JP2022045161A - Polishing composition, wetting agent for semiconductor, water-soluble polymer, and manufacturing method of them - Google Patents

Abstract

To provide a polishing composition containing a water-soluble polymer, capable of achieving an excellent surface state on a substrate.SOLUTION: There is provided a polishing composition containing a water-soluble polymer. In the polishing composition, the water-soluble polymer is a water-soluble polymer processed by a method including steps of: preparing a solution by dissolving a raw-material water-soluble polymer into a solvent; and applying a pressure onto the solution by allowing collision in the solution.SELECTED DRAWING: None

Description

The present invention relates to a polishing composition, a wetting agent for semiconductors, a water-soluble polymer, and a method for producing these.

Water-soluble polymers are used in various applications such as dispersants, thickeners, emulsion polymerization stabilizers, protective colloids, paints, cosmetics, water retention agents, pharmaceutical preparations, and polishing aids. Among these, hydroxyethyl cellulose, which is a semi-synthetic polymer compound, is particularly excellent in properties such as dispersibility and viscosity increase. Hydroxyethyl cellulose is used in addition to abrasive grains and water as a polishing aid to improve the protection and wettability of the substrate surface, especially in the rinsing process and polishing process of various substrates such as semiconductor substrates represented by silicon wafers. Has been done.

Patent Document 1 discloses a method for producing dry hydrophobic hydroxyethyl cellulose, which is useful as a polishing aid that can improve the polishing rate in combination with abrasive grains. Specifically, Patent Document 1 discloses that the synthesized undried hydrophobic hydroxyethyl cellulose is dried and then pulverized to obtain dry hydrophobic hydroxyethyl cellulose.

Japanese Unexamined Patent Publication No. 2019-104781

However, with the development of technology, higher quality is desired for the surface condition required for a polishing object such as a semiconductor substrate, a semiconductor element or a silicon wafer.

Therefore, it is an object of the present invention to provide a polishing composition, a wetting agent for semiconductors, a water-soluble polymer, and a method for producing these, which can achieve a good surface condition of a substrate.

The above problems of the present invention can be solved by the following means:
A polishing composition containing abrasive grains and a water-soluble polymer.
The water-soluble polymer is
The process of dissolving a water-soluble polymer as a raw material in a solvent to make a solution,
A polishing composition which is a water-soluble polymer treated by a method comprising a step of colliding the solutions with each other and applying pressure to the solutions.

A method for producing a polishing composition containing abrasive grains and a water-soluble polymer.
The process of dissolving a water-soluble polymer as a raw material in a solvent to make a solution,
The step of colliding the solutions with each other and applying pressure to the solutions,
The process of mixing the abrasive grains with the pressured solution, and
A method for producing a composition for polishing, including.

The above-mentioned problems of the present invention can also be solved by the following means:
A wetting agent for semiconductors containing a water-soluble polymer,
The water-soluble polymer is
The process of dissolving a water-soluble polymer as a raw material in a solvent to make a solution,
The step of colliding the solutions with each other and applying pressure to the solutions,
A wetting agent for semiconductors, which is a water-soluble polymer treated by a method comprising.

A method for manufacturing a wetting agent for semiconductors containing a water-soluble polymer.
The process of dissolving a water-soluble polymer as a raw material in a solvent to make a solution,
The step of colliding the solutions with each other and applying pressure to the solutions,
A method for manufacturing a wetting agent for semiconductors, including.

Furthermore, the above problems of the present invention can also be solved by the following means:
The process of dissolving a water-soluble polymer as a raw material in a solvent to make a solution,
The step of colliding the solutions with each other and applying pressure to the solutions,
A water-soluble polymer for polishing compositions and / or semiconductor wetting agents, treated by a method comprising:

The process of dissolving a water-soluble polymer as a raw material in a solvent to make a solution,
The step of colliding the solutions with each other and applying pressure to the solutions,
A method for producing a water-soluble polymer for polishing compositions and / or semiconductor wetting agents.

According to the present invention, there are provided a polishing composition, a wetting agent for semiconductors, and a water-soluble polymer capable of achieving a good surface condition of a substrate. More specifically, polishing and / or rinsing with the polishing composition and / or semiconductor wetting agent according to the present invention can further reduce the number of defects observed on the substrate. In particular, it is effective in reducing defects such as LPD-N (Light Point Defect Non-cleable) and LPD (Light Point Defect).

Further, according to the present invention, it is possible to selectively remove the high molecular weight body of the water-soluble polymer used in the production of the polishing composition and / or the wetting agent for semiconductors. Then, by selectively removing the high molecular weight molecule, the filterability of the solution containing the water-soluble polymer, the polishing composition and / or the wetting agent for semiconductors can be improved. Further, it is possible to selectively remove the high molecular weight molecule without increasing the amount of impurities contained in the water-soluble polymer and the solution containing the water-soluble polymer.

FIG. 1 is a GPC elution curve of the raw material water-soluble polymer and the water-soluble polymer to be treated when HEC1 is used as the raw material water-soluble polymer in the examples. FIG. 2 is a GPC elution curve of the raw material water-soluble polymer and the water-soluble polymer to be treated when HEC2 is used as the raw material water-soluble polymer in the examples. FIG. 3 is a differential molecular weight distribution curve of the raw material water-soluble polymer and the treated water-soluble polymer when HEC1 is used as the raw material water-soluble polymer in the examples. FIG. 4 is a differential molecular weight distribution curve of the raw material water-soluble polymer and the treated water-soluble polymer when HEC2 is used as the raw material water-soluble polymer in the examples.

Hereinafter, embodiments of the present invention will be described. The present invention is not limited to the following embodiments. Further, in the present specification, "XY" indicating a range means "X or more and Y or less". Unless otherwise specified, the operation and physical properties are measured under the conditions of room temperature (range of 20 ° C. or higher and 25 ° C. or lower) / relative humidity of 40% RH or higher and 50% RH or lower.

The mechanism by which the above problems can be solved by the present invention has not been completely clarified, but the present inventors speculate about some of them as follows.

In the present invention, by applying pressure to the solution containing the raw material water-soluble polymer, the entanglement of the high molecular weight body of the raw material water-soluble polymer is eliminated, and the molecular chain of the high molecular weight body of the raw material water-soluble polymer is broken. As a result, the high molecular weight molecule of the raw material water-soluble polymer is removed, the viscosity is lower than that of the raw material water-soluble polymer before the treatment, and the obtained water-soluble polymer (in the present specification, simply "highly water-soluble to be treated". Improves the filterability of solutions containing (also referred to as "molecules"), polishing compositions and / or wetting agents for semiconductors.

In addition, as a method of applying pressure to the solution containing the raw material water-soluble polymer, the solutions containing the raw material water-soluble polymer are made to collide with each other and the pressure is applied to the solution, and the collision with other members is not adopted. Therefore, it is difficult for impurities to be mixed.

As a result, high molecular weight molecules that cause surface defects can be removed from the raw material water-soluble polymer, and the increase in impurities due to the treatment of the raw material water-soluble polymer can be prevented. Thereby, when polishing and / or rinsing with the polishing composition and / or the semiconductor wetting agent according to the present invention, the number of surface defects (for example, LPD-N or LPD) of the substrate is further reduced. It is thought that it can be done.

Here, the mechanism in which the high molecular weight substance is selectively removed has not been completely clarified, but the present inventors speculate about a part thereof as follows.

That is, in the collision step, the high molecular weight body in the raw material water-soluble polymer has a higher collision frequency than the low molecular weight body, and the high molecular weight body breaks the molecular chain more than the low molecular weight body. Since a large number of points are contained as a ratio, it is considered that the high molecular weight molecule is selectively removed.

The above mechanism is based on speculation, and its correctness does not affect the technical scope of the present invention.

Hereinafter, the details of the present invention will be described, but the present invention is not limited to the following description.

<Polishing composition, wetting agent for semiconductors, and manufacturing method thereof>
One embodiment of the present invention is a composition for polishing containing abrasive grains and a water-soluble polymer, wherein the water-soluble polymer is a step of dissolving a raw material water-soluble polymer in a solvent to prepare a solution (the present invention). Processing by a method comprising a step (also simply referred to as a "dissolution step" in the specification) and a step of colliding the solutions with each other to apply pressure to the solution (also simply referred to as a "collision step" in the present specification). The present invention relates to a composition for polishing, which is a water-soluble polymer obtained.

Another embodiment of the present invention is a wetting agent for a semiconductor containing a water-soluble polymer, wherein the water-soluble polymer is a water-soluble polymer treated by a method including a dissolution step and a collision step. There is a wetting agent for semiconductors.

Hereinafter, the treatment applied to the water-soluble polymer used in the polishing composition and / or the wetting agent for semiconductors of the present application will be described.

<< Treatment of water-soluble polymers and treated water-soluble polymers >>
One embodiment of the present invention is a method for treating a water-soluble polymer used in a polishing composition and / or a wetting agent for semiconductors, in which a raw material water-soluble polymer is dissolved in a solvent to prepare a solution (dissolution step). ), And a step of colliding the solutions with each other to apply pressure to the solution (collision step), and the present invention relates to a method for treating a water-soluble polymer (that is, a water-soluble polymer to be treated). Another aspect of the present invention relates to a water-soluble polymer for polishing compositions and / or semiconductor wetting agents, which has been treated by a method comprising a melting step and a collision step.

[Dissolution step]
The water-soluble polymer of the present invention is a water-soluble polymer treated by a method including a step of dissolving a raw material water-soluble polymer in a solvent to prepare a solution (dissolution step).

As used herein, "dissolving" means dissolving or dispersing. And, "dissolving" is preferably in a state where at least a part is dissolved, and at this time, the other remaining part may be in a state of being dispersed in a solvent, but in a state of being completely dissolved. Is particularly preferred.

(Raw material water-soluble polymer)
The type of the raw material water-soluble polymer of the present invention is not particularly limited as long as it is a water-soluble polymer compound. For example, examples of the polymer compound include those containing a hydroxyl group, a carboxyl group, an acyloxy group, a sulfo group, an amide structure, an imide structure, a quaternary ammonium structure, a heterocyclic structure, a vinyl structure, an ether bond and the like in the molecule.

In the present specification, "water-soluble" means that the solubility in water (25 ° C.) is 1 g / 100 mL or more, and "polymer compound" has a weight average molecular weight (Mw) of 2,. A compound that is 000 or more. The weight average molecular weight (Mw) can be measured by gel permeation chromatography (GPC), and the details of the measuring method are described in Examples.

As the raw material water-soluble polymer, any of a natural polymer compound, a semi-synthetic polymer compound, and a synthetic polymer compound may be used. The natural polymer compound is not particularly limited, but preferred examples thereof include polysaccharides and the like. The semi-synthetic polymer compound is not particularly limited, but preferably includes a cellulose derivative, a starch derivative and the like. The synthetic polymer compound is not particularly limited, but preferably includes a polymer having an oxyalkylene unit, a polymer having a structural unit derived from vinyl alcohol, a polymer having a nitrogen atom, and the like. In one embodiment of the present invention, the raw material water-soluble polymer contains a hydroxyl group or an ether group from the viewpoint of improving the surface quality. Among them, it is preferable to contain at least one of a polymer having a structural unit derived from vinyl alcohol and a cellulose derivative. Polishing compositions and / or semiconductor wetting agents containing these polymers tend to improve surface quality after polishing and / or rinsing steps. Specific examples of these compounds are given below.

The polysaccharide is not particularly limited, and examples thereof include carrageenan and xanthan gum.

The cellulose derivative is not particularly limited, and for example, hydroxyethyl cellulose (hereinafter, also simply referred to as “HEC”), hydroxypropyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, ethyl cellulose, ethyl hydroxyethyl cellulose, carboxymethyl cellulose and the like. Examples include cellulose derivatives and purulans. As the type of the cellulose derivative, one type may be used alone, or two or more types may be used in combination. Here, the cellulose derivative means a derivative in which a part of the hydroxyl group of cellulose is substituted with another substituent.

The starch derivative is not particularly limited, and examples thereof include cationic starch, phosphate starch, and carboxymethyl starch salt.

The polymer having an oxyalkylene unit is not particularly limited, but is a block copolymer of polyethylene oxide (PEO), polypropylene oxide (PPO), ethylene oxide (EO) and propylene oxide (PO) or butylene oxide (BO). Examples thereof include coalescence, random copolymers of EO and PO or BO, and the like. Among them, a block copolymer of EO and PO or a random copolymer of EO and PO is preferable. The block copolymer of EO and PO can be a diblock body containing a PEO block and a polypropylene oxide (PPO) block, a triblock body, or the like. Examples of the above-mentioned triblock body include PEO-PPO-PEO type triblock body and PPO-PEO-PPO type triblock body. Of these, the PEO-PPO-PEO type triblock body is more preferable.

In a block copolymer or random copolymer of EO and PO, the molar ratio [EO / PO] of EO and PO constituting the copolymer is determined from the viewpoint of solubility in water, cleanability, and the like. It is preferably larger than 1, more preferably 2 or more, and even more preferably 3 or more. In a more preferred embodiment, the molar ratio [EO / PO] is, for example, 5 or more.

The polymer having a structural unit derived from vinyl alcohol may contain only a vinyl alcohol unit (hereinafter, also referred to as “VA unit”) as a repeating unit, and may contain only a repeating unit other than the VA unit in addition to the VA unit (hereinafter, also referred to as “VA unit”). Hereinafter, it may also include "non-VA unit"). As the type of polymer having a structural unit derived from vinyl alcohol, one type may be used alone, or two or more types may be used in combination. The vinyl alcohol unit is a structural portion represented by the following chemical formula: -CH ₂ -CH (OH)-;. The polymer having a structural unit derived from vinyl alcohol may be a random copolymer containing VA units and non-VA units, or may be a block copolymer or a graft copolymer. The polymer having a structural unit derived from vinyl alcohol may contain only one kind of non-VA unit, or may contain two or more kinds of non-VA units.

The polymer having a structural unit derived from vinyl alcohol used in the raw material water-soluble polymer disclosed herein may be unmodified polyvinyl alcohol (non-modified PVA) or modified polyvinyl alcohol (modified PVA). ) May be. Here, the non-modified PVA is produced by hydrolyzing (saponifying) polyvinyl acetate, and is other than the repeating unit (-CH ₂ -CH (OCOCH ₃ )-) and the VA unit having a vinyl acetate-polymerized structure. A polymer having structural units derived from vinyl alcohol that does not substantially contain repeating units. The saponification degree of the non-modified PVA may be, for example, 60% or more, 70% or more, 80% or more, or 90% or more from the viewpoint of water solubility. In some embodiments, non-modified PVA having a saponification degree of 95% or more, or non-modified PVA having a saponification degree of 98% or more can be preferably adopted as the raw material water-soluble polymer.

Examples of the non-VA unit that can be contained in the modified PVA include a repeating unit derived from an N-vinyl type monomer and an N- (meth) acryloyl type monomer described later, a repeating unit derived from ethylene, and a repeating unit derived from an alkyl vinyl ether. Examples thereof include, but are not limited to, a repeating unit derived from a vinyl ester of a monocarboxylic acid having 3 or more carbon atoms. A preferable example of the above-mentioned N-vinyl type monomer is N-vinylpyrrolidone. A preferable example of the N- (meth) acryloyl type monomer is N- (meth) acryloyl morpholine. The alkyl vinyl ether may be a vinyl ether having an alkyl group having 1 or more and 10 or less carbon atoms, such as propyl vinyl ether, butyl vinyl ether, and 2-ethylhexyl vinyl ether. 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, for example, vinyl propanoate, vinyl butanoate, vinyl pentanate, vinyl hexanoate and the like. obtain.

Polymers with structural units derived from vinyl alcohol include VA units, oxyalkylene groups, carboxy groups, sulfo groups, amino groups, hydroxyl groups, amide groups, imide groups, nitrile groups, ether groups, ester groups, and these. It may be a modified PVA containing a non-VA unit having at least one structure selected from the salt.

The polymer having a structural unit derived from vinyl alcohol may be a modified PVA in which a part of the VA unit contained in the polymer having a structural unit derived from vinyl alcohol is acetalized with an aldehyde compound or a ketone compound. .. In a preferred embodiment of the technique disclosed herein, the acetalized modified PVA is a polymer obtained by the acetalization reaction of the above-mentioned non-modified PVA with an aldehyde compound.

In one embodiment of the invention, the aldehyde compound used to produce acetalized modified PVA is not particularly limited. In a preferred embodiment, the aldehyde compound has 1 to 7 carbon atoms, more preferably 2 to 7 carbon atoms.

Examples of the aldehyde compound include formaldehyde; linear or branched alkyl aldehydes such as acetaldehyde, propion aldehyde, n-butyl aldehyde, iso butyl aldehyde, t-butyl aldehyde and hexyl aldehyde; and alicyclic type such as cyclohexane carvaldehide and benzaldehyde. 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. Of these, straight-chain or branched alkylaldehydes are preferable because they are highly soluble in water and easy to acetalize, and among them, acetaldehyde, n-propylaldehyde, n-butyraldehyde, and n-pentylaldehyde are preferable. Is more preferable.

As the aldehyde compound, in addition to the above, an aldehyde compound having 8 or more carbon atoms such as 2-ethylhexyl aldehyde, nonanal aldehyde, and decyl aldehyde may be used.

Further, as the polymer having a structural unit derived from vinyl alcohol, a cationically modified polyvinyl alcohol having a cationic group such as a quaternary ammonium structure introduced may be used. As the cationically modified polyvinyl alcohol, for example, a cationic group derived from a monomer having a cationic group such as a diallyldialkylammonium salt or an N- (meth) acryloylaminoalkyl-N, N, N-trialkylammonium salt is introduced. The ones that have been done are listed.

The ratio of the number of moles of VA units to the number of moles of all repeating units constituting the polymer having structural units derived from vinyl alcohol may be, for example, 5% or more, 10% or more, or 20% or more. However, it may be 30% or more. Although not particularly limited, in some embodiments, the proportion of the number of moles of the VA unit may be 50% or more, 65% or more, 75% or more, or 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 polymer having a structural unit derived from vinyl alcohol may be VA units. Here, "substantially 100%" means that a polymer having a structural unit derived from vinyl alcohol does not contain non-VA units at least intentionally, and is typically the number of moles of all repeating units. This includes cases where the proportion of the number of moles of non-VA units occupying is less than 2% (for example, less than 1%) and is 0%. In some other embodiments, the ratio of the number of moles of VA units to the number of moles of all repeating units constituting the polymer having structural units derived from vinyl alcohol may be, for example, 95% or less, 90%. It may be less than or equal to, 80% or less, and 70% or less.

The content of VA units (content on a mass basis) in a polymer having a structural unit derived from vinyl alcohol may be, for example, 5% by mass or more, 10% by mass or more, or 20% by mass or more. It may be 30% by mass or more. Although not particularly limited, in some embodiments, the content of the VA unit may be 50% by mass or more (for example, more than 50% by mass), 70% by mass or more, or 80% by mass or more (for example, more than 50% by mass). For example, 90% by mass or more, 95% by mass or more, or 98% by mass or more) may be used. Substantially 100% by mass of the repeating units constituting the polymer having a structural unit derived from vinyl alcohol may be VA units. Here, "substantially 100% by mass" means that a non-VA unit is not contained as a repeating unit constituting a polymer having a structural unit derived from vinyl alcohol, at least intentionally, and typically vinyl. It means that the content of non-VA units in a polymer having a structural unit derived from alcohol is less than 2% by mass (for example, less than 1% by mass). In some other embodiments, the content of VA units in the polymer having structural units derived from vinyl alcohol may be, for example, 95% by mass or less, 90% by mass or less, or 80% by mass or less. , 70% by mass or less may be used.

The polymer having a structural unit derived from vinyl alcohol may contain a plurality of polymer chains having different contents of VA units in the same molecule. Here, the polymer chain refers to a portion (segment) constituting a part of a single molecule polymer. For example, a polymer having a structural unit derived from vinyl alcohol has a polymer chain A having a VA unit content of more than 50% by mass and a VA unit content of less than 50% by mass (that is, a non-VA unit content). The polymer chain B (which has an amount of more than 50% by mass) may be contained 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 mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more. In some embodiments, the content of VA units in the polymer chain A may be 95% by weight or more, or 98% by weight or more. Substantially 100% by mass of the repeating units constituting the polymer chain A may be VA units.

The polymer chain B may contain only non-VA units as repeating units, and may contain VA units in addition to non-VA units. The content of the non-VA unit in the polymer chain B may be 60% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more. In some embodiments, the content of non-VA units in the polymer chain B 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 B may be non-VA units.

Examples of polymers having a structural unit derived from vinyl alcohol containing the polymer chain A and the polymer chain B in the same molecule include block copolymers and graft copolymers containing these polymer chains. The graft copolymer may be a graft copolymer having a structure in which the polymer chain B (side chain) is grafted to the polymer chain A (main chain), or the polymer chain A (side chain) may be attached to the polymer chain B (main chain). It may be a graft copolymer having a structure in which the chain) is grafted. In one embodiment, a polymer having a structural unit derived from vinyl alcohol having a structure in which the polymer chain B is grafted to the polymer chain A can be used.

Examples of the polymer chain B include a polymer chain having a repeating unit derived from an N-vinyl type monomer as a main repeating unit, and a polymer chain having a repeating unit derived from an N- (meth) acryloyl type monomer as a main repeating unit. , Polymer chains and the like having an oxyalkylene unit as a main repeating unit. In the present specification, the main repeating unit means a repeating unit contained in excess of 50% by mass, unless otherwise specified.

As a preferred example of the polymer chain B, a polymer chain having an N-vinyl type monomer as a main repeating unit, that is, an N-vinyl-based polymer chain can be mentioned. The content of the repeating unit derived from the N-vinyl type monomer in the N-vinyl polymer chain is typically more than 50% by mass, may be 70% by mass or more, and may be 85% by mass or more. It may be 95% by mass or more. Substantially all of the polymer chain B may be a repeating unit derived from an N-vinyl type monomer.

In this specification, examples of N-vinyl type monomers include monomers having a nitrogen-containing heterocycle (for example, a lactam ring) and N-vinyl chain amides. Specific examples of the N-vinyllactam type monomer include N-vinylpyrrolidone, N-vinylpiperidone, N-vinylmorpholinone, N-vinylcaprolactam, N-vinyl-1,3-oxadin-2-one, and N-vinyl-. Examples thereof include 3,5-morpholindione. Specific examples of the N-vinyl chain amide include N-vinylacetamide, N-vinylpropionic acid amide, N-vinylbutyric acid amide and the like. The polymer chain B is, for example, an N-vinyl-based polymer chain in which more than 50% by mass (for example, 70% by mass or more, 85% by mass or more, or 95% by mass or more) of the repeating unit is an N-vinylpyrrolidone unit. possible. Substantially all of the repeating units constituting the polymer chain B may be N-vinylpyrrolidone units.

As another example of the polymer chain B, a polymer chain having a repeating unit derived from an N- (meth) acryloyl type monomer as a main repeating unit, that is, an N- (meth) acryloyl-based polymer chain can be mentioned. The content of the repeating unit derived from the N- (meth) acryloyl type monomer in the N- (meth) acryloyl polymer chain is typically more than 50% by mass, may be 70% by mass or more, and may be 85% by mass. It may be 5% by mass or more, or 95% by mass or more. Substantially all of the polymer chain B may be a repeating unit derived from an N- (meth) acryloyl type monomer.

As used herein, examples of N- (meth) acryloyl-type monomers include chain amides having an N- (meth) acryloyl group and cyclic amides having an N- (meth) acryloyl group. Examples of chain amides having an N- (meth) acryloyl group are (meth) acrylamide; N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, N-isopropyl ( N-alkyl (meth) acrylamide such as meta) acrylamide, Nn-butyl (meth) acrylamide; N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dipropyl (meth) ) N, N-dialkyl (meth) acrylamide such as acrylamide, N, N-diisopropyl (meth) acrylamide, N, N-di (n-butyl) (meth) acrylamide; and the like. Examples of cyclic amides having an N- (meth) acryloyl group include N- (meth) acryloylmorpholine, N- (meth) acryloylpyrrolidine and the like.

Another example of the polymer chain B is a polymer chain containing an oxyalkylene unit as a main repeating unit, that is, an oxyalkylene-based polymer chain. The content of the oxyalkylene unit in the oxyalkylene polymer chain is typically more than 50% by mass, may be 70% by mass or more, may be 85% by mass or more, and may be 95% by mass or more. There may be. Substantially all of the repeating units contained in the polymer chain B may be oxyalkylene units.

Examples of the oxyalkylene unit include an oxyethylene unit, an oxypropylene unit, an oxybutylene unit and the like. Each such oxyalkylene unit can be a repeating unit derived from the corresponding alkylene oxide. The oxyalkylene unit contained in the oxyalkylene polymer chain may be one kind or two or more kinds. For example, it may be an oxyalkylene polymer chain containing an oxyethylene unit and an oxypropylene unit or a butylene oxide unit in combination. In an oxyalkylene polymer chain containing two or more types of oxyalkylene units, the oxyalkylene units may be random copolymers of the corresponding alkylene oxides, block copolymers or graft copolymers. May be good. Among them, a block copolymer of oxyethylene unit and oxypropylene unit or a random copolymer of oxyethylene unit and oxypropylene unit is preferable. The block copolymer of an oxyethylene unit and an oxypropylene unit may be a diblock copolymer containing a polyethylene oxide (PEO) block and a polypropylene oxide (PPO) block, a triblock copolymer or the like. Examples of the above-mentioned triblock copolymers include PEO-PPO-PEO type triblock copolymers and PPO-PEO-PPO type triblock copolymers. Usually, PEO-PPO-PEO type triblock copolymer is more preferable.

As yet another example of the polymer chain B, a polymer chain containing a repeating unit derived from an alkyl vinyl ether (for example, a vinyl ether having an alkyl group having 1 or more and 10 or less carbon atoms), a monocarboxylic acid vinyl ester (for example, the number of carbon atoms). A polymer chain containing a repeating unit derived from (vinyl ester of 3 or more monocarboxylic acids), a part of VA units was acetalized with an aldehyde (for example, an alkyl aldehyde having an alkyl group having 1 or more and 7 or less carbon atoms). Examples thereof include a polymer chain, a polymer chain into which a cationic group (for example, a cationic group having a quaternary ammonium structure) has been introduced, and the like.

As the polymer having a structural unit derived from vinyl alcohol in the raw material water-soluble polymer disclosed herein, non-modified PVA may be used, modified PVA may be used, and the non-modified PVA and the modified PVA may be used. It may be used in combination. In the embodiment in which the non-modified PVA and the modified PVA are used in combination, the amount of the modified PVA used is, for example, less than 95% by mass with respect to the total amount of the polymer having a structural unit derived from vinyl alcohol contained in the raw material water-soluble polymer. It may be 90% by mass or less, 75% by mass or less, 50% by mass or less, 30% by mass or less, 10% by mass or less, 5% by mass or less, or 1% by mass or less. .. The raw material water-soluble polymer disclosed herein can be preferably carried out, for example, in an embodiment in which only one or more types of non-modified PVA are used as the polymer having a structural unit derived from vinyl alcohol.

The polymer having a nitrogen atom is not particularly limited, and includes a polymer containing an N-vinyl type monomer unit, an imine derivative, a polymer containing an N- (meth) acryloyl type monomer unit; and the like. For example, poly N-acryloyl morpholine (PACMO), poly N-vinylpyrrolidone (PVP), polyhydroxylethylacrylamide (PHEAA), poly N-vinylimidazole (PVI), poly N-vinylcarbazole, poly N-vinylcaprolactam, poly. Examples thereof include N-vinylpiperidin. Among them, it is preferable to contain poly N-acryloyl morpholine (PACMO) from the viewpoint of reducing the haze of the substrate. As the type of polymer having a nitrogen atom, one type may be used alone, or two or more types may be used in combination.

Among these, a semi-synthetic polymer compound or a synthetic polymer compound is preferable, and a semi-synthetic polymer compound is more preferable, from the viewpoint that the effect of improving the filterability of the present invention becomes more remarkable. In one embodiment of the present invention, the raw material water-soluble polymer preferably contains a hydroxyl group or an ether group from the viewpoint of improving surface quality, more preferably a cellulose derivative, for example, and hydroxyethyl cellulose (HEC). It is more preferable to have.

The weight average molecular weight (Mw) of the raw material water-soluble polymer is not particularly limited as long as it is 2,000 or more as described above. From the viewpoint that the effect of improving the filterability of the present invention becomes more remarkable, it is preferably 10,000 or more, and more preferably 100,000 or more. Further, the weight average molecular weight (Mw) of the raw material water-soluble polymer is preferably 4,000,000 or less, more preferably 3,000,000 or less, and 2,800 from the viewpoint of filterability. It is more preferably 000 or less, and particularly preferably 1,500,000 or less. Further, the dispersity of the raw material water-soluble polymer (also referred to as “Mw / Mn” in the present specification: where Mw represents a weight average molecular weight and Mn represents a number average molecular weight) is not particularly limited, but its value. The greater the value, the greater the effect of the present invention tends to be. From this viewpoint, the lower limit of Mw / Mn of the raw material water-soluble polymer is, for example, preferably 5 or more, more preferably 10 or more, further preferably 15 or more, and 20 or more. Is even more preferable. The upper limit of Mw / Mn of the raw material water-soluble polymer is preferably 95 or less, more preferably 90 or more, further preferably 85 or more, and even more preferably 80 or more. The upper limit of Mw / Mn of the raw material water-soluble polymer can be, for example, 75 or less and 40 or less. The weight average molecular weight (Mw) and the number average molecular weight (Mn) can be measured by gel permeation chromatography (GPC), and the details of the measuring method will be described in Examples.

According to one embodiment of the present invention, the raw material water-soluble polymer is a polymer having a structural unit derived from vinyl alcohol. The weight average molecular weight (Mw) of the polymer having a structural unit derived from vinyl alcohol is preferably 2,000 or more, more preferably 2,500 or more, and further preferably 5,000 or more. It is preferable, and even more preferably 10,000 or more. According to such an embodiment, there is a technical effect that the surface quality after the polishing and / or rinsing process is improved. According to one embodiment of the present invention, the weight average molecular weight (Mw) of the polymer having a structural unit derived from polyvinyl alcohol is preferably 500,000 or less, more preferably 300,000 or less. It is more preferably 200,000 or less, and even more preferably 150,000 or less. According to such an embodiment, the filterability is improved.

According to one embodiment of the present invention, the raw material water-soluble polymer is a cellulose derivative. The weight average molecular weight (Mw) of the cellulose derivative is preferably 2,000 or more, more preferably 10,000 or more, further preferably 100,000 or more, for example, 150,000 or more. It may be present, and may be 200,000 or more. Further, in some embodiments, it is preferably 350,000 or more, more preferably 500,000 or more, even more preferably 700,000 or more, and preferably 900,000 or more. It is particularly preferable, for example, it may be 1,250,000 or more. According to such an embodiment, there is a technical effect that the surface quality after the polishing and / or rinsing process is improved. According to one embodiment of the present invention, the weight average molecular weight (Mw) of the cellulose derivative is preferably 4,000,000 or less, more preferably 3,000,000 or less, and 2,800. It is more preferably 000 or less, further preferably 1,500,000 or less, particularly preferably 1,000,000 or less, and may be, for example, 750,000 or less, 450. It may be 000 or less. According to such an embodiment, the filterability is improved.

According to one embodiment of the present invention, the raw material water-soluble polymer is a polymer having a nitrogen atom. The weight average molecular weight (Mw) of the polymer having a nitrogen atom is preferably 2,000 or more, more preferably 4,000 or more, still more preferably 10,000 or more, and 20,000. The above is even more preferable. According to such an embodiment, there is a technical effect that the surface quality after the polishing and / or rinsing process is improved. According to one embodiment of the present invention, the weight average molecular weight (Mw) of the raw material water-soluble polymer having a nitrogen atom is preferably 1,600,000 or less, preferably 1,250,000 or less. Is more preferable, 750,000 or less is further preferable, and 400,000 or less is even more preferable. According to such an embodiment, the filterability is improved.

The weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution of the water-soluble polymer can be measured by gel permeation chromatography (GPC). adopt.

According to one embodiment of the present invention, the content of the raw material water-soluble polymer in the dissolution step is preferably 0.5% by mass or more, preferably 1% by mass or more, from the viewpoint of crushing efficiency in the crushing step. It is more preferable to have it, and it is further preferable to have it in an amount of 1.5% by mass or more. In one embodiment of the present invention, the content of the raw material water-soluble polymer in the dissolution step is preferably 5% by mass or less, more preferably 4% by mass or less, and 3% by mass or less from the viewpoint of solubility. Is more preferable.

As the raw material water-soluble polymer according to one embodiment of the present invention, it is preferable to use powder.

As the raw material water-soluble polymer, one type may be used alone, or two or more types may be used in combination, but it is preferable to use one type alone.

(solvent)
As used herein, the term "solvent" refers to a solvent or a dispersion medium. The solvent is not particularly limited as long as it can dissolve the raw material water-soluble polymer, but it preferably contains water. The content of water in the solvent is not particularly limited, but is preferably 50% by mass or more, more preferably 90% by mass or more, and 100% by mass (water only) with respect to the total mass of the solvent. It is more preferable to have. As the water, water containing as little impurities as possible is preferable from the viewpoint of preventing contamination of the substrate and inhibition of the action of other components. For example, water having a total content of transition metal ions of 100 ppb or less is preferable. Here, the purity of water can be increased by, for example, operations such as removal of impurity ions using an ion exchange resin, removal of foreign substances by a filter, distillation and the like. Specifically, as the water, for example, deionized water (ion-exchanged water), pure water, ultrapure water, distilled water and the like are preferably used.

Further, the solvent may be an organic solvent or a mixed solvent of water and an organic solvent as long as the solubility of the raw material water-soluble polymer can be improved. The organic solvent is not particularly limited, and a known organic solvent can be used. When the mixed solvent of water and an organic solvent is used, acetone, acetonitrile, ethanol, methanol, isopropanol, glycerin, ethylene glycol, propylene glycol and the like, which are organic solvents to be mixed with water, are preferably used. When an organic solvent is used, water and an organic solvent may be mixed, and each component may be added and dissolved in the obtained mixed solvent, or these organic solvents may be used without being mixed with water as a raw material. After dissolving the water-soluble polymer, it may be mixed with water. These organic solvents can be used alone or in combination of two or more.

The dissolution method in the dissolution step is not particularly limited as long as it can dissolve the raw material water-soluble polymer in the solvent, but a method of adding the raw material water-soluble polymer to the solvent and stirring is preferable. The stirring method is not particularly limited, and a known method can be appropriately used. The stirring temperature is not particularly limited, but is generally preferably 10 to 40 ° C. Further, the stirring time is not particularly limited.

[Collision process]
The water-soluble polymer of the present invention is a water-soluble polymer treated by a method including a step (collision step) of colliding the solutions obtained through the above dissolution step with each other and applying pressure to the solution. In the collision step, as a result of two or more solutions colliding with each other, pressure is applied to these solutions. The device for applying pressure to the solution is not particularly limited, and a known device can be used. A preferred example is a jet mill.

A jet mill is a device that atomizes particles of a substance to be treated by collision with each other or between particles and a flow path wall in a liquid phase flow. More specifically, a high-speed flow is generated by an arbitrary method to cause a collision between the liquids to be treated or the liquid to be treated and the flow path wall, and the turbulence / shearing and cavitation effects caused by the high-speed flow are effectively effective. It is a general term for devices that have the function of atomizing raw materials in the liquid to be treated and promoting dispersion. Typical methods include a method in which the liquid to be treated is ejected from a nozzle by a plunger pump, a rotary pump, etc. and collides with a fixed plate at high speed, and a method in which the injected liquids collide with each other from the front. .. When the liquid to be treated passes through the nozzle in the flow path at high speed or passes while colliding, it receives turbulence and shearing, and when it is released under reduced pressure immediately after the collision, a cavitation effect occurs and it is released rapidly. Due to the impact of pressure, the raw material in the liquid to be treated is significantly atomized. In the present invention, a method is used in which the jetted liquids to be treated collide with each other from the front. This makes it possible to prevent impurities from being mixed.

Jet mills are particularly excellent in the selective removal effect of high molecular weight molecules of raw material water-soluble polymers. Here, the selective removal effect of the high molecular weight substance is (1) that the amount of the high molecular weight substance is reduced, (2) the amount of the low molecular weight substance is maintained, and (3) the differential molecular weight that will be described later. It means that the peak top molecular weight (peak top molecular weight: Mp) in the distribution curve is maintained. As a result, the filterability of the solution containing the water-soluble polymer to be treated, the polishing composition and / or the wetting agent for semiconductors is further enhanced, and the polishing and / or the wetting agent for semiconductors is used for polishing and / or rinsing. The number of defects (LPD-N, LPD, etc.) on the substrate can be further reduced.

The jet mill is not particularly limited, and for example, a known technique described in JP-A-2015-18853 can be used. Further, for example, a commercially available device such as Starburst Lab (manufactured by Sugino Machine Limited) can be used.

The processing conditions of the jet mill are not particularly limited because they change depending on the equipment used, and are appropriately adjusted according to the object of the collision process and the effect of selectively removing the high molecular weight substance after the target collision process. can do.

For example, the processing pressure is not particularly limited, but is preferably 5 MPa or more, more preferably 10 MPa or more, further preferably 15 MPa or more, still more preferably 20 MPa or more, for example, 30 MPa or more, 40 MPa or more, 50 MPa or more, 100 MPa or more. It may be 200 MPa or more. Within this range, the effect of selectively removing high molecular weight substances is higher. In addition, the filterability of the solution containing the water-soluble polymer to be treated, the polishing composition, and / or the wetting agent for semiconductors is further enhanced. The processing pressure is not particularly limited, but is preferably 900 MPa or less, more preferably 500 MPa or less, and even more preferably 250 MPa or less. Within this range, the amount of low molecular weight is maintained and the change in peak top molecular weight (Mp) is small.

The treatment time is not particularly limited, but is preferably 1 minute or longer, more preferably 10 minutes or longer, even more preferably 20 minutes or longer, still more preferably 30 minutes or longer, for example, 40 minutes or longer, 80 minutes or longer. It may be 100 minutes or more. Within this range, the effect of selectively removing high molecular weight substances is higher. In addition, the filterability of the solution containing the water-soluble polymer to be treated, the polishing composition, and / or the wetting agent for semiconductors is further enhanced. The processing time is not particularly limited, but is preferably 600 minutes or less, more preferably 500 minutes or less, further preferably 400 minutes or less, for example, 300 minutes or less, 200 minutes or less. , 150 minutes or less. Within this range, the amount of low molecular weight is maintained and the change in peak top molecular weight (Mp) is small.

Further, the flow rate of the treatment liquid is not particularly limited, but is preferably 10 mL / min or more, more preferably 50 mL / min or more, and further preferably 80 mL / min or more. Within this range, the effect of selectively removing high molecular weight substances is higher. In addition, the filterability of the solution containing the water-soluble polymer to be treated, the polishing composition, and / or the wetting agent for semiconductors is further enhanced. The flow rate of the treatment liquid is preferably 100,000 mL / min or less, more preferably 10,000 mL / min or less, further preferably 1000 mL / min or less, and further preferably 800 mL / min or less. It is preferably 600 mL / min or less, and particularly preferably 600 mL / min or less. Within this range, the amount of low molecular weight is maintained and the change in peak top molecular weight (Mp) is small.

The number of treatments is not particularly limited, but may be, for example, once or more, preferably three or more, and more preferably five or more. Within this range, the effect of selectively removing high molecular weight substances is higher. In addition, the filterability of the solution containing the water-soluble polymer to be treated, the polishing composition, and / or the wetting agent for semiconductors is further enhanced. The number of treatments is preferably 20 or less, more preferably 10 or less, and even more preferably 8 or less. Within this range, the amount of low molecular weight is maintained and the change in peak top molecular weight (Mp) is small.

(Water-soluble polymer to be treated)
As described above, the water-soluble polymer to be treated is preferably one in which the high molecular weight molecule of the raw material water-soluble polymer is selectively removed by the collision step. Further, it is preferable that the amount of the low molecular weight body is maintained and the change in the peak top molecular weight (Mp) is small.

In the present specification, the high molecular weight body represents a component having a higher molecular weight than the peak top molecular weight (Mp). More specifically, in the differential molecular weight distribution curve of the water-soluble polymer, it represents a component corresponding to LogM on the higher molecular weight side than LogM at which dw / d (LogM) peaks.

Further, in the present specification, the low molecular weight body represents a component having a lower molecular weight than the peak top molecular weight (Mp). More specifically, it represents a component corresponding to LogM on the lower molecular weight side than LogM at which dw / d (LogM) peaks in the differential molecular weight distribution curve of the water-soluble polymer.

The water-soluble polymer to be treated in the present invention is not particularly limited, but at least the following [1] to [3] from the viewpoint that the high molecular weight molecule of the raw water-soluble polymer is selectively removed. ] It is preferable that it has any of the characteristics. Further, the water-soluble polymer preferably has two or more of the following properties [1] to [3], and more preferably all of the properties.

[1] Decrease in the amount of high molecular weight molecule The change in the amount of high molecular weight molecule of the water-soluble polymer to be treated can be confirmed as follows. That is, (1) draw the differential molecular weight distribution curves of the raw material water-soluble polymer and the treated water-soluble polymer, respectively. (2) When the value of the vertical axis dw / d (LogM) is 20, the larger of the two values of the horizontal axis LogM, LogM (R) and LogM (P), are extracted, respectively. (3) LogM (P) of the water-soluble polymer to be treated is compared with LogM (R) of the raw water-soluble polymer. Here, when LogM (P) is smaller than LogM (R), it can be said that the high molecular weight substance has decreased.

Since the larger the reduction amount of the high molecular weight substance is, the more preferable it is. Therefore, the smaller the ratio of LogM (P) / LogM (R) (ratio of LogM (P) to LogM (R)) (%) is preferable. The ratio is, for example, preferably 98% or less, more preferably 85% or less, further preferably 80% or less, further preferably 65% or less, and even more preferably 60% or less. It is particularly preferable that it is present, and it is even more preferable that it is 45% or less. When the ratio is within the above range, the polishing composition and / or the wetting agent for semiconductors according to the present invention are densely adsorbed on the wafer, so that surface defects can be further reduced. The ratio can be lowered by increasing the pressure applied to the solution in the collision step. In jet mill processing, for example, by increasing the processing pressure, the ratio can be reduced.

[2] Maintaining the amount of low molecular weight substance The change in the amount of low molecular weight substance of the water-soluble polymer to be treated can be confirmed as follows. That is, (1) draw the differential molecular weight distribution curves of the raw material water-soluble polymer and the treated water-soluble polymer, respectively. (2) The vertical axis dw / d (LogM) of the raw material water-soluble polymer and the water-soluble polymer to be treated when the value of the horizontal axis LogM is 4.5 is extracted, respectively. (3) The dw / d (LogM (p)) of the water-soluble polymer to be treated is compared with the dw / d (LogM (r)) of the raw water-soluble polymer. Here, when the difference between dw / d (LogM (p)) and dw / d (LogM (r)) is small, it can be said that the amount of the low molecular weight substance is maintained.

Since the change in the amount of the low molecular weight substance is preferable as it is smaller, dw with respect to the ratio of [dw / d (LogM (p))] / [dw / d (LogM (r))] (dw / d (LogM (r))). / D (ratio of LogM (p))) (%) is preferably closer to 100%. The range may be, for example, 100 ± 5%, preferably 100 ± 3%, more preferably 100 ± 2%, still more preferably 100 ± 1%, and 100 ±. 0.8% is even more preferable, 100 ± 0.5% is particularly preferable, 100 ± 0.3% is even more preferable, and 100 ± 0.1% is extremely preferable. When the ratio is within the above range, it is considered that the function of densely protecting the wafer, which is exhibited by the low molecular weight body of the raw material water-soluble polymer, can be maintained. Therefore, it is possible to further reduce surface defects when polishing with the polishing composition containing the water-soluble polymer to be treated and / or the wetting agent for semiconductors according to the present invention.

[3] Maintenance of peak top molecular weight (Mp) Changes in the peak top molecular weight (Mp) of the water-soluble polymer to be treated can be confirmed as follows. That is, (1) draw the differential molecular weight distribution curves of the raw material water-soluble polymer and the treated water-soluble polymer, respectively. (2) LogM having a peak in dw / d (LogM) is extracted. (3) LogM (p_peak) of the water-soluble polymer to be treated is compared with LogM (r_peak) of the raw water-soluble polymer. Here, when the difference between LogM (p_peak) and LogM (r_peak) is small, it can be said that the change in peak top molecular weight (Mp) is small.

Since it is preferable that the change in the peak top molecular weight (Mp) is small, the ratio of LogM (p_peak) / LogM (r_peak) (ratio of LogM (p_peak) to LogM (r_peak)) (%) is preferably close to 100%. The range is, for example, preferably 100 ± 5%, more preferably 100 ± 4%, further preferably 100 ± 3%, even more preferably 100 ± 2%, 100 ± 1 5.5% is particularly preferable, 100 ± 1% is even more preferable, 100 ± 0.5% is extremely preferable, and 100 ± 0.1 is even more preferable. When the ratio is within the above range, it is considered that the function of more uniformly protecting the wafer can be maintained. Therefore, it is possible to further reduce surface defects when polishing with the polishing composition containing the water-soluble polymer to be treated and / or the wetting agent for semiconductors according to the present invention.

The differential molecular weight distribution curve of the polymer can be created by using a general method, and the details of the creating method will be described in Examples. For the calculation of the area in the GPC dissolution curve and the differential molecular weight distribution curve obtained by the measurement by the GPC method, use the analysis software installed in the GPC device (manufactured by Tosoh Corporation, trade name "HLC-8420 GPC"). Can be done using.

The water-soluble polymer to be treated has the following characteristics in addition to the above-mentioned specifications [1] to [3].

The Mw / Mn of the water-soluble polymer to be treated is not particularly limited, but is preferably 30 or less, more preferably 25 or less, further preferably 20 or less, and further preferably 15 or less. It is more preferably 10 or less, still more preferably 8 or less, and may be, for example, 7.5 or less (typically 7 or less). Within this range, the number of defects (for example, LPD-N and LPD) in the polishing composition containing the water-soluble polymer to be treated and / or the substrate polished by the semiconductor wetting agent can be further reduced. can. Further, the solution containing the water-soluble polymer to be treated, the composition for polishing and / or the wetting agent for semiconductors have more excellent filterability. Further, the Mw / Mn of the water-soluble polymer to be treated is preferably 1 or more.

It is preferable that the ratio (%) of the dispersity (Mw / Mn) of the water-soluble polymer to be treated to the dispersity (Mw / Mn) of the raw material water-soluble polymer is low. The above ratio is not particularly limited, but is preferably 90% or less, more preferably 80% or less, further preferably 75% or less, still more preferably 70% or less, and 30%. % Or less is particularly preferable, 25% or less is particularly preferable, and 20% or less is extremely preferable. The smaller the ratio, the narrower the molecular weight distribution, and it means that the water-soluble polymer to be treated having a more uniform weight molecular weight is obtained. Further, the ratio is preferably 1% or more, more preferably 5% or more, further preferably 10% or more, and particularly preferably 15% or more. When the ratio is in the above range, the amount of the low molecular weight substance tends to be maintained. Further, when the ratio is within the above range, the particle size of the raw material water-soluble polymer becomes more uniform, and the wafer can be protected more closely. Therefore, it is possible to further reduce surface defects when polishing and / or rinsing with the polishing composition containing the water-soluble polymer to be treated and / or the wetting agent for semiconductors. The ratio can be lowered by increasing the pressure applied to the solution in the collision step. In jet mill processing, for example, by increasing the processing pressure, the ratio can be reduced.

The water-soluble polymer to be treated obtained through the collision step has an advantage that the difference between the amount of impurities in the water-soluble polymer to be treated and the amount of impurities in the raw material water-soluble polymer is small. In particular, the difference in the amount of metal impurities becomes small. It is considered that this is because in the collision step, the solutions collide with each other and pressure is applied to the solutions, and collision with other members is not adopted, so that impurities are unlikely to be mixed. The amount of metal impurities can be evaluated by measuring the concentration of metal impurities by inductively coupled plasma (ICP) emission spectrometry. As a measuring device, for example, an inductively coupled high frequency plasma spectroscopic analyzer manufactured by Shimadzu Corporation. "ICP-AES" can be used. Depending on the type of metal impurity, it may be carried out using an inductively coupled plasma mass spectrometer (ICP-MS) or an atomic absorption spectrometer.

<< Manufacturing method of polishing composition and wetting agent for semiconductors >>
One embodiment of the present invention is a method for producing a polishing composition containing abrasive grains and a water-soluble polymer (water-soluble polymer to be treated), in which a raw material water-soluble polymer is dissolved in a solvent to prepare a solution. A polishing composition comprising a step (dissolution step), a step of colliding the solutions with each other to apply pressure to the solution (collision step), and a step of mixing abrasive grains with the pressured solution. Regarding the manufacturing method of.

Another embodiment of the present invention is a method for producing a wetting agent for semiconductors containing a water-soluble polymer (water-soluble polymer to be treated), which comprises a dissolution step, a collision step, and the above-mentioned solution to which pressure is applied. The present invention relates to a method for producing a wetting agent for semiconductors, which comprises a step of mixing the components of the above.

In these forms, the water-soluble polymer to be treated is described in the above-mentioned treatment of the water-soluble polymer and the description of the water-soluble polymer to be treated. Further, the dissolution step and the collision step are described in the above-mentioned treatment of the water-soluble polymer and the water-soluble polymer to be treated.

Further, the method for producing a polishing composition and / or a wetting agent for a semiconductor according to an embodiment of the present invention may include a plurality of mixing steps, in which case another step is added between the mixing steps. It may be included. For example, a filtration step described later may be provided after the mixing step for a certain component, and then a mixing step for other components described later may be provided.

[Mixing process]
The polishing composition of the present invention is produced by a method including a step (mixing step) of mixing at least other components including abrasive grains with the solution obtained through the above collision step. Here, the other components are components other than the water-soluble polymer to be treated obtained from the raw material water-soluble polymer through the above-mentioned dissolution step and the collision step, and the solvent used in the above-mentioned dissolution step and the collision step. Is. Other components include, for example, basic compounds, organic acids or salts thereof, inorganic acids or salts thereof, surfactants, chelating agents, preservatives, antifungal agents, and water-soluble polymers other than water-soluble polymers to be treated. , Dispersants and the like, and examples thereof include various components used in known polishing compositions. These other components can be mixed to the extent that the effects of the present invention are not significantly impaired. As an example of at least other components containing abrasive grains, for example, only abrasive grains can be mentioned.

Further, the wetting agent for semiconductors of the present invention is produced by a method including a step (mixing step) of mixing the other components without mixing the abrasive grains with the solution obtained through the collision step.

The mixing method, mixing conditions, etc. of various components in the mixing step are not particularly limited. For example, various components may be added to the solution obtained through the collision step, or the solution obtained through the collision step may be added to various components. Further, the order of addition of various components is not particularly limited, and these may be added simultaneously, sequentially, or only some components may be added at the same time. The mixing temperature is not particularly limited, but is generally preferably 10 to 40 ° C., and may be heated in order to increase the dissolution rate. Further, the mixing time is not particularly limited. The mixing device is also not particularly limited. For example, a well-known mixing device such as a blade type stirrer, an ultrasonic disperser, or a homomixer can be used.

Hereinafter, various components added in the mixing step will be described.

(Abrasion grain)
The material and properties of the abrasive grains are not particularly limited, and can be appropriately selected depending on the purpose and mode of use of the polishing composition. Examples of abrasive grains include inorganic particles, organic particles, and organic-inorganic composite particles. Specific examples of the inorganic particles include silica particles, alumina particles, cerium oxide particles, chromium oxide particles, titanium dioxide particles, zirconium oxide particles, magnesium oxide particles, manganese dioxide particles, zinc oxide particles, and oxide particles such as red iron oxide particles; Nitride particles such as silicon nitride particles and boron nitride particles; carbide particles such as silicon carbide particles and boron carbide particles; diamond particles; carbonates such as calcium carbonate and barium carbonate can be mentioned. Specific examples of the organic particles include polymethylmethacrylate (PMMA) particles, poly (meth) acrylic acid particles, polyacrylonitrile particles and the like. Here, (meth) acrylic acid has the meaning of comprehensively referring to acrylic acid and methacrylic acid. Such abrasive grains may be used alone or in combination of two or more. The semiconductor wetting agent does not contain abrasive grains.

As the abrasive grains, inorganic particles are preferable, particles made of a metal or metalloid oxide are preferable, and silica particles are particularly preferable. In a polishing composition that can be used for polishing a substrate having a surface made of silicon, for example, finish polishing, such as a silicon wafer described later, it is particularly meaningful to use silica particles as abrasive grains. The technique disclosed herein can be preferably carried out, for example, in an embodiment in which the abrasive grains are substantially composed of silica particles. Here, "substantially" means that 95% by mass or more of the particles constituting the abrasive grains are silica particles. 98% by mass or more, preferably 99% by mass or more, for example, 100% by mass of the particles constituting the abrasive grains may be silica particles.

Specific examples of the silica particles include colloidal silica, fumed silica, and precipitated silica. The silica particles may be used alone or in combination of two or more. The use of colloidal silica is particularly preferable because it is easy to obtain a polished surface having excellent surface quality after polishing. As the colloidal silica, for example, colloidal silica produced from water glass (Na silicate) by an ion exchange method or alkoxide method colloidal silica can be preferably adopted. Here, the alkoxide method colloidal silica refers to colloidal silica produced by a hydrolysis condensation reaction of alkoxysilane. Colloidal silica can be used alone or in combination of two or more.

The true specific gravity of the abrasive grain constituent material is preferably 1.5 or more, more preferably 1.6 or more. The abrasive grain constituent material is, for example, silica constituting silica particles. As the true specific gravity of the abrasive grain constituent material increases, the physical polishing ability tends to increase. As the physical polishing ability of the abrasive grains increases, the local stress exerted by the abrasive grains on the surface of the substrate generally tends to increase. From this point of view, abrasive grains having a true specific density of 1.7 or more are particularly preferable. The upper limit of the true specific gravity of the abrasive grains is not particularly limited, but is typically 2.3 or less, for example, 2.2 or less. As the true specific gravity of the abrasive grains (for example, silica particles), a measured value by a liquid replacement method using ethanol as a replacement liquid can be adopted.

The average primary particle diameter (BET diameter) of the abrasive grains is not particularly limited, but is preferably 5 nm or more, more preferably 10 nm or more, and further preferably 15 nm or more from the viewpoint of polishing efficiency and the like. .. From the viewpoint of obtaining a higher polishing effect, for example, haze reduction, defect removal, and the like, the BET diameter is preferably 15 nm or more, and more preferably 20 nm or more, for example, more than 20 nm. The average primary particle diameter of the abrasive grains is preferably 100 nm or less, more preferably 80 nm or less, and further preferably 60 nm or less, from the viewpoint of suppressing the local stress applied to the substrate surface by the abrasive grains. preferable. The technique disclosed herein has an average primary particle diameter of 50 nm or less, typically less than 40 nm, more preferably 35 nm or less, still more preferably 32 nm or less, because it is easy to obtain a higher quality surface. Can also be preferably carried out in the embodiment of.

The value of the average primary particle diameter of the abrasive grains is calculated from, for example, the specific surface area measured by the BET method. The specific surface area of the abrasive grains can be measured, for example, by using "Flow SorbII 2300" manufactured by Micromeritex. In the present specification, the BET diameter means the BET diameter (nm) = 6000 / (true density (g / cm ³ ) × BET value (m ² / g)) from the specific surface area (BET value) measured by the BET method. The particle size calculated by the formula of.

The average secondary particle diameter of the abrasive grains is not particularly limited, but is preferably 10 nm or more, more preferably 15 nm or more, further preferably 20 nm or more, still more preferably 25 nm, from the viewpoint of polishing efficiency and the like. The above is particularly preferable. The average secondary particle diameter is preferably 30 nm or more, and more preferably 40 nm or more, from the viewpoint of obtaining a higher polishing effect, for example, an effect of reducing haze, removing defects, and the like. The average secondary particle diameter of the abrasive grains is preferably 300 nm or less, more preferably 200 nm or less, and more preferably 150 nm or less, from the viewpoint of suppressing local stress applied to the surface of the substrate by the abrasive grains. It is even more preferably 125 nm or less, and even more preferably 125 nm or less. The technique disclosed herein also uses an abrasive grain having an average secondary particle diameter of 100 nm or less, for example, less than 80 nm (typically 45 nm or less), because a higher quality surface can be easily obtained. Preferably, the reduction in the average secondary particle size of the abrasive grains that can be performed improves the stability of the polishing composition. The average secondary particle diameter of the abrasive grains can be measured, for example, by a dynamic light scattering method using the model "UPA-UT151" manufactured by Nikkiso Co., Ltd.

The shape (outer shape) of the abrasive grains may be spherical or non-spherical. Specific examples of the non-spherical particles include a peanut shape, that is, a peanut shell shape, a cocoon shape, a konpeito shape, a rugby ball shape, and the like. For example, peanut-shaped abrasive grains, many of which are peanut-shaped, can be preferably adopted.

Although not particularly limited, the average value of the major axis / minor axis ratio of the abrasive grains, that is, the average aspect ratio is, in principle, 1.0 or more, preferably 1.05 or more, and more preferably 1.1 or more. Is. Higher polishing efficiency can be achieved by increasing the average aspect ratio. The average aspect ratio of the abrasive grains is preferably 3.0 or less, more preferably 2.0 or less, still more preferably 1.5 or less, from the viewpoint of scratch reduction and the like.

The shape (outer shape) and average aspect ratio of the abrasive grains can be grasped by, for example, observation with an electron microscope. As a specific procedure for grasping the average aspect ratio, for example, using a scanning electron microscope (SEM), for a predetermined number of silica particles capable of recognizing the shape of independent particles, the minimum circumscribing to each particle image. Draw a rectangle. The predetermined number is, for example, 200. Then, for the rectangle drawn for each particle image, the value obtained by dividing the length of the long side (value of the major axis) by the length of the short side (value of the minor axis) is the major axis / minor axis ratio (aspect ratio). ). The average aspect ratio can be obtained by arithmetically averaging the aspect ratios of the predetermined number of particles.

(Water-soluble polymer)
The polishing composition and / or the wetting agent for semiconductors of the present invention contains the above-mentioned water-soluble polymer to be treated. Raw Material of Water-Soluble Polymer to Be Treated The water-soluble polymer may contain two or more kinds of water-soluble polymers. Preferably, the raw material water-soluble polymer of the water-soluble polymer to be treated is one kind of water-soluble polymer.

The content of the water-soluble polymer to be treated in the polishing composition and / or the wetting agent for semiconductors is not particularly limited, but from the viewpoint of surface quality after the polishing and / or rinsing process, the content is based on 100 parts by mass of the solvent. It is preferably 0.0001 parts by mass or more, more preferably 0.0005 parts by mass or more, further preferably 0.001 parts by mass or more, and further preferably 0.0015 parts by mass or more. It is particularly preferably 0.002 parts by mass or more, and may be, for example, 0.05 parts by mass or more (typically 0.1 parts by mass or more). Further, the content of the water-soluble polymer to be treated in the polishing composition and / or the wetting agent for semiconductors is preferably 5 parts by mass or less with respect to 100 parts by mass of the solvent from the viewpoint of filterability. It is more preferably 3 parts by mass or less, further preferably 2 parts by mass or less, further preferably 1 part by mass or less, and particularly preferably 0.5 part by mass or less, for example. It may be 0.3 parts by mass or less (typically 0.2 parts by mass or less).

The polishing composition and / or the wetting agent for a semiconductor according to one embodiment of the present invention is a water-soluble polymer other than the above-mentioned water-soluble polymer to be treated (hereinafter, "" Also referred to as "arbitrary polymer"). Examples of the optional polymer include water-soluble polymers of the type exemplified in the above dissolution step. Examples of water-soluble polymers other than those exemplified include polyisoprene sulfonic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, polyisoamylene sulfonic acid, polystyrene sulfonic acid salt, polyacrylic acid salt, polyvinyl acetate and the like. Can be mentioned. Any polymer may be used alone or in combination of two or more.

The content of the arbitrary polymer in the polishing composition and / or the wetting agent for semiconductors is not particularly limited, but may be the content of the water-soluble polymer to be treated described in the above mixing step. The ratio of the content of the water-soluble polymer to be treated and the content of the optional polymer is not particularly limited, but from the viewpoint of surface quality after the polishing step, the ratio of the optional polymer to the total content of the water-soluble polymer is 70%. It is preferably less than or equal to, more preferably 60% or less, further preferably 50% or less, further preferably 40% or less, further preferably 30% or less, and even more preferably 20%. The following is particularly preferable, and for example, it may be 10% or less, or 5% or less.

In one embodiment of the present invention, when the polishing composition and / or the semiconductor wetting agent is in the state of a concentrated liquid, the content of the water-soluble polymer in the polishing composition and / or the semiconductor wetting agent is determined. From the viewpoint of improving stability, it is preferably 0.0001% by mass or more, more preferably 0.0005% by mass or more, further preferably 0.001% by mass or more, and 0.01% by mass. The above is particularly preferable. In one embodiment of the present invention, when the polishing composition and / or the semiconductor wetting agent is in the state of a concentrated liquid, the content of the water-soluble polymer in the polishing composition and / or the semiconductor wetting agent is determined. From the viewpoint of storage stability, filterability and the like, it is preferably 5% by mass or less, more preferably 3% by mass or less, and further preferably 1% by mass or less.

In one embodiment of the invention, when the polishing composition and / or the wetting agent for semiconductors is in a diluted state, the content of the water-soluble polymer improves the surface quality after the polishing and / or rinsing process. From this viewpoint, it is preferably 0.00005% by mass or more, more preferably 0.0001% by mass or more, further preferably 0.0005% by mass or more, and particularly preferably 0.001% by mass or more. preferable. Further, in one embodiment of the present invention, when the polishing composition and / or the wetting agent for semiconductors is in a diluted state, the content of the water-soluble polymer is 0.1 mass by mass from the viewpoint of maintaining the polishing rate. % Or less is preferable, 0.05% by mass or less is more preferable, and 0.01% by mass or less is further preferable. In the above, the content of the water-soluble polymer refers to the total amount of the polishing composition and / or the semiconductor wetting agent when the water-soluble polymer is contained in two or more kinds.

(Dispersant)
The dispersion medium contained in the polishing composition and / or the wetting agent for semiconductors is not particularly limited, but is preferably of the type exemplified in the above-mentioned dissolution step, for example. In particular, it is preferable to use the solvent used in the dissolution step and / or the collision step as it is. The solvent used in the dissolution step and / or the collision step usually functions as a dispersion medium in the polishing composition and / or the wetting agent for semiconductors, especially with respect to the abrasive grains.

(Basic compound)
As used herein, the basic compound refers to a compound having a function of dissolving in water and raising the pH of an aqueous solution. As the basic compound, an organic or inorganic basic compound containing nitrogen, an alkali metal hydroxide, an alkaline earth metal hydroxide, various carbonates, hydrogen carbonate and the like can be used. Examples of the basic compound containing nitrogen include a quaternary ammonium compound, a quaternary phosphonium compound, ammonia, an amine and the like. The amine is preferably a water-soluble amine. Such basic compounds may be used alone or in combination of two or more.

Specific examples of alkali metal hydroxides include potassium hydroxide and sodium hydroxide. Specific examples of the carbonate or hydrogen carbonate 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- (β-aminoethyl) ethanolamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, and anhydrous piperazine. , Piperazine hexahydrate, 1- (2-aminoethyl) piperazine, N-methylpiperazine, guanidine, azoles such as imidazole and triazole, and the like. Specific examples of the quaternary phosphonium compound include quaternary phosphonium hydroxides such as tetramethylphosphonium hydroxide and tetraethylphosphonium hydroxide.

As the quaternary ammonium compound, a quaternary ammonium salt such as a tetraalkylammonium salt or a hydroxyalkyltrialkylammonium salt can be preferably used. Quaternary ammonium salts are typically strong bases. The anionic component in such a quaternary ammonium salt can be, for example, OH ⁻ , F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , ClO _4- ^, BH _4- ^and the like. Among them, a preferable example is a quaternary ammonium salt having an anion of OH ⁻ , that is, a quaternary ammonium hydroxide. Specific examples of the quaternary ammonium hydroxide include hydroxylation of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrapentylammonium hydroxide and tetrahexylammonium hydroxide. Tetraalkylammonium; hydroxyalkyltrialkylammonium hydroxide such as 2-hydroxyethyltrimethylammonium (also referred to as choline); and the like.

Among these basic compounds, for example, at least one basic compound selected from alkali metal hydroxides, quaternary ammonium hydroxide and ammonia can be preferably used. Of these, tetraalkylammonium hydroxide and ammonia are more preferable, and ammonia is particularly preferable. Examples of the tetraalkylammonium hydroxide include tetramethylammonium hydroxide.

When the polishing composition and / or the semiconductor wetting agent disclosed herein contains a basic compound, the content of the basic compound in the polishing composition and / or the semiconductor wetting agent is not particularly limited. From the viewpoint of suitably treating the surface of the substrate, the content of the concentrated solution or the diluted solution is usually preferably 0.0001% by mass or more, and 0.0005% by mass or more, for example, 0. It is more preferably 001% by mass or more, typically 0.002% by mass or more. Further, from the viewpoint of improving the surface quality and the like, the content is preferably less than 15% by mass, preferably less than 10% by mass, more preferably less than 5% by mass, and 1. It is more preferably less than 0% by mass, and even more preferably less than 0.5% by mass.

(Organic acid or its salt, inorganic acid or its salt)
Examples of organic acids include fatty acids such as formic acid, acetic acid and propionic acid, aromatic carboxylic acids such as benzoic acid and phthalic acid, citric acid, oxalic acid, tartrate acid, malic acid, maleic acid, fumaric acid, succinic acid and organic. Examples thereof include sulfonic acid and organic phosphonic acid. Examples of the organic acid salt include alkali metal salts of organic acids such as sodium salt, potassium salt and the like, ammonium salt and the like. Examples of inorganic acids include sulfuric acid, nitric acid, hydrochloric acid, carbonic acid and the like. Examples of the inorganic acid salt include alkali metal salts of inorganic acids such as sodium salt, potassium salt and the like, and ammonium salts. The organic acid and its salt, and the inorganic acid and its salt may be used alone or in combination of two or more.

(Oxidant)
Examples of the oxidizing agent include hydrogen peroxide (H ₂ O ₂ ), sodium persulfate, ammonium persulfate, sodium dichloroisocyanurate and the like. The polishing composition and the wetting agent for semiconductors disclosed herein preferably contain substantially no oxidizing agent. When the polishing composition and / or the semiconductor wetting agent contains an oxidizing agent, the polishing composition and / or the semiconductor wetting agent is supplied to the polishing object, so that the surface of the polishing object is surfaced. Is oxidized to form an oxide film. This is because the surface quality of the substrate may be deteriorated, and the action of the polishing composition and / or the wetting agent for semiconductors on the substrate surface may be deteriorated. The substrate is, for example, a silicon wafer. In addition, the fact that the polishing composition and / or the wetting agent for semiconductors do not substantially contain an oxidizing agent means that the oxidizing agent is not contained at least intentionally.

(Surfactant)
As the surfactant, any of anionic, cationic, nonionic and amphoteric ones can be used. Generally, anionic or nonionic surfactants may be preferably employed. Nonionic surfactants are more preferable from the viewpoint of low foaming property and ease of pH adjustment. Examples of nonionic surfactants are oxyalkylene polymers such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol; polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl amines and polyoxyethylene fatty acids. Polyoxyalkylene derivatives such as esters, polyoxyethylene glyceryl ether fatty acid esters, polyoxyethylene sorbitan fatty acid esters (eg, polyoxyalkylene adducts); copolymers of multiple oxyalkylenes (eg, diblock type copolymers). , Triblock type copolymer, random type copolymer, alternate copolymer); and the like. In one embodiment, a surfactant containing a polyoxyalkylene structure (for example, polyoxyethylene structure, polyoxypropylene structure, etc.) in one molecule can be preferably adopted. The surfactant may be used alone or in combination of two or more.

(Chelating agent)
Examples of chelating agents include aminocarboxylic acid-based chelating agents and organic phosphonic acid-based chelating agents. Examples of aminocarboxylic acid-based chelating agents include ethylenediamine tetraacetic acid, sodium ethylenediamine tetraacetate, nitrilotriacetic acid, sodium nitrilotriacetate, ammonium nitrilotriacetic acid, hydroxyethylethylenediamine triacetic acid, sodium hydroxyethylethylenediamine triacetate, and diethylenetriaminepentaacetic acid. , Diethylenetriamine pentaacetate sodium, triethylenetetramine hexaacetic acid and triethylenetetramine hexaacetate sodium. Examples of organic phosphonic acid-based chelating agents include 2-aminoethylphosphonic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, aminotri (methylenephosphonic acid), ethylenediaminetetrakis (methylenephosphonic acid), and diethylenetriaminepenta (methylenephosphonic acid). Acid), Etan-1,1-diphosphonic acid, Etan-1,1,2-triphosphonic acid, Etan-1-hydroxy-1,1-diphosphonic acid, Etan-1-hydroxy-1,1,2-triphosphonic acid , Etan-1,2-dicarboxy-1,2-diphosphonic acid, methanehydroxyphosphonic acid, 2-phosphonobutane-1,2-dicarboxylic acid, 1-phosphonobutane-2,3,4-tricarboxylic acid and α-methylphospho Contains nosuccinic acid. Of these, organic phosphonic acid-based chelating agents are more preferable. Of these, ethylenediaminetetrakis (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid) and diethylenetriaminepentaacetic acid are preferable. Particularly preferred chelating agents include ethylenediamine tetrakis (methylenephosphonic acid) and diethylenetriaminepenta (methylenephosphonic acid). The chelating agent may be used alone or in combination of two or more.

[Filtration process]
The polishing composition and / or semiconductor wetting agent according to one embodiment of the present invention is a step of filtering a solution used for producing the polishing composition and / or the semiconductor wetting agent (the present specification). Then, it may be manufactured by a method including simply (also referred to as “filtration step”).

In the method for producing a polishing composition and / or a semiconductor wetting agent according to a preferred embodiment of the present invention, the solution obtained through the collision step is filtered after the collision step and before the mixing step. It is a method that further includes a step. Further, the method for producing a polishing composition and / or a semiconductor wetting agent according to a preferred embodiment of the present invention further includes a step of filtering the solution obtained through the mixing step after the above mixing step. Is. The production method according to the embodiment of the present invention may further include a step of filtering the solution at both of the above timings.

The material of the filter used in the filtration step is not particularly limited, and is, for example, cellulose mixed ester, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer, polycarbonate, poly. Ethersulfone, cellulose acetate, nitrocellulose, regenerated cellulose, polyamide, triacetyl cellulose, polypropylene, polyvinylidene chloride (PVC), nylon, nylon 66, polysulfone, polyester, polypropylene / polyethylene, acrylic copolymer, polycarbonate, polylactic acid, Examples thereof include resins such as polycaprolactone, polyglycolic acid, polydioxanone, polyhydroxybutyrate, polybutadiene, polyurethane, polystyrene (PS), polymethyl methacrylate, and polycarbonate, glass, and metals.

The structure of the filter is also not particularly limited, and examples thereof include a depth structure, a pleated structure, and a membrane structure.

The pore size of the filter is not particularly limited, but is preferably 0.03 μm or more, more preferably 0.04 μm or more, further preferably 0.05 μm or more, and further preferably 0.1 μm or more. Even more preferably, it is particularly preferably 0.2 μm or more. When the pore diameter of the filter is 0.03 μm or more, for example, 0.04 μm or more, a high filtration rate can be obtained, which is preferable. The pore size of the filter is preferably 100 μm or less, more preferably 70 μm or less, further preferably 50 μm or less, further preferably 15 μm or less, and particularly preferably 1 μm or less. It is preferable (specifically, it is preferably 0.5 μm or less). When the pore diameter of the filter is 100 μm or less, the accuracy of filtration is further improved.

The filtration method may be any of natural filtration, suction filtration, pressure filtration and centrifugal filtration performed at normal pressure.

[Other processes]
Even if the polishing composition and / or the semiconductor wetting agent according to the embodiment of the present invention is further produced through steps other than the dissolution step, the collision step, the mixing step, and the filtration step. good.

≪Polishing composition, wetting agent for semiconductors≫
The polishing composition and / or semiconductor wetting agent of the present invention has the following properties.

(D90)
The D90 (P) of the particles in the polishing composition of the present invention is smaller than the D90 (R) of the particles in the polishing composition containing the raw material water-soluble polymer which has not been treated with the present invention. Here, D90 is a particle diameter in which the integrated mass from the small particle diameter side of the integrated particle diameter distribution on a volume basis is 90%. The ratio (%) of D90 (P) to D90 (R) is not particularly limited, but is preferably 99.5% or less, more preferably 95% or less, and further preferably 90% or less. When the ratio is in this range, the number of defects (for example, LPD-N or LPD) in the substrate polished and / or rinsed by the polishing composition and / or the semiconductor wetting agent can be further reduced. In addition, the dispersibility of the abrasive grains in the polishing composition is improved, and the polishing property has better filterability. The ratio is preferably 50% or more, more preferably 60% or more, still more preferably 70% or more. When the ratio is in this range, it is possible to prevent the particle size from becoming too small and the physical processing force (for example, polishing rate) from decreasing. The polishing composition D90 can be obtained by a dynamic light scattering method using UPA-UT151 manufactured by Nikkiso Co., Ltd., and the details of the measurement method will be described in Examples.

(PH)
The pH of the polishing composition according to one embodiment of the present invention is preferably 8.0 or higher, more preferably 8.5 or higher, further preferably 9.0 or higher, and 9. It is even more preferably 5 or more, and particularly preferably 10.0 or more. As the pH of the polishing composition increases, the polishing efficiency tends to improve. On the other hand, from the viewpoint of preventing the dissolution of the abrasive grains and suppressing the deterioration of the mechanical polishing action, the pH of the polishing composition is preferably 13.0 or less, more preferably 12.5 or less. It is more preferably 12.0 or less, further preferably 11.5 or less, particularly preferably 11.0 or less, further particularly preferably 10.8 or less, for example, 10 It may be 5.5 or less, or 10.0 or less.

The pH of the wetting agent for semiconductors according to one embodiment of the present invention is preferably 8.0 or higher, more preferably 8.5 or higher, further preferably 9.0 or higher, and 9. It is even more preferably 5 or more, and particularly preferably 10.0 or more. The pH of the wetting agent for semiconductors is preferably 13.0 or less, more preferably 12.5 or less, further preferably 12.0 or less, and preferably 11.5 or less. Even more preferably, it is particularly preferably 11.0 or less, further particularly preferably 10.8 or less, and for example, it may be 10.5 or less, or 10.0 or less. When the pH of the semiconductor wetting agent is within the above range, the surface of the substrate can be suitably treated.

The pH is measured by using a pH meter, calibrating at three points using a standard buffer solution, placing the glass electrode in the composition to be measured, and measuring the value after stabilizing after 2 minutes or more. Can be grasped. As the pH meter, for example, LAQUA (registered trademark) manufactured by HORIBA, Ltd. or an equivalent product thereof can be used. The standard buffers are 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.) can be used.

<Polishing and rinsing method>
One embodiment of the present invention is a method of polishing a substrate using a polishing composition containing abrasive grains and a water-soluble polymer to be treated. Another aspect of the present invention is a method of rinsing a substrate using a wetting agent for semiconductors containing a water-soluble polymer to be treated.

In these forms, the abrasive grains are the same as those described in the above description of the method for producing the polishing composition and the wetting agent for semiconductors. Further, the water-soluble polymer to be treated is the same as that described in the above-mentioned treatment of the water-soluble polymer and the description of the water-soluble polymer to be treated.

Hereinafter, a preferred embodiment of a method of polishing and / or rinsing a substrate using the polishing composition and / or the semiconductor wetting agent according to the present invention will be described.

First, a polishing liquid and / or a rinsing liquid containing the polishing composition and / or the semiconductor wetting agent according to the present invention is prepared. Preparing the polishing liquid and / or the rinsing liquid includes preparing the polishing liquid and the rinsing liquid by subjecting the polishing composition and / or the wetting agent for semiconductors to operations such as concentration adjustment and pH adjustment. .. Examples of the concentration adjustment include dilution. Alternatively, the polishing composition and / or the semiconductor wetting agent may be used as it is as the polishing liquid and / or the rinsing liquid.

Then, the polishing liquid and / or the rinsing liquid is supplied to the substrate, and polishing and / or rinsing is performed by a conventional method. For example, when performing finish polishing and / or rinsing of a silicon wafer, typically, the silicon wafer that has undergone the wrapping process is set in a general polishing device, and the surface to be polished of the silicon wafer is passed through the polishing pad of the polishing device. Is supplied with a polishing solution and / or a rinsing solution. Typically, while continuously supplying the polishing liquid and / or the rinsing liquid, the polishing pad is pressed against the surface to be polished of the silicon wafer to relatively move them, for example, rotate them. The polishing and / or rinsing of the substrate is completed through such a polishing step.

The polishing composition and / or the wetting agent for semiconductors according to one embodiment of the present invention can be preferably applied to a polishing step or a rinsing step of a substrate such as a silicon wafer. The substrate is applied to the substrate in a process upstream of the polishing step and the rinsing step, such as wrapping and etching, before the polishing step and / or the rinsing step with the polishing composition and / or the semiconductor wetting agent according to the present invention. It may be subjected to general processing that can be performed.

The polishing compositions and / or semiconductor wetting agents disclosed herein are used, for example, in policing and rinsing substrates (eg, silicon wafers) prepared to a surface condition with a surface roughness of 0.01 nm to 100 nm by an upstream process. It can be preferably used. The surface roughness Ra of the substrate is, for example, SchmittMeasurementSystem Inc. It can be measured using a laser scan type surface roughness meter "TMS-3000WRC" manufactured by the same company. The polishing composition and / or the wetting agent for semiconductors disclosed herein are effective for use in final polishing (finish polishing), polishing immediately before the final polishing (finish polishing), or rinsing, and are particularly preferable for use in final polishing. Here, the final policing refers to the final policing step in the manufacturing process of the target product, that is, a step in which no further policing is performed after the step. The polishing composition disclosed herein may be used in a polishing step upstream of final polishing. Here, the polishing step upstream of the final polishing refers to the pre-polishing step between the rough polishing step and the final polishing step. Typically, it includes at least a primary policing step, and may further include a policing step such as a secondary, tertiary ... The semiconductor wetting agent disclosed herein may be used in a rinsing step performed after a polishing step upstream of final policing.

(Concentrate)
The polishing composition and / or semiconductor wetting agent disclosed herein may be in concentrated form prior to being fed to the substrate. That is, the polishing composition and / or the wetting agent for semiconductors is in the form of a concentrated solution of the polishing solution and / or the rinsing solution, and can also be grasped as a stock solution of the polishing solution and / or the rinsing solution. The polishing composition and / or the wetting agent for semiconductors in such a concentrated form are advantageous from the viewpoints of convenience and cost reduction in manufacturing, distribution, storage and the like. The concentration ratio is not particularly limited, and can be, for example, about 2 to 100 times in terms of volume, and usually about 5 to 50 times (for example, about 10 to 40 times) is appropriate.

(Diluted solution)
The polishing composition and / or semiconductor wetting agent disclosed herein is typically supplied to the substrate in the form of a polishing and rinsing solution containing the polishing composition and / or semiconductor wetting agent. Used for polishing and / or rinsing the substrate. The polishing solution and / or rinsing solution may be prepared by diluting any of the polishing compositions and / or semiconductor wetting agents disclosed herein, for example. The above dilution is typically a dilution with water. Alternatively, the polishing composition and / or the semiconductor wetting agent may be used as it is as a polishing liquid and / or a rinsing liquid. That is, the concept of a polishing composition and / or a wetting agent for semiconductors in the techniques disclosed herein includes a polishing liquid (working slurry) and / or a working slurry supplied to a substrate and used for polishing and / or rinsing the substrate. Both the rinsing solution and the concentrated solution diluted and used as the polishing solution and / or the rinsing solution, that is, the undiluted solution of the polishing solution and / or the rinsing solution are included. Other examples of the polishing solution and / or the rinsing solution containing the polishing composition and / or the semiconductor wetting agent disclosed herein include a polishing solution and / or a rinsing solution obtained by adjusting the pH of the composition. Be done.

The content of the abrasive grains in the concentrate is not particularly limited, but can be, for example, 50% by mass or less. From the viewpoint of handleability of the concentrate, for example, dispersion stability of the abrasive grains, filterability, etc., the content of the abrasive grains in the concentrate is usually preferably 30% by mass or less, more preferably 20% by mass or less. Yes, more preferably 10% by mass or less. Further, from the viewpoint of convenience and cost reduction in manufacturing, distribution, storage, etc., the content of the abrasive grains can be, for example, 0.5% by mass or more, preferably 1% by mass or more. It is preferably 2% by mass or more, for example, 3% by mass or more. In a preferred embodiment, the content of the abrasive grains may be 4% by mass or more, or 5% by mass or more.

The content of the abrasive grains in the diluted solution is not particularly limited, but can be, for example, 25% by mass or less. From the viewpoint of handleability of the diluted solution (for example, dispersion stability of the abrasive grains), surface quality after polishing, and the like, the content of the abrasive grains in the diluted solution is usually preferably 10% by mass or less, more preferably 5. It is 0% by mass or less, more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less. Further, from the viewpoint of convenience and cost reduction in manufacturing, distribution, storage, etc., the content of the abrasive grains can be, for example, 0.01% by mass or more, preferably 0.1% by mass or more. , More preferably 0.2% by mass or more, for example, 0.5% by mass or more. In a preferred embodiment, the content of the abrasive grains may be 1% by mass or more, or 3% by mass or more.

Such a concentrate can be diluted at a desired timing to prepare a polishing liquid (working slurry) and / or a rinsing liquid, and used in an embodiment in which the polishing liquid and / or the rinsing liquid is supplied to the substrate. The dilution can be performed, for example, by adding water to the concentrate and mixing.

The polishing composition and / or the wetting agent for a semiconductor used in the technique disclosed herein may be a one-drug type or a multi-dose type including a two-dose type. For example, part A containing at least abrasive grains among the constituents of the polishing composition and part B containing at least a part of the remaining components are mixed, and these are mixed and diluted at appropriate timings as necessary. This may be configured to prepare the polishing liquid. Further, by mixing Part A containing a part of the constituent components of the semiconductor wetting agent and Part B containing at least a part of the remaining components, and mixing and diluting these at appropriate timings as necessary. The rinse solution may be configured to be prepared.

(Scouring pad)
The polishing pad used in the polishing and / or rinsing process is not particularly limited. For example, a polishing pad such as a polyurethane foam type, a non-woven fabric type, or a suede type can be used. Each polishing pad may or may not contain abrasive grains. Usually, a polishing pad containing no abrasive grains is preferably used.

(Washing)
Substrates polished and / or rinsed with the polishing composition and / or semiconductor wetting agent according to one embodiment of the invention are typically washed. Cleaning can be performed using a suitable cleaning solution. The cleaning liquid to be used is not particularly limited, and for example, SC-1 cleaning liquid, SC-2 cleaning liquid, etc., which are general in the field of semiconductors and the like, can be used. Examples of the SC-1 cleaning solution include a mixed solution of ammonium hydroxide (NH ₄ OH), hydrogen peroxide (H ₂ O ₂ ) and water (H ₂ O). Examples of the SC-2 cleaning solution include a mixed solution of HCl, H ₂ O ₂ and H ₂ O. The temperature of the cleaning liquid can be, for example, above room temperature and in the range of about 90 ° C. Room temperature is typically about 15 ° C to 25 ° C. From the viewpoint of improving the cleaning effect, a cleaning liquid having a temperature of about 40 ° C. to 85 ° C. can be preferably used.

(Use)
The polishing composition and / or semiconductor wetting agent according to one embodiment of the present invention may be particularly preferably used for polishing and / or rinsing a surface made of silicon, typically for polishing and / or rinsing a silicon wafer. .. A typical example of the silicon wafer referred to here is a silicon single crystal wafer (single crystal silicon wafer), for example, a silicon single crystal wafer obtained by slicing a silicon single crystal ingot. The polishing composition and / or semiconductor wetting agent according to one embodiment of the present invention can be suitably used for polishing and / or rinsing a substrate having a surface made of silicon.

(substrate)
The polishing composition and / or semiconductor wetting agent according to one embodiment of the present invention can be applied to polishing and / or rinsing substrates having various materials and shapes. The material of the substrate is, for example, a metal or semi-metal such as silicon, aluminum, nickel, tungsten, copper, tantalum, titanium, stainless steel, or an alloy thereof; a glassy substance such as quartz glass, aluminosilicate glass, and glassy carbon. It can be a ceramic material such as alumina, silica, sapphire, silicon nitride, tantalum nitride, titanium carbide; a compound semiconductor substrate material such as silicon carbide, gallium nitride, gallium arsenide; a resin material such as a polyimide resin; and the like. Of these, a substrate made of a plurality of materials may be used.

The present invention will be described in more detail with reference to the following examples and comparative examples. However, the technical scope of the present invention is not limited to the following examples. Unless otherwise specified, "%" and "part" mean "% by mass" and "part by mass", respectively.

<Manufacturing of hydroxyethyl cellulose>
[Dissolution step]
By adding 2 parts by mass of each of the following raw material hydroxyethyl cellulose (raw material HEC) to 98 parts by mass of deionized water (DIW) as a solvent so as to have the composition shown in Table 1 below, and mixing and dissolving the mixture. , Each raw material hydroxyethyl cellulose aqueous solution (raw material HEC aqueous solution) was prepared.

(Raw material hydroxyethyl cellulose)
HEC1: Weight average molecular weight (Mw): 3.65 × 10 ^ 5, powder,
HEC2: Weight average molecular weight (Mw): 1.18 × 10 ^ 6, powder,
Here, "10 ^ X" (X is an arbitrary integer) represents 10 ^X. The same applies hereinafter.

The weight average molecular weight (Mw) of HEC1 and HEC2 shows the values obtained according to the method for evaluating the weight average molecular weight (Mw) of hydroxyethyl cellulose described later.

[Collision process]
The raw material HEC aqueous solution obtained in the dissolution step was installed in a jet mill (manufactured by Sugino Machine Limited, trade name: Starburst Lab). Subsequently, the jet mill was operated at the output (pressure) shown in Table 1 below, and the raw material HEC aqueous solutions were made to collide with each other to apply pressure to the raw material HEC aqueous solution. The number of processes was one. The amount of the treated raw material HEC aqueous solution is about 5000 mL, and the treatment liquid flow rate and treatment time are as shown in Table 1 below. The treatment time was determined by dividing the amount of the treated raw material HEC aqueous solution by the treatment liquid flow rate.

The raw material HEC aqueous solution (treated HEC aqueous solution) that had undergone the collision step was recovered, and subsequently, the following evaluation was performed.

<Evaluation of hydroxyethyl cellulose>
≪Weight average molecular weight, number average molecular weight and molecular weight distribution≫
The weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution of hydroxyethyl cellulose in each of the above raw material HEC aqueous solutions and each treated HEC aqueous solution were measured by the GPC method under the following equipment and conditions. The results of using HEC1 as the raw material water-soluble polymer are shown in Table 2 below, and the results of using HEC2 as the raw material water-soluble polymer are shown in Table 3 below.

[GPC measurement conditions]
Measuring device: HLC-8420 GPC manufactured by Tosoh Corporation
Column: TSKgel GMPWXL manufactured by Tosoh Corporation
Molecular Weight Marker: Agilent Technologies Polyethylene Oxide-Polyethylene Glycol Eluent: 0.1M NaNO ₃
Flow velocity: 1.0 ml / min.

For each of the above-mentioned raw material HEC aqueous solution and each hydroxyethyl cellulose in each treated HEC aqueous solution, the GPC elution curve (RI (mV) -elution time (min) curve) obtained by the measurement by the above GPC method was confirmed. The GPC elution curve when HEC1 is used as the raw material water-soluble polymer is shown in FIG. 1, and the GPC elution curve when HEC2 is used as the raw material water-soluble polymer is shown in FIG.

From each of these GPC elution curves, the differential molecular weight distribution curve was confirmed. FIG. 3 shows a differential molecular weight distribution curve when HEC1 is used as the raw material water-soluble polymer, and FIG. 4 shows a differential molecular weight distribution curve when HEC2 is used as the raw material water-soluble polymer. The differential molecular weight distribution curve was created by a general method using the control / analysis software "Eco SEC-WS" used in the GPC measuring device.

<< Selective removal of high molecular weight substances in HEC to be treated >>
The fact that the high molecular weight substance is selectively removed in the aqueous solution containing each of the above-mentioned HECs to be treated is determined by [1] the amount of the high molecular weight substance before and after the collision step, and [2] the amount of the low molecular weight substance before and after the collision step. [3] It was confirmed by measuring the change in the peak top molecular weight (Mp). The results are shown in Table 2 below and Table 3 below.

≪Changes in molecular weight distribution before and after the collision process≫
The values of the molecular weight distribution (Mw / Mn) obtained by the measurement by the GPC method for the hydroxyethyl cellulose in each of the above raw material HEC aqueous solutions and each treated HEC aqueous solution are shown in Table 2 below and Table 3 below. The ratio (%) of Mw / Mn of hydroxyethyl cellulose in each HEC aqueous solution to be treated is also shown in Table 2 and Table 3 below with respect to Mw / Mn of hydroxyethyl cellulose in each raw material HEC aqueous solution.

≪Amount of metal impurities≫
The amount of metal element impurities was confirmed by measuring the metal impurity concentration by inductively coupled plasma (ICP) emission spectrometry for the raw material HEC aqueous solution using HEC1 as the raw material water-soluble polymer and the HEC aqueous solution to be treated. The device used is "ICP-AES (model number: ICPS-8100)" manufactured by Shimadzu Corporation.

≪Filtability≫
100 g of each raw material HEC aqueous solution and each treated HEC aqueous solution were weighed and diluted with deionized water (DIW) to prepare a 1% by mass aqueous solution. The prepared aqueous solution was suction-filtered using a filtration filter (material of filter medium: polyether sulfone membrane, pore size: 0.2 μm). The liquid passing time (min) at this time was measured. Further, 100 g of deionized water (DIW) was also suction-filtered in the same manner, and the liquid passing time (sec) was measured. Here, the liquid passing time is the time from the start of filtration until all the liquid passes through the filtration filter. For suction filtration, the filtration device was manufactured by ULVAC Co., Ltd., an ejector (product name), and MDA-015 (model) were used, and the maximum vacuum pressure at the time of the filtration test was about 0.5 kPa. Then, the ratio of the liquid passing time of the raw material HEC aqueous solution or the treated HEC aqueous solution to the DIW liquid passing time (the liquid passing time of the raw material HEC aqueous solution or the treated HEC aqueous solution (min) / the liquid passing time of DIW (sec)) is set. It was evaluated as a filtration index. The smaller the value of the filtration index, the better the filterability. The results of using HEC1 as a raw material are shown in Table 2 below, and the results of using HEC2 as a raw material are shown in Table 3 below.

From the results in Table 2 above, the hydroxyethyl cellulose according to Examples 1 to 3 obtained through the above-mentioned dissolution step and the collision step is lower than the hydroxyethyl cellulose according to Comparative Example 1 not undergoing the above-mentioned collision step. It was confirmed that the amount of the molecular weight substance was maintained well, the high molecular weight substance was selectively removed, and the filterability of the solution was remarkably excellent.

From the results in Table 3 above, the hydroxyethyl cellulose according to Examples 4 to 6 obtained through the above-mentioned dissolution step and the collision step is lower than the hydroxyethyl cellulose according to Comparative Example 2 not undergoing the above-mentioned collision step. It was confirmed that the amount of the molecular weight substance was maintained well, the high molecular weight substance was selectively removed, and the filterability of the solution was remarkably excellent.

More specifically, it was confirmed that in the hydroxyethyl cellulose according to these examples, Mw / Mn was reduced to 17% to 87%. It can be seen that the molecular weight distribution of hydroxyethyl cellulose was narrowed and hydroxyethyl cellulose having a uniform weight molecular weight was obtained. It was also confirmed that the amount of high molecular weight body was reduced to 36% to 93%. Then, it was confirmed that the change in the amount of the low molecular weight substance was within the range of ± 1%. Furthermore, it was confirmed that the change in peak top molecular weight (Mp) was within the range of ± 5%.

In addition, from the measurement results of the amount of metal impurities, it was confirmed that the amount of metal impurities in the water-soluble polymer to be treated did not increase. It is considered that this result is because the mixing of metal impurities could be avoided by the step of colliding the solutions with each other and applying pressure to the solution as in the example.

<Preparation of polishing composition>
(Examples 1 to 4, Comparative Examples 1 and 2)
The above-mentioned HEC aqueous solution to be treated, abrasive grains, basic compound, arbitrary polymer, surfactant, and deionized water (DIW) were mixed to prepare a concentrated solution of the polishing composition. Colloidal silica having an average primary particle diameter of 27 nm is used as the abrasive grains, 29% aqueous ammonia is used as the basic compound, and the optional polymer has a weight average molecular weight of 70,000 and has not been treated according to the present invention. Polyvinyl alcohol was used, and a block copolymer of EO and PO (PEO-PPO-PEO type triblock copolymer) was used as a surfactant. Each polishing composition was obtained by diluting the obtained concentrated solution of the polishing composition with deionized water (DIW) at a volume ratio of 20 times. The concentration of each component in the concentrate of the polishing composition is 0.17 parts by mass of HEC, 3.5 parts by mass of abrasive grains, 0.1 part by mass of basic compound, 0.001 part by mass of arbitrary polymer, and 0 part of surfactant. .025 parts by mass. The concentration of the abrasive grains in the diluted solution of the polishing composition is 0.175% by mass, and the concentration of HEC is 0.0085% by mass.

<Evaluation of polishing composition>
≪Measurement of D90≫
D90 was measured for the particles present in the polishing composition according to this example. UPA-UT151 manufactured by Nikkiso Co., Ltd. was used for the measurement. The results of using HEC1 as the raw material water-soluble polymer are shown in Table 4 below, and the results of using HEC2 as the raw material water-soluble polymer are shown in Table 5 below.

≪polishing test≫
A single crystal silicon wafer with a diameter of 12 inches (conduction type: P type, crystal orientation: <100>, resistivity: 0.1 Ω · cm or more and less than 100 Ω · cm) was prepared and pre-polished under the following pre-polishing conditions. Later, the main polishing was performed.

[Preliminary polishing]
For the polishing liquid used for pre-polishing, the concentrated liquid of the composition prepared by mixing the abrasive grains, the basic compound and the deionized water (DIW) is diluted 20 times by volume with the deionized water (DIW). Obtained by. Colloidal silica having an average primary particle diameter of 42 nm was used as the abrasive grains, and potassium hydroxide was used as the basic compound. The concentration of the abrasive grains in the diluted polishing liquid was 1.0% by mass, and the concentration of the basic compound was 0.068% by mass.

[Preliminary polishing conditions]
Polishing equipment: Single-wafer polishing machine manufactured by Okamoto Machine Tool Mfg. Co., Ltd., model "PNX-332B"
Polishing load: 20 kPa
Surface plate rotation speed: 20 rpm
Head rotation speed: 20 rpm
Polishing pad: Made by Fujibo Ehime, product name "FP55"
Polishing time: 100 seconds Polishing liquid temperature: 20 ° C
Abrasive liquid supply speed: 2.0 liters / minute (using flowing water).

[Main polishing]
The polishing composition according to each example prepared above was used as a polishing liquid, and the silicon wafer obtained through the above pre-polishing was polished under the following polishing conditions.

[Main polishing conditions]
Polishing equipment: Single-wafer polishing machine manufactured by Okamoto Machine Tool Mfg. Co., Ltd., model "PNX-332B"
Polishing load: 15kPa
Surface plate rotation speed: 30 rpm
Head rotation speed: 30 rpm
Polishing pad: Made by Fujibo Ehime, product name "POLYPAS27NX"
Polishing time: 4 minutes Polishing liquid temperature: 20 ° C
Abrasive liquid supply speed: 2.0 liters / minute (using flowing water).

≪LPD-N number measurement≫
The number of LPD-Ns present on the surface (polished surface) of the silicon wafer obtained by the above polishing is measured by using a wafer inspection device manufactured by KLA Tencor Co., Ltd., trade name "SURFSCAN SP2", and the DCO of the device. Measured in mode.

≪Measurement of LPD number≫
The number of LPDs existing on the surface (polished surface) of the silicon wafer obtained by the above polishing can be measured in the DCO mode of the wafer inspection device manufactured by KLA Tencor, trade name "SURFSCAN SP2". Measured.

The evaluation results of LPD-N and LPD are shown in Table 4 below and Table 5 below, respectively. The values of LPD-N and LPD in Tables 4 and 5 below are relative values when the values of LPD-N and LPD of Comparative Examples 1 and 2, respectively are set to 100%.

From the results of Table 4 and Table 5, it was confirmed that the value of D90 of the polishing composition according to the example was reduced. It is considered that this is because the amount of the high molecular weight body of the raw material water-soluble polymer contained in the polishing composition was reduced and / or the diameter of the molecular chain of the high molecular weight body was reduced. In general, the larger the weight molecular weight of a polymer, the easier it is to be adsorbed on the abrasive grains, and the abrasive grains are further adsorbed on the adsorbed water-soluble polymer to form coarse particles. In the polishing composition according to the example, the high molecular weight body of the raw material water-soluble polymer, which may be the cause of producing coarse particles as described above, was removed, so that the D90 of the polishing composition containing the water-soluble polymer was reduced. It is probable that it was done.

Further, from the results of Table 4 and Table 5, when the polishing composition containing the water-soluble polymer obtained through the collision step is used, the polishing composition containing the water-soluble polymer not undergoing the collision step is used. It was confirmed that the amount of LPD-N and LPD was significantly smaller than that of the product.

Further, as described above, it has been confirmed that the hydroxyethyl cellulose according to the examples suppresses the increase of metal impurities. Therefore, even in the polishing composition prepared by using hydroxyethyl cellulose according to such an example or an aqueous solution containing the same, it is possible to prevent an increase in the number and size of coarse particles and the amount of metal impurities. It is also considered that the amount of surface defects caused by this was reduced.

Claims (17)

A polishing composition containing abrasive grains and a water-soluble polymer.
The water-soluble polymer is
The process of dissolving a water-soluble polymer as a raw material in a solvent to make a solution,
The step of colliding the solutions with each other and applying pressure to the solutions,
A polishing composition, which is a water-soluble polymer treated by a method comprising. The polishing composition according to claim 1, wherein the step of applying pressure to the solution is a step of performing a jet mill treatment. A method for producing a polishing composition containing abrasive grains and a water-soluble polymer.
The process of dissolving a water-soluble polymer as a raw material in a solvent to make a solution,
The step of colliding the solutions with each other and applying pressure to the solutions,
The process of mixing the abrasive grains with the pressured solution, and
A method for producing a composition for polishing, including. The method for producing a polishing composition according to claim 3, wherein the step of applying pressure to the solution is a step of performing a jet mill treatment. The method for producing a polishing composition according to claim 3 or 4, further comprising a step of filtering the solution after the step of applying pressure to the solution and before the step of mixing the abrasive grains with the solution. The method for producing a polishing composition according to any one of claims 3 to 5, further comprising a step of filtering the solution after the step of mixing the abrasive grains with the solution. A wetting agent for semiconductors containing a water-soluble polymer,
The water-soluble polymer is
The process of dissolving a water-soluble polymer as a raw material in a solvent to make a solution,
The step of colliding the solutions with each other and applying pressure to the solutions,
A wetting agent for semiconductors, which is a water-soluble polymer treated by a method comprising. The semiconductor wetting agent according to claim 7, wherein the step of applying pressure to the solution is a step of performing a jet mill treatment. A method for manufacturing a wetting agent for semiconductors containing a water-soluble polymer.
The process of dissolving a water-soluble polymer as a raw material in a solvent to make a solution,
The step of colliding the solutions with each other and applying pressure to the solutions,
The step of mixing other components with the pressured solution, and
A method for manufacturing a wetting agent for semiconductors, including. The method for producing a wetting agent for a semiconductor according to claim 9, wherein the step of applying pressure to the solution is a step of performing a jet mill treatment. A method for treating a water-soluble polymer used in the production method according to any one of claims 3 to 6, 9, or 10.
The process of dissolving a water-soluble polymer as a raw material in a solvent to make a solution,
The step of colliding the solutions with each other and applying pressure to the solutions,
A method for treating a water-soluble polymer, including. The process of dissolving a water-soluble polymer as a raw material in a solvent to make a solution,
The step of colliding the solutions with each other and applying pressure to the solutions,
A water-soluble polymer for polishing compositions and / or semiconductor wetting agents, treated by a method comprising: The water-soluble polymer according to claim 12, wherein the step of applying pressure to the solution is a step of performing a jet mill treatment. A method for polishing a substrate using the polishing composition according to claim 1 or 2. A method for rinsing a substrate using the semiconductor wetting agent according to claim 7. The method according to claim 14, wherein the substrate is a single crystal silicon wafer. 15. The method of claim 15, wherein the substrate is a single crystal silicon wafer.

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