate, sodium dichloroisocyanurate, and the like. Note that the term "the polishing composition does not substantially contain an oxidizing agent" means that the polishing composition does not contain an oxidizing agent, at least intentionally.
• the molar concentration of the oxidizing agent in the polishing composition is 0.001 mol/L or less, preferably 0.0005 mol/L or less, more preferably 0.0001 mol/L or less, depending on the raw materials, manufacturing method, etc.
• the pH of the polishing composition disclosed herein is not particularly limited, and an appropriate pH may be adopted depending on the substrate and the like.
• the pH of the polishing composition is suitably 8.0 or higher, preferably 8.5 or higher, and more preferably 9.0 or higher.
• the pH of the polishing composition increases, the polishing rate tends to improve.
• the pH of the polishing composition is usually 12.0 or less, and 11.0 or less. It is preferably at most 10.8, more preferably at most 10.5, even more preferably at most 10.5.
• the pH of the polishing composition is measured using a pH meter (for example, a glass electrode hydrogen ion concentration indicator manufactured by Horiba, Ltd. (model number F-72)) and a standard buffer solution ( Phthalate pH buffer pH: 4.01 (25°C), Neutral phosphate pH buffer pH: 6.86 (25°C), Carbonate pH buffer pH: 10.01 (25°C))
• a pH meter for example, a glass electrode hydrogen ion concentration indicator manufactured by Horiba, Ltd. (model number F-72)
• a standard buffer solution Phthalate pH buffer pH: 4.01 (25°C), Neutral phosphate pH buffer pH: 6.86 (25°C), Carbonate pH buffer pH: 10.01 (25°C)
• the glass electrode can be placed in the composition to be measured, and the value can be determined by measuring the value after 2 minutes or more have passed and the value has stabilized.
• the polishing composition disclosed herein is supplied onto the surface of a substrate in the form of a polishing liquid and used for polishing the substrate.
• the polishing liquid may be prepared by diluting (typically diluting with water) any of the polishing compositions disclosed herein, for example.
• the polishing composition may be used as it is as a polishing liquid.
• Another example of a polishing liquid containing the polishing composition disclosed herein is a polishing liquid prepared by adjusting the pH of the composition.
• the content of silica particles (A) in the polishing composition (polishing liquid) is not particularly limited, and in some embodiments is, for example, 0.01% by weight or more, preferably 0.05% by weight or more. , more preferably 0.10% by weight or more, still more preferably 0.15% by weight or more. Higher polishing rates can be achieved by increasing the silica particle (A) content.
• the content is suitably 10% by weight or less, preferably 7% by weight or less, more preferably 5% by weight or less, still more preferably 2% by weight or less, for example 1% by weight or less. % or less, 0.5% by weight or less, or 0.4% by weight or less. This makes it possible to achieve a higher quality surface.
• the content of the basic compound (B) in the polishing composition (polishing liquid) is not particularly limited. From the viewpoint of improving the polishing rate, it is usually appropriate to set the above content to 0.0005% by weight or more, preferably 0.001% by weight or more, and 0.003% by weight or more. is even more preferable. In addition, from the viewpoint of improving surface quality (for example, reducing haze), the above content is suitably less than 0.1% by weight, preferably less than 0.05% by weight, and 0.03% by weight. % (for example, less than 0.025% by weight, and even less than 0.01% by weight).
• the content of the first water-soluble polymer (C1) (for example, polyvinyl alcohol polymer) in the polishing composition (polishing liquid) is not particularly limited, and in some embodiments, from the viewpoint of improving surface quality, etc. For example, it may be 0.0001% by weight or more, usually 0.0005% by weight or more, preferably 0.001% by weight or more, and for example 0.002% by weight or more. good.
• the upper limit of the content of the first water-soluble polymer (C1) is not particularly limited, and can be, for example, 0.05% by weight or less.
• the content of the first water-soluble polymer (C1) is preferably 0.03% by weight or less, more preferably 0.03% by weight or less, from the viewpoint of stability in the concentrate stage, polishing rate, cleanability, etc. It is preferably 0.015% by weight or less, more preferably 0.01% by weight or less.
• the technology disclosed herein provides a polishing composition (with a content of the first water-soluble polymer (C1) of, for example, 0.008% by weight or less, 0.006% by weight or less, or 0.004% by weight or less). It can be preferably carried out using a polishing liquid).
• the content of the second water-soluble polymer (C2) (for example, a polymer containing a nitrogen atom) in the polishing composition (polishing liquid) is not particularly limited, and from the viewpoint of improving surface quality, etc.
• the content may be 0.0001% by weight or more, usually 0.0005% by weight or more, preferably 0.001% by weight or more, and 0.002% by weight or more.
• the content may be 0.003% by weight or more, or may be 0.005% by weight or more.
• the upper limit of the content of the second water-soluble polymer (C2) is not particularly limited, and can be, for example, 0.1% by weight or less.
• the content of the second water-soluble polymer (C2) is preferably 0.05% by weight or less, more preferably 0.05% by weight or less, from the viewpoint of stability in the concentrate stage, polishing rate, cleanability, etc. It is preferably 0.02% by weight or less, more preferably 0.01% by weight or less.
• the total content of the first water-soluble polymer (C1) and the second water-soluble polymer (C2) in the polishing composition (polishing liquid) is not particularly limited, and in some embodiments may be, for example, 0. 0001% by weight or more. From the viewpoint of haze reduction etc., the above total content is preferably 0.0005% by weight or more, more preferably 0.001% by weight or more, even more preferably 0.002% by weight or more, for example 0.005% by weight. It may be more than that. In addition, from the viewpoint of polishing rate, etc., the above content is preferably 0.2% by weight or less, more preferably 0.1% by weight or less, and 0.05% by weight or less (for example, 0.02% by weight or less).
• polishing composition contains an optional water-soluble polymer (C3) in addition to the first water-soluble polymer (C1) and the second water-soluble polymer (C2)
• polishing composition contains an optional water-soluble polymer (C3) in addition to the first water-soluble polymer (C1) and the second water-soluble polymer (C2)
• the total content of the water-soluble polymer (C) contained in the product (polishing liquid) can be set from the above range.
• the content of the inorganic acid alkali metal salt (D) in the polishing composition (polishing liquid) is not particularly limited, and can be set so that the effects of its use are appropriately exhibited.
• the content of the inorganic acid alkali metal salt (D) can be, for example, 0.0001% by weight or more, and from the viewpoint of improving the polishing rate, 0.0005% by weight or more is suitable, It is preferably 0.001% by weight or more, may be 0.003% by weight or more, may be 0.005% by weight or more, may be 0.007% by weight or more, and may be 0.010% by weight or more.
• the content of the inorganic acid alkali metal salt (D) may be, for example, 5% by weight or less, 1% by weight or less, or 0.3% by weight or less.
• the content of the inorganic acid alkali metal salt (D) is preferably 0.1% by weight or less, more preferably 0.05% by weight.
• the content is more preferably 0.03% by weight or less, may be 0.01% by weight or less, and may be 0.005% by weight or less.
• the content of the surfactant (E) in the polishing composition (polishing liquid) is within a range that does not significantly impede the effects of the present invention.
• the content of the surfactant (E) can be set to, for example, 0.00001% by weight or more from the viewpoint of detergency and the like. From the viewpoint of reducing haze, etc., the content is preferably 0.0001% by weight or more, more preferably 0.0005% by weight or more, and still more preferably 0.001% by weight or more.
• the above content is preferably 0.1% by weight or less, more preferably 0.01% by weight or less, and 0.005% by weight or less (for example, 0.002% by weight or less). % or less, more preferably 0.0015% by weight or less).
• polishing liquid can be preferably employed, for example, in a silicon wafer polishing composition, and particularly in a silicon wafer final polishing composition. suitable.
• the polishing composition disclosed herein may be in a concentrated form (that is, in the form of a concentrated polishing liquid) before being supplied to the substrate.
• the polishing composition in such a concentrated form is advantageous from the viewpoint of convenience and cost reduction during manufacturing, distribution, storage, and the like.
• the concentration ratio is not particularly limited, and can be, for example, about 2 times to 100 times in terms of volume, and usually about 5 times to 50 times (for example, about 10 times to 40 times) is appropriate.
• Such a concentrated liquid can be diluted at a desired timing to prepare a polishing liquid (working slurry), and the polishing liquid can be used in a manner of supplying the polishing liquid to the substrate.
• the dilution can be performed, for example, by adding water to the concentrate and mixing.
• the content of silica particles (A) in the concentrated liquid can be, for example, 25% by weight or less.
• the content of the silica particles (A) is usually preferably 20% by weight or less, more preferably 15% by weight or less.
• the content of silica particles (A) may be 10% by weight or less, or may be 5% by weight or less.
• the content of silica particles (A) in the concentrated liquid can be, for example, 0.1% by weight or more, and preferably 0.1% by weight or more. The content is .5% by weight or more, more preferably 0.7% by weight or more, even more preferably 1% by weight or more.
• the content of the basic compound (B) in the concentrate is, for example, suitably 0.01% by weight or more, preferably 0.02% by weight or more, More preferably, the content is 0.06% by weight or more. Further, in some embodiments, the content of the basic compound (B) is suitably less than 2.0% by weight, preferably less than 1.0% by weight, and 0.5% by weight. % (for example, less than 0.3% by weight).
• the total content of the first water-soluble polymer (C1) and the second water-soluble polymer (C2) in the concentrate can be, for example, 0.001% by weight or more,
• the content is preferably 0.01% by weight or more, more preferably 0.02% by weight or more, even more preferably 0.04% by weight or more, and may be, for example, 0.1% by weight or more.
• the total content is preferably 5% by weight or less, more preferably 2.0% by weight or less, and even more preferably 1.0% by weight or less (for example, 0.5% by weight or less). preferable.
• the polishing composition (concentrate) contains an arbitrary water-soluble polymer (C3) in addition to the first water-soluble polymer (C1) and the second water-soluble polymer (C2), the polishing composition (concentrate)
• the total content of the water-soluble polymer (C) contained can be set from the above range.
• the content of the inorganic acid alkali metal salt (D) in the concentrate can be, for example, 0.001% by weight or more, suitably 0.005% by weight or more, and preferably The content is 0.01% by weight or more, more preferably 0.03% by weight or more, may be 0.05% by weight or more, and may be 0.1% by weight or more.
• the content of the inorganic acid alkali metal salt (D) is, for example, 10% by weight or less, suitably 3% by weight or less, preferably 1% by weight or less, and 0.3% by weight or less. The content may be 0.1% by weight or less.
• the content of the surfactant (E) in the concentrate can be, for example, 0.0001% by weight or more, and preferably It is 0.001% by weight or more, more preferably 0.01% by weight or more. Further, the content is preferably 1% by weight or less, more preferably 0.1% by weight or less, and even more preferably 0.05% by weight or less.
• the polishing composition used in the technique disclosed herein may be of a single-component type or a multi-component type such as a two-component type.
• part A containing at least silica particles (A) among the constituent components of the polishing composition and part B containing at least a portion of the remaining components are mixed, and these are mixed at appropriate timing as necessary.
• the polishing liquid may be prepared by diluting the polishing liquid.
• each component constituting the polishing composition may be mixed using a well-known mixing device such as a blade stirrer, an ultrasonic disperser, or a homomixer.
• a well-known mixing device such as a blade stirrer, an ultrasonic disperser, or a homomixer.
• the manner in which these components are mixed is not particularly limited, and for example, all the components may be mixed at once, or may be mixed in an appropriately set order.
• the polishing composition disclosed herein can be applied to polishing substrates having various materials and shapes.
• the material of the substrate is, for example, a silicon material, a metal or semimetal such as aluminum, nickel, tungsten, copper, tantalum, titanium, stainless steel, or an alloy thereof; a glassy material such as quartz glass, aluminosilicate glass, glassy carbon, etc.
• 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
• resin materials such as polyimide resin; etc.
• the substrate may be made of a plurality of these materials.
• the shape of the substrate is not particularly limited.
• the polishing composition disclosed herein can be applied, for example, to polishing a flat substrate such as a plate or polyhedron, or to polishing an edge of a substrate (for example, polishing a wa
• the polishing composition disclosed herein can be preferably used for polishing a surface made of silicon material.
• silicon materials include silicon single crystal, amorphous silicon, polysilicon, and the like.
• the polishing composition disclosed herein can be particularly preferably used for polishing surfaces made of silicon single crystals (for example, polishing silicon wafers).
• the polishing composition disclosed herein can be preferably applied to a polishing process of a substrate (for example, a silicon wafer).
• a substrate for example, a silicon wafer.
• the substrate Prior to the polishing step using the polishing composition disclosed herein, the substrate may be subjected to general treatments that can be applied to the substrate in a step upstream of the polishing step, such as lapping or etching.
• the polishing composition disclosed herein is effectively used in the finishing process of a substrate (for example, a silicon wafer) or in the polishing process immediately before the finishing process, and is particularly preferably used in the final polishing process.
• the final polishing step refers to the final polishing step in the manufacturing process of the target product (that is, a step in which no further polishing is performed after that step).
• the polishing composition disclosed herein also includes a polishing step upstream of the final polishing (refers to a preliminary polishing step between the rough polishing step and the final polishing step, typically including at least a primary polishing step). , and may further include secondary, tertiary, etc. polishing steps), for example, it may be used in a polishing step performed immediately before final polishing.
• the polishing composition disclosed herein can be used, for example, in polishing (typically final polishing or polishing immediately before polishing) of silicon wafers that have been prepared in an upstream process to have a surface roughness of 0.01 nm to 100 nm. is effective. Application to finishing polishing is particularly preferred.
• the surface roughness Ra of the substrate can be measured using, for example, a laser scanning surface roughness meter "TMS-3000WRC" manufactured by Schmitt Measurement System Inc.
• the polishing composition disclosed herein can be used for polishing a substrate, for example, in a manner including the following operations.
• a preferred embodiment of a method for polishing a silicon wafer as a substrate using the polishing composition disclosed herein will be described. That is, a polishing liquid containing one of the polishing compositions disclosed herein is prepared.
• Preparing the polishing liquid may include preparing the polishing liquid by subjecting the polishing composition to operations such as concentration adjustment (for example, dilution) and pH adjustment.
• concentration adjustment for example, dilution
• pH adjustment for example, a polishing liquid
• the polishing composition may be used as it is as a polishing liquid.
• the polishing liquid is supplied to the substrate and polished by a conventional method.
• a silicon wafer typically the silicon wafer that has undergone the lapping process is set in a general polishing device, and a polishing liquid is applied to the surface to be polished of the silicon wafer through the polishing pad of the polishing device.
• a polishing pad is pressed against the surface of the silicon wafer to be polished, and the two are moved relative to each other (for example, rotated). After this polishing step, polishing of the substrate is completed.
• the polishing pad used in the above polishing step is not particularly limited.
• a polishing pad of foamed polyurethane type, nonwoven fabric type, suede type, etc. can be used.
• Each polishing pad may contain abrasive grains or may not contain abrasive grains.
• a polishing pad that does not contain abrasive grains is preferably used.
• a substrate polished using the polishing composition disclosed herein is typically cleaned. Cleaning can be performed using a suitable cleaning solution.
• the cleaning solution used is not particularly limited, and for example, SC-1 cleaning solution (ammonium hydroxide (NH 4 OH), hydrogen peroxide (H 2 O 2 ), and water (H 2 O), which is common in the field of semiconductors, etc.) is used.
• a mixed solution of HCl, H 2 O 2 and H 2 O), an SC-2 cleaning solution (a mixed solution of HCl, H 2 O 2 and H 2 O), etc. can be used.
• the temperature of the cleaning liquid can range from, for example, room temperature (typically about 15°C to 25°C) to about 90°C. From the viewpoint of improving the cleaning effect, a cleaning solution having a temperature of about 50° C. to 85° C. can be preferably used.
• the technology disclosed herein includes a method for manufacturing a polished product (for example, a method for manufacturing a silicon wafer) including a polishing step (preferably final polishing) using any of the polishing methods described above, and a method for manufacturing a polished product using the method. Provision of manufactured abrasive objects (eg, silicon wafers) may be included.
• Example 1 Silica particles (A), basic compound (B), water-soluble polymer (C), inorganic acid alkali metal salt (D), surfactant (E) and deionized water (F) were mixed. Concentrates of polishing compositions according to Nos. 1 to 11 were prepared. In addition, silica particles (A), a basic compound (B), a water-soluble polymer (C), a surfactant (E), and deionized water (F) were mixed to prepare a polishing solution according to Comparative Examples 1 to 3. A concentrated solution of the composition was prepared.
• the water-soluble polymer (C) includes a first water-soluble polymer (C1) (acetalized polyvinyl alcohol (ac-PVA) with a Mw of about 1.0 ⁇ 10 4 ) and a second water-soluble polymer ( C2) (polyacryloylmorpholine (PACMO) with Mw of about 4.7 ⁇ 10 5 ) was used.
• ac-PVA acetalized polyvinyl alcohol
• C2 polyacryloylmorpholine
• D the types shown inorganic acid alkali metal salt
• surfactant (E) polyoxyethylene (5 moles of ethylene oxide added) decyl ether (C10EO5) having a molecular weight of 378 and a PEO-PPO-PEO block copolymer (PEO-PPO-PEO) having an Mw of 3000 are used. )It was used.
• polishing composition By diluting the obtained polishing composition concentrate with deionized water to a volume ratio of 20 times, 0.169% of the silica particles (A), 0.005% of the basic compound (B), and the first 0.0025% of the water-soluble polymer (C1), the content of the second water-soluble polymer (C2) shown in Table 1, the content of the inorganic acid alkali metal salt (D) shown in Table 1, the first The polishing composition according to each example (polishing liquid) was obtained. In Table 1, "-" indicates that the polishing composition does not contain that component.
• a commercially available silicon single crystal wafer (conductivity type: P type, crystal orientation: ⁇ 100>, COP (Crystal Originated Particle: crystal defect) free) with a diameter of 300 mm that had been lapped and etched was prepared under the following polishing conditions 1.
• a polished silicon wafer was prepared.
• Preliminary polishing was performed using a polishing solution containing 1.0% abrasive grains (colloidal silica with an average primary particle size of 35 nm) and 0.068% potassium hydroxide in deionized water.
• Polishing device Single-fed polishing device model “PNX-332B” manufactured by Okamoto Machine Tools Co., Ltd. Polishing load: 20kPa Rotation speed of surface plate: 20 rpm Head (carrier) rotation speed: 20 rpm Polishing pad: Manufactured by Nitta DuPont, product name “SUBA400” Polishing liquid supply rate: 1L/min Polishing liquid temperature: 20°C Surface plate cooling water temperature: 20°C Polishing time: 3min
• the silicon wafer after the preliminary polishing was polished under the following polishing conditions 2.
• Polishing device Single-fed polishing device model “PNX-332B” manufactured by Okamoto Machine Tools Co., Ltd. Polishing load: 10kPa Rotation speed of surface plate: 50 rpm Head (carrier) rotation speed: 50 rpm Polishing pad: Manufactured by Fujibo Ehime, product name: “POLYPAS275NX” Polishing liquid supply rate: 1.5L/min Polishing liquid temperature: 20°C Surface plate cooling water temperature: 20°C Polishing time: 4min
• SC-1 cleaning More specifically, a first cleaning tank equipped with an ultrasonic oscillator is prepared, the cleaning solution is stored in the first cleaning tank and maintained at 70° C., and the polished silicon wafer is immersed in the cleaning tank for 6 minutes. did. Thereafter, the silicon wafer was immersed in a second cleaning tank containing ultrapure water at 25°C for 15 minutes, then again in the first cleaning tank for 6 minutes, and in the second cleaning tank for 16 minutes, and then dried.
• ⁇ Haze measurement> The haze (ppm) of the cleaned silicon wafer surface was measured in DWO mode using a wafer inspection device manufactured by KLA-Tencor, trade name "Surfscan SP5". The obtained results were converted into a relative value (haze) with the haze value for Comparative Example 1 as 100%. The smaller the haze value, the higher the haze improvement effect. If the haze value is 105% or less, it is evaluated that high surface quality was maintained.
• a silicon wafer with a diameter of 200 mm (conductivity type: P type, crystal orientation: ⁇ 100>, COP free) was prepared as the object to be polished, and the oxide film was removed by immersing it in an HF aqueous solution (HF concentration: 2%) for 60 seconds. Then, polishing was performed under the following polishing conditions 3 using the polishing composition according to each example as a polishing liquid.
• Polishing device Single wafer polishing device model “PNX-322” manufactured by Okamoto Machine Tools Co., Ltd. Polishing load: 10kPa Rotation speed of surface plate: 30 rpm Head (carrier) rotation speed: 30 rpm Polishing pad: Manufactured by Fujibo Ehime, product name: “POLYPAS275NX” Polishing liquid supply rate: 400mL/min Polishing liquid temperature: 20°C Surface plate cooling water temperature: 20°C Polishing time: 10min
• silica particles (A), basic compound (B), first water-soluble polymer (C1), second water-soluble polymer (C2) and inorganic acid alkali metal salt (D ) As shown in Table 1, silica particles (A), basic compound (B), first water-soluble polymer (C1), second water-soluble polymer (C2) and inorganic acid alkali metal salt (D )
• the haze was reduced to 105% or less ( Specifically, the polishing rate was higher than 105% while being maintained in the range of 98 to 105%.
• the polishing composition containing D can achieve both a polishing rate and high surface quality.

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