Method for producing a semiconductor wetting agent containing a polyvinyl alcohol composition, polishing composition containing a semiconductor wetting agent obtained by the method, and method for producing a polishing composition

Abstract

Provided is a polyvinyl alcohol composition in which the generation of aggregates is effectively suppressed in a method for producing a semiconductor wetting agent containing the polyvinyl alcohol composition. A method for producing a semiconductor wetting agent containing a polyvinyl alcohol composition, the polyvinyl alcohol composition being obtained by a liquid-internal addition process in which either of a first liquid containing a polyvinyl alcohol and water and a second liquid other than the first liquid is internally added with the other of the first liquid and the second liquid.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a semiconductor wetting agent containing a polyvinyl alcohol composition, a polishing composition containing a semiconductor wetting agent obtained by the same method, and a method for manufacturing the polishing composition. Background Technology

[0002] Polyvinyl alcohol is a hydrophilic synthetic resin, and it is mostly used as a fluid solution (aqueous solution) as a fiber raw material, paste, coating, adhesive, emulsifier, etc.

[0003] It is generally known that polyvinyl alcohol (PVA) dispersed in water can dissolve in water by stirring the dispersion at high temperatures (e.g., above 80°C). However, if the dispersion does not dissolve completely in water, lumps (spherical objects) are formed. The formation of these lumps is believed to be due to the surface swelling of the PVA particles in contact with water, resulting in a semi-dissolved state. These semi-dissolved PVA particles then adhere to each other, forming large lumps. These lumps are characterized by only surface dissolution, with no water permeation within, making them extremely difficult to dissolve in solvents. Therefore, PVA aqueous solutions containing lumps present a problem in terms of applicability to various applications.

[0004] To address this problem, various methods for manufacturing aqueous solutions of polyvinyl alcohol have been proposed. For example, Patent Document 1 discloses a method that improves the dispersibility and solubility of polyvinyl alcohol by including a surfactant in it.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2019-94431 Summary of the Invention

[0008] The problem the invention aims to solve

[0009] However, it has been found that even when a polyvinyl alcohol aqueous solution without lumps is obtained, adding other aqueous solutions to the polyvinyl alcohol aqueous solution will produce aggregates. For example, when this polyvinyl alcohol aqueous solution is used as a wetting agent for semiconductors or in abrasive compositions, the aggregates and other solids damage the workpiece being abraded, thus requiring pre-removal of solids through filtration or other means. Polyvinyl alcohol aqueous solutions containing aggregates have very poor filterability, resulting in a significant decrease in productivity, such as longer filtration times or lower yield.

[0010] Therefore, the object of the present invention is to provide a polyvinyl alcohol composition in which the formation of aggregates is effectively suppressed in a method for manufacturing a semiconductor wetting agent containing a polyvinyl alcohol composition (aqueous solution of polyvinyl alcohol).

[0011] Solution for solving the problem

[0012] To solve the aforementioned new problems, the inventors conducted repeated and in-depth research. As a result, they discovered that the above problems were solved by the following method for manufacturing a semiconductor wetting agent and / or polishing composition, thereby completing the present invention. The method for manufacturing the semiconductor wetting agent and / or polishing composition is a method for manufacturing a semiconductor wetting agent and / or polishing composition containing a polyvinyl alcohol composition, wherein the aforementioned polyvinyl alcohol composition is obtained through the following liquid addition step: adding either the aforementioned first liquid or the aforementioned second liquid to a liquid containing either a first liquid and water, or a second liquid other than the aforementioned first liquid.

[0013] The effects of the invention

[0014] According to the present invention, a polyvinyl alcohol composition is provided in which the formation of aggregates is effectively suppressed in a method for manufacturing a semiconductor wetting agent and / or a polishing composition containing a polyvinyl alcohol composition. Attached Figure Description

[0015] Figure 1 A diagram illustrating the apparatus used in experiments involving the addition of liquid. Detailed Implementation

[0016] This invention relates to a method for manufacturing a semiconductor wetting agent and / or polishing composition, specifically a method for manufacturing a semiconductor wetting agent and / or polishing composition containing a polyvinyl alcohol (PVA) composition. The PVA composition is obtained through a liquid addition step: adding either the first liquid or the second liquid to a liquid containing either PVA or water, or a second liquid other than the first liquid. The semiconductor wetting agent and / or polishing composition containing the PVA composition obtained using this manufacturing method exhibits suppressed agglomeration and excellent filterability. According to one embodiment, the semiconductor wetting agent and / or polishing composition containing the PVA composition obtained using this manufacturing method possesses excellent storage stability.

[0017] The mechanism by which this effect is achieved is believed to be as described below. However, the following mechanism is merely speculation, and the scope of the present invention is not limited thereto. In the manufacturing method of the present invention, a second liquid is added to a first liquid containing polyvinyl alcohol, or a first liquid containing polyvinyl alcohol is added to a second liquid. It is believed that this can suppress the formation of bubbles on the liquid surface during the addition of the liquid, and can suppress the formation of aggregates of dried matter caused by these bubbles.

[0018] It should be noted that, in this instruction manual, "liquid addition" refers to the direct addition of one liquid to another, such as introducing a supply tube into one liquid or supplying another liquid to one liquid through a supply tube. It should also be noted that liquid addition does not refer to adding the liquid onto the surface; any method that allows direct addition to the liquid is acceptable and is not limited to the methods described above.

[0019] The embodiments of the present invention will be described below. It should be noted that the present invention is not limited to the embodiments described below. In this specification, the range “X~Y” refers to “X or more and Y or less”, and “weight” and “mass”, “weight%” and “mass%”, and “parts by weight” and “parts by weight” are treated as synonyms. Furthermore, in this specification, unless otherwise specified, the operation and determination of physical properties are performed under conditions of room temperature (20°C or higher and 25°C or lower) and relative humidity (RH) of 40% or higher and 50% or lower.

[0020] Method for manufacturing polyvinyl alcohol compositions

[0021] First, the method for manufacturing the polyvinyl alcohol composition used in the semiconductor wetting agent and / or polishing composition of the present invention will be described. It should be noted that the method for manufacturing the polyvinyl alcohol composition described herein can be directly applied as the method for manufacturing the semiconductor wetting agent and / or polishing composition of the present invention. That is, in the present invention, when the polyvinyl alcohol composition does not contain abrasive particles, the method for manufacturing the polyvinyl alcohol composition can be applied as the method for manufacturing a semiconductor wetting agent containing a polyvinyl alcohol composition. Alternatively, the polyvinyl alcohol composition can also be used directly as a semiconductor wetting agent. In the present invention, when the polyvinyl alcohol composition contains abrasive particles, the method for manufacturing the polyvinyl alcohol composition can be applied as the method for manufacturing a polishing composition containing a polyvinyl alcohol composition. Alternatively, the polyvinyl alcohol composition can also be used directly as a polishing composition. Therefore, according to an embodiment of the present invention, the method for manufacturing the semiconductor wetting agent and / or polishing composition containing a polyvinyl alcohol composition is also renamed the method for manufacturing the semiconductor wetting agent and / or polishing composition containing polyvinyl alcohol.

[0022] In the polyvinyl alcohol composition of the present invention, the mixing step of mixing a first liquid containing polyvinyl alcohol and water and a second liquid other than the first liquid to obtain the polyvinyl alcohol composition includes a liquid addition step in which the other liquid is added to either the first liquid or the second liquid.

[0023] [First Liquid]

[0024] The first liquid contains polyvinyl alcohol and water. The first liquid may also contain, as needed, known additives such as surfactants, water-soluble polymers other than polyvinyl alcohol, chelating agents, organic acids, organic acid salts, inorganic acids, inorganic acid salts, pH adjusters, oxidants, metal corrosion inhibitors, preservatives, and fungicides, as well as solvents other than water.

[0025] (Polyvinyl alcohol)

[0026] In this invention, polyvinyl alcohol may contain only vinyl alcohol units (hereinafter also referred to as "VA units") as repeating units, or it may contain repeating units other than VA units (hereinafter also referred to as "non-VA units"). A vinyl alcohol unit refers to the structural part represented by the chemical formula: -CH2-CH(OH)-. Polyvinyl alcohol may also be a random copolymer, block copolymer, alternating copolymer, or graft copolymer containing VA units and non-VA units. Polyvinyl alcohol may contain only one type of non-VA unit, or it may contain two or more types of non-VA units.

[0027] Polyvinyl alcohol can be either unmodified polyvinyl alcohol (non-modified PVA) or modified polyvinyl alcohol (modified PVA). Here, unmodified PVA refers to polyvinyl alcohol that is generated by hydrolyzing (saponifying) polyvinyl acetate and does not substantially contain repeating units other than the repeating units (-CH2-CH(OCOCH3)-) and VA units of the structure formed by polymerizing vinyl acetate.

[0028] The degree of saponification of unmodified PVA is preferably 70 mol% or more, more preferably 80 mol% or more, and even more preferably 90 mol% or more. Particularly in applications involving grinding compositions, the degree of saponification of unmodified PVA is preferably 95 mol% or more, more preferably 98 mol% or more, and even more preferably 99.3% or more. Therefore, according to one embodiment of the present invention, unmodified PVA with a saponification degree of 95 mol% or more (preferably 98 mol% or more, more preferably 99.3 mol% or more) is preferably used. PVA with a high degree of saponification tends to more easily form lumps, thus the present invention can be suitably used. In this specification, the degree of saponification is a value determined according to JIS-K6726 (1994). Specifically, the degree of saponification refers to the ratio of acetoxy groups (-OCOCH3) in polyvinyl acetate to hydroxyl groups (-OH), specifically expressed as a percentage of the number of hydroxyl groups relative to the total number of acetoxy groups and hydroxyl groups in polyvinyl alcohol.

[0029] Examples of non-VA units that can be included in modified PVA include, but are not limited to, repeating units derived from N-vinyl type monomers (described later), repeating units derived from N-(meth)acryloyl type monomers, repeating units derived from ethylene, repeating units derived from alkyl vinyl ethers, and repeating units derived from vinyl esters of monocarboxylic acids having 3 or more carbon atoms. A preferred example of the aforementioned N-vinyl type monomer is N-vinylpyrrolidone. A preferred example of the aforementioned N-(meth)acryloyl type monomer is N-(meth)acryloylmorpholine. Examples of the aforementioned alkyl vinyl ethers include, for example, propyl vinyl ether, butyl vinyl ether, 2-ethylhexyl vinyl ether, and other vinyl ethers having an alkyl group having 1 or more and 10 or less carbon atoms. Examples of the aforementioned vinyl esters of monocarboxylic acids having 3 or more carbon atoms include, for example, vinyl propionate, vinyl butyrate, vinyl valerate, vinyl hexanoate, and other vinyl esters of monocarboxylic acids having 3 or more and 7 or less carbon atoms.

[0030] Alternatively, polyvinyl alcohol can also be a modified PVA formed by acetalizing a portion of the VA unit contained in polyvinyl alcohol. As the aldehyde, alkyl aldehydes are preferred, especially alkyl aldehydes having an alkyl group having 1 or more and 7 or fewer carbon atoms, with acetaldehyde, n-propionaldehyde, n-butyraldehyde, and n-pentanaldehyde being preferred. As the polyvinyl alcohol, cationic modified polyvinyl alcohol with cationic groups such as quaternary ammonium structures can be used. Examples of cationic modified polyvinyl alcohol include, for instance, cationic modified polyvinyl alcohol with cationic groups derived from monomers having cationic groups such as diallyl dialkylammonium salt or N-(meth)acryloylaminoalkyl-N,N,N-trialkylammonium salt.

[0031] In addition, polyvinyl alcohol can also be a modified PVA containing VA units and non-VA units having at least one structure selected from alkylene oxide, carboxyl, sulfonyl, amino, hydroxyl, amide, imide, nitrile, ether, ester and their salts.

[0032] The percentage of VA units in the total number of repeating units constituting polyvinyl alcohol can be, for example, 5% or more, 10% or more, 20% or more, or 30% or more. While not particularly limited, in several embodiments, the percentage of VA units can be 50% or more, 65% or more, 75% or more, 80% or more, or 90% or more (e.g., 95% or more, or 98% or more). It is also possible for the repeating units constituting polyvinyl alcohol to be substantially 100% VA units. Here, "substantially 100%" means that non-VA units are intentionally not present in the polyvinyl alcohol, typically in cases where the percentage of non-VA units in the total number of repeating units is less than 2% (e.g., less than 1%) or 0%. In other embodiments, the percentage of VA units in the total number of repeating units constituting polyvinyl alcohol can be, for example, less than 95%, less than 90%, less than 80%, or less than 70%.

[0033] The content of VA units in polyvinyl alcohol (based on mass) can be, for example, 5% by mass or more, 10% by mass or more, 20% by mass or more, or 30% by mass or more. While not specifically limited, in several embodiments, the content of VA units can be 50% by mass or more (e.g., more than 50% by mass), 70% by mass or more, or 80% by mass or more (e.g., 90% by mass or more, or 95% by mass or more, or 98% by mass or more). It is also possible for substantially 100% by mass of the repeating units constituting polyvinyl alcohol to be VA units. Here, "substantially 100% by mass" means that, at least intentionally, non-VA units are not present as repeating units constituting polyvinyl alcohol; typically, it means that the content of non-VA units in polyvinyl alcohol is less than 2% by mass (e.g., less than 1% by mass). In other embodiments, the content of VA units in polyvinyl alcohol can be, for example, less than 95% by mass, less than 90% by mass, less than 80% by mass, or less than 70% by mass.

[0034] Polyvinyl alcohol can contain multiple polymer chains with varying amounts of VA units within the same molecule. Here, a polymer chain refers to a segment (chain segment) that constitutes a part of a polymer molecule. For example, polyvinyl alcohol can contain polymer chain A, which has a VA unit content of more than 50% by mass, and polymer chain B, which has a VA unit content of less than 50% by mass (i.e., a non-VA unit content of more than 50% by mass).

[0035] Polymer chain A may contain only VA units as repeating units, or it may contain non-VA units in addition to VA units. The content of VA units in 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 several cases, the content of VA units in polymer chain A may be 95% by mass or more, or 98% by mass or more. Alternatively, the repeating units constituting polymer chain A may substantially be 100% by mass of VA units.

[0036] Polymer chain B may contain only non-VA units as repeating units, or it may contain VA units in addition to non-VA units. The content of non-VA units in 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 several cases, the content of non-VA units in polymer chain B may be 95% by mass or more, or 98% by mass or more. Alternatively, the repeating units constituting polymer chain B may substantially be 100% by mass non-VA units.

[0037] Examples of polyvinyl alcohol containing polymer chain A and polymer chain B in the same molecule include block copolymers and graft copolymers containing these polymer chains. The graft copolymers can be graft copolymers with polymer chain B (side chain) grafted onto polymer chain A (main chain) or graft copolymers with polymer chain A (side chain) grafted onto polymer chain B (main chain). In one embodiment, polyvinyl alcohol with polymer chain B grafted onto polymer chain A can be used.

[0038] Examples of polymer chain B include polymer chains with repeating units derived from N-vinyl monomers as the main repeating units, polymer chains with repeating units derived from N-(meth)acryloyl monomers as the main repeating units, and polymer chains with alkylene oxide units as the main repeating units. It should be noted that, unless otherwise specified, the term "main repeating unit" in this specification refers to repeating units containing more than 50% by mass.

[0039] As a preferred example of polymer chain B, a polymer chain in which N-vinyl monomers are the main repeating units can be cited, i.e., an N-vinyl polymer chain. The content of repeating units derived from N-vinyl monomers in the N-vinyl polymer chain is typically more than 50% by mass, and can be more than 70% by mass, more than 85% by mass, or more than 95% by mass. Alternatively, polymer chain B may be substantially entirely composed of repeating units derived from N-vinyl monomers.

[0040] In this specification, examples of N-vinyl type monomers include monomers having nitrogen-containing heterocyclic rings (e.g., lactam rings) and N-vinyl chain amides. Specific examples of N-vinyl lactam type monomers include N-vinylpyrrolidone, N-vinylpiperidone, N-vinylmorpholinone, N-vinylcaprolactam, N-vinyl-1,3-oxazin-2-one, and N-vinyl-3,5-morpholinedione. Specific examples of N-vinyl chain amides include N-vinylacetamide, N-vinylpropionic acid amide, and N-vinylbutyric acid amide. Polymer chain B can, for example, be an N-vinyl polymer chain in which more than 50% by mass (e.g., more than 70% by mass, or more than 85% by mass, or more than 95% by mass) of its repeating units are N-vinylpyrrolidone units. Alternatively, the repeating units constituting polymer chain B may be substantially entirely N-vinylpyrrolidone units.

[0041] Other examples of polymer chain B include polymer chains in which repeating units derived from N-(meth)acryloyl type monomers are the main repeating units, i.e., N-(meth)acryloyl-based polymer chains. The content of repeating units derived from N-(meth)acryloyl type monomers in N-(meth)acryloyl-based polymer chains is typically more than 50% by mass, and can be more than 70% by mass, more than 85% by mass, or more than 95% by mass. Alternatively, polymer chain B may be substantially entirely composed of repeating units derived from N-(meth)acryloyl type monomers.

[0042] In this specification, 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 include (meth)acrylamide; N-alkyl (meth)acrylamides such as N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, N-isopropyl(meth)acrylamide, and N-n-butyl(meth)acrylamide; and N,N-dialkyl (meth)acrylamides such as N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-dipropyl(meth)acrylamide, N,N-diisopropyl(meth)acrylamide, and N,N-di(n-butyl)(meth)acrylamide. Examples of cyclic amides having an N-(meth)acryloyl group include N-(meth)acryloylmorpholine and N-(meth)acryloylpyrrolidine.

[0043] Other examples of polymer chain B include polymer chains containing alkylene oxide units as the main repeating units, i.e., alkylene oxide-based polymer chains. The content of alkylene oxide units in alkylene oxide-based polymer chains is typically more than 50% by mass, and can be more than 70% by mass, more than 85% by mass, or more than 95% by mass. Alternatively, polymer chain B may contain virtually all repeating units that are alkylene oxide units.

[0044] Examples of alkylene oxide units include ethylene oxide units, propylene oxide units, and butylene oxide units. These alkylene oxide units can be repeating units derived from their corresponding olefin oxides. The alkylene oxide polymer chain may contain one or more alkylene oxide units. For example, it may be an alkylene oxide polymer chain containing both ethylene oxide units and propylene oxide units. In alkylene oxide polymer chains containing two or more alkylene oxide units, these alkylene oxide units may be random copolymers, block copolymers, alternating copolymers, or graft copolymers of their corresponding olefin oxides.

[0045] Other examples of polymer chain B include polymer chains containing alkyl vinyl ether units, structural units obtained by acetalizing polyvinyl alcohol and aldehydes as main repeating units. Among these, the preferred choices are vinyl ether units (alkyl vinyl ether units) having 1 or more and 10 or fewer carbon atoms, vinyl ester units derived from monocarboxylic acids having 1 or more and 7 or fewer carbon atoms (monocarboxylic acid vinyl ester units), and structural units obtained by acetalizing polyvinyl alcohol with alkyl groups having 1 or more and 7 or fewer carbon atoms.

[0046] Examples of vinyl ether units having an alkyl group having 1 or more but less than 10 carbon atoms include propyl vinyl ether units, butyl vinyl ether units, and 2-ethylhexyl vinyl ether units. Examples of vinyl ester units derived from monocarboxylic acids having 1 or more but less than 7 carbon atoms include vinyl propionate units, vinyl butyrate units, vinyl valerate units, and vinyl hexanoate units.

[0047] The polyvinyl alcohol used in the grinding compositions and / or semiconductor wetting agents disclosed herein is preferably unmodified PVA (non-modified PVA).

[0048] There is no particular limitation on the weight-average molecular weight (Mw) of polyvinyl alcohol. The Mw of polyvinyl alcohol is typically 2 × 10⁻⁶. 3 The above, or 5×10 3 The above, or 1×10 4The above is true. As the Mw of polyvinyl alcohol increases, there is a tendency for the wettability of the surface after grinding and / or rinsing to increase. Furthermore, if the Mw of polyvinyl alcohol increases, there is a tendency for the dispersibility of polyvinyl alcohol to decrease, thus increasing the applicability of the present invention. From the above viewpoints, the Mw of polyvinyl alcohol is preferably 3 × 10⁻⁶. 4 Above, or more preferably 4×10 4 The above, further optimized 5×10 4 The above, especially the preferred 6×10 4 The above (e.g., 6.5 × 10) 4 above).

[0049] The weight-average molecular weight (Mw) of polyvinyl alcohol is typically 100 × 10⁻⁶. 4 The following is suitable, preferably 30×10 4 The following can also be 20×10 4 The following (e.g., 15×10) 4 (The following). Considering both grinding speed and substrate surface protection, the Mw of polyvinyl alcohol can be 10 × 10⁻⁶. 4 The following can also be 8×10 4 the following.

[0050] It should be noted that in this specification, the weight-average molecular weight (Mw) refers to the value based on aqueous gel permeation chromatography (GPC) (conversion between aqueous and polyethylene oxide systems). The GPC measuring instrument can be the "HLC-8320GPC" manufactured by TOSOH CORPORATION. The measurement conditions are as follows.

[0051] [GPC Measurement Conditions]

[0052] Sample concentration: 0.1% by mass

[0053] Column: TSKgel GMPWXL

[0054] Detector: Differential refractometer

[0055] Eluent: 100mM sodium nitrate aqueous solution / acetonitrile = 10-8 / 0-2

[0056] Flow rate: 1 mL / min

[0057] Measurement temperature: 40℃

[0058] Sample injection volume: 200 μL.

[0059] The degree of polymerization of polyvinyl alcohol is typically around 100 to 10,000, and is particularly preferred to be 300 or higher, more preferably 500 or higher, and even more preferably 1,500 or higher, specifically 2,000 or higher, in applications involving grinding compositions. Furthermore, the degree of polymerization of polyvinyl alcohol is preferably 4,000 or lower, more preferably 3,000 or lower, and even more preferably 2,900 or lower. When the degree of polymerization is within the above range, the effects of the present invention are fully realized.

[0060] As used in this invention, polyvinyl alcohols such as "PVA-117" (degree of polymerization 1700, degree of saponification 98-99 mol%), "PVA-117H" (degree of polymerization 1700, degree of saponification 99.3 mol% or more), and "PVA-124" (degree of polymerization 2400, degree of saponification 98-99 mol%), manufactured by Kuraray Co., Ltd., are available in powder form.

[0061] The lower limit of the polyvinyl alcohol content in the first liquid relative to the total mass of the first liquid is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more. Furthermore, the upper limit of the polyvinyl alcohol content in the first liquid is preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less. That is, the polyvinyl alcohol content is preferably 0.05 to 10% by mass, more preferably 0.1 to 7% by mass, and even more preferably 0.5 to 5% by mass. The effects of the present invention are fully realized when the polyvinyl alcohol content is within the above range.

[0062] (water)

[0063] Water serves as a solvent for polyvinyl alcohol. The water is preferably as free of impurities as possible. Preferably, this water is obtained by removing impurity ions using an ion exchange resin, removing impurities using a filter, or removing foreign matter by distillation. Examples of such water include ion-exchanged water, pure water, ultrapure water, and distilled water. To minimize the suppression of the effects of other components contained in the semiconductor wetting agent and / or grinding composition, for example, the total content of transition metal ions is preferably 100 ppb or less.

[0064] The water content relative to the total mass of the first liquid is preferably 90% by mass or more, more preferably 93% by mass or more, and even more preferably 95% by mass or more. Furthermore, as an upper limit for the water content relative to the total mass of the first liquid, it is preferably 99.95% by mass or less, more preferably 99.9% by mass or less, and even more preferably 99.5% by mass or less. That is, the water content relative to the total mass of the first liquid is preferably 90 to 99.95% by mass, more preferably 93 to 99.9% by mass, and even more preferably 95 to 99.5% by mass. If the water content is within the above range, the effects of the present invention are fully realized.

[0065] (Method for manufacturing the first liquid)

[0066] There are no particular limitations on the method for manufacturing the first liquid having the above-described structure; for example, a method including steps A and B described below can be listed.

[0067] Process A: A dispersion process that disperses polyvinyl alcohol in water to obtain a polyvinyl alcohol dispersion.

[0068] Step B: The dissolution step of the first liquid is obtained by heating the polyvinyl alcohol dispersion to above 80°C and stirring it to dissolve the polyvinyl alcohol in water.

[0069] It should be noted that, in this invention, the state of polyvinyl alcohol dispersed in water refers to the state in which polyvinyl alcohol powder exists unevenly or uniformly in water, and the state of polyvinyl alcohol dissolved in water refers to the state in which polyvinyl alcohol and water are mixed, the polyvinyl alcohol powder cannot be visually identified in the solution, and a uniform solution is formed.

[0070] Process A: Decentralized Process

[0071] The water temperature for dispersing polyvinyl alcohol in water is preferably 15°C or higher, more preferably 20°C or higher. Furthermore, the water temperature for dispersing polyvinyl alcohol in water is preferably 25°C or lower. If the water temperature is within the above range, the formation of lumps in the polyvinyl alcohol in the water can be suppressed, and therefore this is preferable.

[0072] The polyvinyl alcohol content in the polyvinyl alcohol dispersion is the same as the polyvinyl alcohol content in the first liquid obtained after the dispersion process and the dissolution process. If the polyvinyl alcohol content is within the above range, the polyvinyl alcohol dispersion can be effectively manufactured, and this is therefore preferred.

[0073] When dispersing polyvinyl alcohol in water, stirring is preferred. For example, in the dispersion process, it is preferred to carry out the process in a stirring container attached to a mixer.

[0074] The dispersion process is preferably completed with the polyvinyl alcohol forming a uniform dispersion as a baseline, and then proceeds to the next dissolution process.

[0075] • Process B: Dissolving process

[0076] In this specification, the dissolution process refers to the period during which the temperature of the water used to dissolve polyvinyl alcohol (PVA) exceeds 80°C. The water temperature used to dissolve PVA is preferably 85°C or higher, more preferably 88°C or higher, and even more preferably 90°C or higher. Furthermore, the water temperature used to dissolve PVA is preferably 98°C or lower, more preferably 96°C or lower, and even more preferably 94°C or lower. If the water temperature is within the above range, the PVA is fully dissolved in the water, and a homogeneous aqueous solution of PVA (first liquid) can be obtained, which is therefore preferred.

[0077] The polyvinyl alcohol content in the first liquid obtained through the dissolution process is as described above.

[0078] When dissolving polyvinyl alcohol in water, stirring is preferred. The stirring time (i.e., the time required for polyvinyl alcohol to dissolve in water) is preferably 10 minutes or more, more preferably 20 minutes or more. Furthermore, the stirring time is preferably 300 minutes or less, more preferably 200 minutes or less, and even more preferably 100 minutes or less. For example, the stirring time can be set to 80 minutes or less, 60 minutes or less, or 30 minutes or less.

[0079] The dissolution process ends with polyvinyl alcohol reaching a uniform dissolved state. The resulting first liquid is preferably cooled to 15–50°C (preferably 20–35°C, for example 25–28°C) before proceeding to the next process. Cooling can be achieved using an apparatus or by natural heat release. Alternatively, it can be air cooling or liquid cooling (e.g., water cooling), and the type of heat exchange medium is not limited. As one embodiment, the first liquid is cooled at a rate preferably 1–10°C / min, more preferably 1–5°C / min, and even more preferably 1–4°C / min. This ensures that the polyvinyl alcohol remains uniformly dissolved in the first liquid.

[0080] According to one embodiment of the present invention, the first liquid is preferably manufactured through steps A and B. Thus, according to a preferred embodiment of the present invention, the first liquid is obtained by heating a polyvinyl alcohol dispersion in water to 85–98°C and then cooling it to 15–50°C. Therefore, in the first liquid, polyvinyl alcohol readily forms a uniform dissolved state, resulting in a polyvinyl alcohol composition with reduced aggregate formation.

[0081] (additive)

[0082] The first liquid may contain known additives as described above. There are no particular restrictions on the additives, but it is preferable to add them after dissolving polyvinyl alcohol in water.

[0083] [Second Liquid]

[0084] The second liquid contains a solvent. The second liquid may also contain, as needed, known additives such as abrasive particles, surfactants, water-soluble polymers, thickeners, pH adjusters, complexing agents, preservatives, and fungicides. Here, the second liquid may be, for example, only a solvent, or it may be a solution containing polyvinyl alcohol and a solvent. Therefore, in one embodiment of the present invention, it may be a mixture of a first liquid containing polyvinyl alcohol and water (the second liquid), or it may be a mixture of a first liquid containing polyvinyl alcohol and a second liquid containing polyvinyl alcohol.

[0085] The second liquid may contain polyvinyl alcohol (PVA). In this case, the second liquid contains a solvent and PVA. When the second liquid contains PVA, the lower limit of the PVA content in the second liquid relative to the total mass of the second liquid is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more. Furthermore, the upper limit of the PVA content in the second liquid is preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less.

[0086] The second liquid may contain abrasive particles. In this case, the second liquid contains a solvent and abrasive particles. In one embodiment, the second liquid contains a solvent, abrasive particles, and polyvinyl alcohol. When the second liquid contains abrasive particles, the lower limit of the abrasive particle content in the second liquid relative to the total mass of the second liquid is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 5% by mass or more. Furthermore, the upper limit of the abrasive particle content in the second liquid is preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 60% by mass or less.

[0087] In one embodiment, the second liquid contains a solvent, abrasive particles, and polyvinyl alcohol. In this case, the amounts of abrasive particles and polyvinyl alcohol in the second liquid can be as described above.

[0088] (solvent)

[0089] Examples of solvents contained in the second liquid include water; alcohols such as methanol, ethanol, and ethylene glycol; ketones such as acetone; and mixtures thereof. Among these, water is preferred as the solvent. That is, in the preferred embodiment of the present invention, the solvent in the second liquid contains water. In the more preferred embodiment of the present invention, the solvent in the second liquid is substantially composed of water. It should be noted that the phrase "substantially" above is intended to mean that the liquid can contain solvents other than water, as long as the objective effect of the present invention can be achieved. More specifically, it is preferred to contain solvents other than water, which are 90% by mass or more and 100% by mass or less, and 0% by mass or more and 10% by mass or less; more preferably, it contains solvents other than water, which are 99% by mass or more and 100% by mass or less, and 0% by mass or more and 1% by mass or less; and even more preferably, it contains solvents other than water, which are 99.5% by mass or more and 100% by mass or less, and 0% by mass or more and 0.5% by mass or less. The most preferred solvent is water.

[0090] When using polyvinyl alcohol compositions as wetting agents and / or polishing compositions for semiconductors, the effect of the components contained in the wetting agents and / or polishing compositions for semiconductors is never suppressed. Therefore, the solvent used as the second liquid is preferably water that is as free of impurities as possible. More specifically, it is more preferably pure water, ultrapure water, or distilled water obtained by removing impurity ions using an ion exchange resin and then removing foreign matter by a filter.

[0091] The solvent content relative to the total mass of the second liquid is preferably 90% by mass or more, more preferably 93% by mass or more, and even more preferably 95% by mass or more. Furthermore, as an upper limit for the solvent content relative to the total mass of the second liquid, it is preferably 100% by mass or less, more preferably 99.9% by mass or less, and even more preferably 99.5% by mass or less. That is, the solvent content relative to the total mass of the second liquid is preferably 90 to 100% by mass, more preferably 93 to 99.9% by mass, and even more preferably 95 to 99.5% by mass.

[0092] [Liquid Addition Process]

[0093] In this invention, the mixing step of mixing a first liquid containing polyvinyl alcohol and water, and a second liquid other than the first liquid, to obtain a polyvinyl alcohol composition includes a liquid addition step in which either the first liquid or the second liquid is added to a solution of either the first liquid or the second liquid. That is, the manufacturing method of this invention is characterized in that, in the mixing step of mixing the first liquid and the second liquid, a liquid addition step is included in which either the first liquid or the second liquid is added to a solution of either the first liquid or the second liquid.

[0094] In the liquid addition process, the second liquid can be added to the first liquid, or the first liquid can be added to the second liquid. There are no particular limitations on the method of liquid addition; for example, a method using a supply pipe can be employed. Specifically, one end of the supply pipe is placed in either the first or second liquid (which serves as the supply side), and the other end of the supply pipe is placed in either the first or second liquid (which serves as the supply side). A pump, such as an air pump, is then used to add either the first or second liquid (which serves as the supply side) to the other liquid (which serves as the supply side) via the supply pipe.

[0095] According to one embodiment of the present invention, it is preferable to add the first liquid to the second liquid. This allows the polyvinyl alcohol in the first liquid to mix with the second liquid without contacting air, further inhibiting the formation of polyvinyl alcohol lumps.

[0096] At this point, there are no particular restrictions on the size of the supply pipe, but it is preferable that the diameter (inner diameter) of the supply pipe is less than 50 cm. If such a supply pipe is used, it will not affect the liquid surface, and the liquid can be added internally in an effective manner.

[0097] The supply rate for adding the liquid is not particularly limited, but it is preferably low enough to avoid the formation of lumps due to the collision of polyvinyl alcohol particles. Preferably, it is 50 mL / min or more, more preferably 100 mL / min or more, and even more preferably 120 mL / min or more. Furthermore, the supply rate for adding the liquid is preferably 20 L / min or less. At this supply rate, there is no impact on the liquid surface, allowing for efficient addition of the liquid.

[0098] Either the first liquid or the second liquid on the supply side is preferably held in a container equipped with a stirring unit. This allows for simultaneous addition and stirring of the liquid. According to one embodiment of the invention, the first liquid is added to the second liquid held in the container equipped with the stirring unit. Examples of containers equipped with the stirring unit include, for instance, vertical and horizontal stirring containers.

[0099] A vertical mixing vessel refers to a vessel having a vertical rotating shaft and mixing blades mounted on that shaft. Examples of mixing blade types include propeller blades, turbine blades, paddle blades, three-bladed swept blades, anchor blades, FULLZONE blades (manufactured by SHINKO PANTEC CO.,LTD.), Sun Meller blades (manufactured by Mitsubishi Heavy Industries, Ltd.), MAXBLEND blades (manufactured by Sumitomo Heavy Industries, Ltd.), spiral ribbon blades, and torsion grid blades (manufactured by Hitachi, Ltd.).

[0100] A horizontally mounted mixing vessel refers to a mixing vessel in which multiple mixing blades are mounted on a horizontally positioned (horizontal) rotating shaft. The blades extend approximately perpendicularly to this rotating shaft, and are positioned horizontally offset from each other to prevent collision. Examples of mixing blade types include single-screw blades such as disc and paddle types, and twin-screw blades such as spectacle-shaped and grid-shaped blades (manufactured by Hitachi, Ltd.). Other examples include wheel-shaped, paddle-shaped, rod-shaped, and window-frame-shaped mixing blades.

[0101] There are no particular limitations on the size of the stirring container described above; for example, a size of 0.01m is preferred. 3 Above, more preferably 0.1m 3 Above, further optimization of 1m 3 Containers of the above dimensions. Furthermore, the preferred size of the aforementioned stirring container is 20m. 3 Below, more preferably 10m 3 the following.

[0102] There are no particular restrictions on the material of the mixing vessel. For example, stainless steel is preferred, and even more preferred is a mixing vessel with an inner wall coated with SUS316, glass, Teflon, titanium, etc. The mixing vessel may be equipped with baffles as needed. There are no particular restrictions on the size, shape, or number of baffles.

[0103] There are no particular limitations on the strength or size of the rotating shaft. There are also no limitations on the material of the rotating shaft; for example, stainless steel is preferred, and even more preferred are glass, Teflon, titanium-coated materials, or SUS316 stainless steel.

[0104] There is no particular limitation on the number of stirring blades used; for example, it can be set to 1 to 10 blades, preferably 1 to 5 blades, and more preferably 2 to 5 blades. When using 3 or more stirring blades, there is no limitation on the spacing between the stirring blades in multiple locations, but it is preferable that they are evenly arranged.

[0105] There are no restrictions on the size of the stirring blades. For example, the ratio (L / D) of the stirring blade diameter (L) to the inner diameter (D) of the stirring container is preferably 0.1 or more, more preferably 0.25 or more. Furthermore, L / D is preferably 0.9 or less, more preferably 0.75 or less. It should be noted that "inner diameter of the stirring container" refers to the longest diameter of the stirring container in the direction perpendicular to the rotation axis. For example, in the case of a stirring container formed by a cylindrical portion sandwiched between the upper and lower lid portions (the circular portions of the upper and lower parts of the stirring container), it refers to the diameter within the groove of that cylindrical portion. "Stirring blade diameter" refers to the diameter obtained by measuring twice the longest distance from the center of the rotation axis to the tip of the stirring blade. "Tip of the stirring blade" refers to the furthest part when measured perpendicularly from the rotation axis.

[0106] Furthermore, in the liquid addition process, when viewed in the axial direction, adjacent stirring blades can form any angle with each other. From the viewpoint of effectively stirring, it is preferable to set it to 0 degrees (parallel) or 90 degrees (right angle).

[0107] There are no particular restrictions on the material of the stirring blades. For example, stainless steel is preferred, and glass, Teflon, titanium-coated materials, or SUS316 stainless steel are even more preferred.

[0108] There are no particular restrictions on the atmosphere inside the stirring container during stirring. Examples of suitable atmospheres include air, argon, nitrogen, and other inactive gases. The stirring can be carried out under normal or reduced pressure conditions.

[0109] The temperature of the solution during the liquid addition process is preferably 20°C or higher, more preferably 25°C or higher. Furthermore, the temperature of the solution during the liquid addition process is preferably 80°C or lower, more preferably 60°C or lower. It should be noted that methods for heating the stirring vessel include providing a jacket for the heat medium around the outer periphery of the stirring vessel, heating the solution through heat transfer via the wall of the stirring vessel, or heating through heat transfer via heat transfer using a heat transfer tube (coil) inside the stirring vessel; these methods can be used individually or in combination.

[0110] In the liquid addition process, there is no particular limitation on the rotational speed (i.e., the number of agitations) of the stirring blades in the mixing container on the supply side. Stirring may or may not be performed. If stirring is performed, the rotational speed is preferably 1 rpm or more, depending on the capacity of the mixing container. From the viewpoint of suppressing the formation of polyvinyl alcohol lumps, the rotational speed of the stirring blades is preferably 300 rpm or less, more preferably 200 rpm or less, and even more preferably 100 rpm or less. That is, when stirring is performed in the liquid addition process, the rotational speed of the stirring blades is preferably 1 rpm or more and 300 rpm or less, more preferably 1 rpm or more and 200 rpm or less, and even more preferably 1 rpm or more and 100 rpm or less. If the rotational speed of the stirring blades is within the above range, the vortex caused by stirring will not be too large, and the mixing of gas will be reduced.

[0111] The time for the liquid addition process also depends on the amount of solution on the supply side (addition side), for example, it is preferable to finish the addition in 1 to 30 minutes.

[0112] Here, the mixing ratio of the first liquid to the second liquid, by mass ratio, is preferably 1:99 to 99:1, more preferably 10:90 to 90:10, even more preferably 20:80 to 80:20, and particularly preferably 30:70 to 70:30. For example, the above mass ratio can be set to 20:80 to 40:60 or 80:20 to 60:40.

[0113] The polyvinyl alcohol (PVA) content in the PVA composition obtained in the liquid addition process is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more, relative to the total mass of the PVA composition. Furthermore, the upper limit of the PVA content in the PVA composition obtained in the liquid addition process is preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less. If the PVA content in the PVA composition obtained through the liquid addition process is within the above range, the formation of aggregates can be suppressed, further enhancing the effects of the present invention.

[0114] [Processes following the liquid addition process]

[0115] • Process C: Mixing process

[0116] According to one embodiment of the present invention, a stirring step is included after the liquid addition step, in which the polyvinyl alcohol composition is stirred. This stirring step is preferred because it ensures a uniform dispersion of the polyvinyl alcohol.

[0117] The temperature of the polyvinyl alcohol composition during the stirring process is preferably 20°C or higher, more preferably 23°C or higher, even more preferably 25°C or higher, and even more preferably 30°C or higher. Furthermore, the temperature of the polyvinyl alcohol composition during the stirring process is preferably 80°C or lower, more preferably 60°C or lower.

[0118] In the mixing process, the rotational speed (i.e., the number of agitations) of the stirring blades in the mixing container depends on the capacity of the mixing container, but is preferably 1 rpm or more. Furthermore, from the viewpoint of suppressing the formation of polyvinyl alcohol lumps, the rotational speed of the stirring blades is preferably 300 rpm or less, more preferably 200 rpm or less, and even more preferably 100 rpm or less. That is, in the mixing process after the liquid addition step, the rotational speed of the stirring blades is preferably 1 rpm or more and 300 rpm or less, more preferably 1 rpm or more and 200 rpm or less, and even more preferably 1 rpm or more and 100 rpm or less. If the rotational speed of the stirring blades is within the above range, the vortex caused by mixing will not be too large, and the mixing of gas will be reduced.

[0119] It should be noted that there is no limitation on the size of the stirring blades. For example, the ratio (L / D) of the stirring blade diameter (L) to the inner diameter (D) of the stirring container is preferably 0.1 or more, and more preferably 0.25 or more. In addition, L / D is preferably 0.9 or less, and more preferably 0.75 or less.

[0120] The stirring process can be terminated with the goal of achieving a uniform dispersion of polyvinyl alcohol. For example, the stirring time in the stirring process is preferably 1 minute or more, more preferably 2 minutes or more, and even more preferably 3 minutes or more. In addition, the stirring time in the stirring process is preferably 45 minutes or less, more preferably 30 minutes or less, and even more preferably 10 minutes or less.

[0121] Process D: Filtration process

[0122] The filtration step is performed after the polyvinyl alcohol composition is manufactured. This step removes aggregates from the polyvinyl alcohol composition. According to one embodiment of the invention, the process further includes a filtration step of filtering the polyvinyl alcohol composition obtained through the aforementioned addition step.

[0123] The polyvinyl alcohol (PVA) content in the PVA composition used in the filtration process is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass. Furthermore, the PVA content in the PVA composition is preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less. If the PVA content is within the above range, the viscosity of the PVA composition will not be too high, resulting in a high filtration rate, which is therefore preferable.

[0124] There are no particular limitations on the filter media used in the filtration of polyvinyl alcohol compositions, and examples include polypropylene, polystyrene (PS), polyethersulfone, nylon, nylon 66, cellulose, cellulose mixed esters, cellulose acetate, nitrocellulose, regenerated cellulose, polytetrafluoroethylene (PTFE), polycarbonate, glass, polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer, polyamide, triacetyl cellulose, polyvinyl chloride (PVC), polysulfone, polyester, polypropylene / polyethylene, acrylic copolymers, polylactic acid, polycaprolactone, polyglycolic acid, polydioxanone, polyhydroxybutyrate, polybutadiene, polyurethane, polymethyl methacrylate, and metals.

[0125] There are no particular limitations on filter structures; examples include depth structures, pleated structures, and membrane structures.

[0126] There are no particular limitations on the pore size of the filter, but it is preferably 0.03 μm or more, more preferably 0.04 μm or more, further preferably 0.05 μm or more, even more preferably 0.1 μm or more, and particularly preferably 0.2 μm or more. A high filtration rate is obtained when the filter pore size is 0.03 μm or more, and therefore it is preferred. Furthermore, a pore size of 100 μm or less is preferred, more preferably 70 μm or less, and further preferably 50 μm or less. The pore size of the filter can be 20 μm or less, 10 μm or less, 5 μm or less, or 1 μm or less. A pore size of 100 μm or less improves the filtration accuracy, and therefore it is preferred.

[0127] The filtration method can be any one of the following: natural filtration, vacuum filtration, pressure filtration, or centrifugal filtration performed under normal pressure.

[0128] The filtration process can be performed two or more times. In this case, it is preferable to appropriately change conditions such as the filter pore size. For example, in the first dissolution filtration, a filter with a large pore size can be used to remove coarse particles, and in the second dissolution filtration, a filter with a small pore size can be used to remove fine particles. By performing dissolution filtration two or more times, impurities can be removed more effectively.

[0129] Process E: Alkali Addition Process

[0130] According to one embodiment of the present invention, the method further includes an alkali addition step in which an alkali is added to the polyvinyl alcohol composition obtained by the liquid addition step. This alkali addition step is suitable for use as a grinding composition and / or a wetting agent for semiconductors, as described later. Details of the alkali addition step are described in the section on grinding compositions and / or wetting agents for semiconductors.

[0131] [Polyvinyl alcohol composition]

[0132] According to one embodiment of the present invention, a polyvinyl alcohol composition containing polyvinyl alcohol is provided. The polyvinyl alcohol composition contains at least polyvinyl alcohol and water by comprising a first liquid and a second liquid. The polyvinyl alcohol composition may also contain a solvent other than water, if desired. Additionally, the polyvinyl alcohol composition may contain abrasive particles, if desired.

[0133] The content of polyvinyl alcohol in the polyvinyl alcohol composition relative to the total mass of the polyvinyl alcohol composition is preferably 0.0001% by mass or more, more preferably 0.0005% by mass or more, even more preferably 0.001% by mass or more, and particularly preferably 0.005% by mass or more. For example, the above content can be set to 0.01% by mass or more, 0.1% by mass or more, or 0.4% by mass or more. Furthermore, the content of polyvinyl alcohol relative to the total mass of the polyvinyl alcohol composition is preferably 10% by mass or less, more preferably 7% by mass or less, even more preferably 5% by mass or less, more preferably 3.5% by mass or less, and particularly preferably 3% by mass or less. For example, the above content can be set to 2% by mass or less, 1.5% by mass or less, or 0.9% by mass or less.

[0134] The polyvinyl alcohol composition obtained by the manufacturing method of the present invention exhibits suppressed aggregate formation and excellent filterability. Therefore, the polyvinyl alcohol composition obtained by the manufacturing method of the present invention is suitable for use as a wetting agent for semiconductors and / or a polishing composition.

[0135] The polyvinyl alcohol composition of the present invention may further contain known additives such as surfactants, water-soluble polymers other than polyvinyl alcohol, chelating agents, organic acids, organic acid salts, inorganic acids, inorganic acid salts, pH adjusters, oxidants, metal corrosion inhibitors, preservatives, and fungicides. The additives contained in this polyvinyl alcohol composition may be added to at least one of the first liquid and the second liquid, thereby adding the additives to the polyvinyl alcohol composition. Alternatively, the additives may be added to the polyvinyl alcohol composition via a solution other than the first liquid and the second liquid, or they may be added directly to the polyvinyl alcohol composition.

[0136] Semiconductor wetting agents and polishing compositions

[0137] The polyvinyl alcohol composition obtained by the manufacturing method of the present invention can be used for a variety of applications. For example, it can be used as an adhesive, a pharmaceutical binder, a dispersant, a film, a cosmetic, a fiber raw material, a paste, a coating, an emulsifier, packaging, grinding, and rinsing after grinding. Among these applications, the use of grinding and rinsing after grinding is preferred.

[0138] According to one aspect of the present invention, a semiconductor wetting agent and / or polishing composition is provided, comprising a polyvinyl alcohol composition manufactured by the manufacturing method of the present invention. Specifically, according to one embodiment of the present invention, a method for manufacturing a semiconductor wetting agent and / or polishing composition is provided, which is a method for manufacturing a semiconductor wetting agent and / or polishing composition containing a polyvinyl alcohol composition, wherein the aforementioned polyvinyl alcohol composition is obtained by a liquid addition step as follows: either the aforementioned first liquid or the aforementioned second liquid is added to a liquid containing either a first liquid and water, or a second liquid other than the aforementioned first liquid. The semiconductor wetting agent of this embodiment contains a polyvinyl alcohol composition. The polyvinyl alcohol composition manufactured by the manufacturing method of the present invention is suitable for use as a semiconductor wetting agent, and therefore can be used as a semiconductor wetting agent. Furthermore, the polishing composition of this embodiment contains a polyvinyl alcohol composition. The polyvinyl alcohol composition manufactured by the manufacturing method of the present invention is suitable for use as a polishing composition, and therefore can be used as a polishing composition. As needed, the semiconductor wetting agent and / or polishing composition of this embodiment may contain other additives such as pH adjusters.

[0139] The semiconductor wetting agent of this method can be composed solely of a polyvinyl alcohol composition. That is, according to one embodiment, the polyvinyl alcohol composition manufactured by the manufacturing method of the present invention is a semiconductor wetting agent.

[0140] Furthermore, the semiconductor wetting agent can be obtained by diluting a polyvinyl alcohol composition manufactured by the manufacturing method of the present invention, for example, with water. Therefore, according to one aspect of the present invention, a semiconductor wetting agent is provided, comprising a polyvinyl alcohol composition manufactured by the manufacturing method of the present invention and a third liquid containing water. That is, according to one aspect of the present invention, a method for manufacturing a semiconductor wetting agent is also provided, comprising mixing a polyvinyl alcohol composition manufactured by the manufacturing method of the present invention and a third liquid containing water.

[0141] The third liquid contains water. The third liquid may also contain known additives such as surfactants, water-soluble polymers, thickeners, pH adjusters (preferably alkalis), complexing agents, preservatives, and fungicides, as needed. Here, the third liquid may be water alone or may also contain a solvent. Examples of solvents contained in the third liquid include alcohols such as methanol, ethanol, and ethylene glycol; ketones such as acetone; and mixtures thereof. According to a more preferred embodiment of the invention, the solvent in the third liquid is substantially composed of water. It should be noted that the term "substantially" used above is the same as the term "substantially" used in the solvent of the second liquid described above.

[0142] Here, when manufacturing a semiconductor wetting agent by mixing a polyvinyl alcohol composition and a third liquid, the same method as the method for manufacturing the polyvinyl alcohol composition described above is suitably used. That is, in the case of manufacturing a semiconductor wetting agent by mixing a polyvinyl alcohol composition and a third liquid, as a preferred embodiment, a liquid addition step is included: adding either the polyvinyl alcohol composition or the third liquid into a liquid of either the polyvinyl alcohol composition or the third liquid.

[0143] Furthermore, in semiconductor wetting agents, there are no particular limitations on the mass ratio (polyvinyl alcohol composition: third liquid) of the polyvinyl alcohol composition to the third liquid. For example, it can be set to 10:90 to 90:10, 15:75 to 75:15, or 20:80 to 80:20.

[0144] Furthermore, according to one aspect of the present invention, a polishing composition is provided, comprising a semiconductor wetting agent containing a polyvinyl alcohol composition manufactured by the manufacturing method of the present invention, and abrasive grains. The polishing composition of this aspect comprises a semiconductor wetting agent containing a polyvinyl alcohol composition and abrasive grains. Additionally, if necessary, the polishing composition of this aspect may contain other additives such as pH adjusters.

[0145] In addition, according to one aspect of the present invention, a method for manufacturing a grinding composition is provided, which includes mixing a semiconductor wetting agent containing a polyvinyl alcohol composition manufactured by the method of the present invention and abrasive particles.

[0146] Polyvinyl alcohol (PVA) contains hydroxyl groups (OH groups) in its molecule. Therefore, PVA has the property of readily agglomerating due to intramolecular or intermolecular hydrogen bonding. If a portion of the PVA contained in a polishing composition and / or a semiconductor wetting agent agglomerates and forms lumps, reducing its dispersibility, the performance in reducing surface defects after polishing and rinsing may be diminished. Using the technology disclosed herein, it is possible to achieve polishing compositions and / or semiconductor wetting agents with improved dispersibility that appropriately suppress the formation of PVA lumps.

[0147] The preferred semiconductor wetting agent and / or polishing composition of the present invention will be described below. It should be noted that matters necessary for the implementation of the present invention, other than those specifically discussed in this specification, can be understood by those skilled in the art based on prior art. The present invention can be implemented based on the disclosures in this specification and common technical knowledge in the field.

[0148] (Polyvinyl alcohol composition)

[0149] The semiconductor wetting agents and / or polishing compositions disclosed herein contain polyvinyl alcohol compositions manufactured by the manufacturing method of the present invention.

[0150] The concentration (purity) of polyvinyl alcohol in semiconductor wetting agents and / or polishing compositions is not particularly limited, and can be set to 0.0001% by mass or more, for example. From the viewpoint of haze reduction, a concentration of 0.0005% by mass or more is preferred, more preferably 0.001% by mass or more, for example 0.003% by mass or more, or 0.005% by mass or more. Furthermore, from the viewpoint of its effectiveness on the substrate, the concentration (purity) of polyvinyl alcohol is generally preferably 0.5% by mass or less, or 0.2% by mass or less, or 0.1% by mass or less.

[0151] (Abrasive grains)

[0152] The grinding composition disclosed herein contains abrasive particles. Specifically, the grinding composition contains a polyvinyl alcohol composition and abrasive particles. The abrasive particles mechanically grind the surface of the object being ground. The material and properties of the abrasive particles are not particularly limited and can be appropriately selected according to the intended use and method of application of the grinding composition. Examples of abrasive particles include inorganic particles, organic particles, and organic-inorganic composite particles. Specific examples of inorganic particles include oxide particles such as 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 iron oxide red 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; and carbonates such as calcium carbonate and barium carbonate. Specific examples of organic particles include polymethyl methacrylate (PMMA) particles, poly(meth)acrylic acid particles (here, (meth)acrylic acid refers to both acrylic acid and methacrylic acid in an inclusive sense), and polyacrylonitrile particles. These abrasive grains can be used alone or in combination of two or more. Furthermore, the abrasive grains can be synthetic or commercially available. It should be noted that semiconductor wetting agents do not contain abrasive grains.

[0153] As the aforementioned abrasive grains, inorganic particles are preferred, particularly particles formed from oxides of metals or semi-metals, and especially silicon dioxide particles. For abrasive compositions that can be used in polishing (e.g., fine polishing) of substrates having surfaces formed of silicon, such as silicon wafers, as described later, the use of silicon dioxide particles as abrasive grains is particularly meaningful. The technology disclosed herein can be preferably implemented, for example, in a manner where the aforementioned abrasive grains are substantially composed of silicon dioxide particles. Here, "substantially" means that 95% or more (preferably 98% or more, more preferably 99% or more, and possibly 100% by mass) of the particles constituting the abrasive grains are silicon dioxide particles.

[0154] Specific examples of silica particles include colloidal silica, fumed silica, and precipitated silica. Silica particles can be used alone or in combination of two or more. From the viewpoint of easily obtaining a polished surface with excellent quality after grinding, colloidal silica is particularly preferred. Examples of colloidal silica include, for instance, colloidal silica produced using water glass (Na silicate) as a raw material via ion exchange, and alkoxide-based colloidal silica (colloidal silica produced through the hydrolysis and condensation reaction of alkoxysilanes). Colloidal silica can be used alone or in combination of two or more.

[0155] Furthermore, the abrasive particles can be surface-modified. Specifically, the silica particles can have cationic groups. That is, the silica particles can be cationic modified silica particles or cationic modified colloidal silica. As colloidal silica with cationic groups (cationic modified colloidal silica), colloidal silica with amino groups immobilized on the surface is preferably described. As a method for manufacturing such colloidal silica with cationic groups, a method described in Japanese Patent Application Publication No. 2005-162533, which involves immobilizing amino-containing silane coupling agents such as aminoethyltrimethoxysilane, aminopropyltrimethoxysilane, aminoethyltriethoxysilane, aminopropyltriethoxysilane, aminopropyldimethylethoxysilane, aminopropylmethyldiethoxysilane, and aminobutyltriethoxysilane onto the surface of silica particles, can be obtained. Thus, colloidal silica with amino groups immobilized on the surface (amino-modified colloidal silica) can be obtained.

[0156] Silica particles can possess anionic groups. That is, silica particles can be anionic modified silica particles or anionic modified colloidal silica. As colloidal silica possessing anionic groups (anionic modified colloidal silica), colloidal silica in which anionic groups such as carboxylic acid groups, sulfonic acid groups, phosphonic acid groups, and aluminate groups are immobilized on the surface is preferably described. There are no particular limitations on the method for manufacturing such colloidal silica possessing anionic groups; for example, a method of reacting a silane coupling agent with terminal anionic groups with colloidal silica can be described.

[0157] As a specific example, if sulfonic acid groups are immobilized on colloidal silica, this can be done, for instance, using the method described in "Sulfonicacid-functionalized silica through of thiol groups", Chem. Commun. 246-247 (2003). Specifically, after coupling a silane coupling agent containing thiol groups, such as 3-mercaptopropyltrimethoxysilane, to colloidal silica, the thiol groups are oxidized using hydrogen peroxide, thereby obtaining colloidal silica with sulfonic acid groups immobilized on the surface (sulfonic acid-modified colloidal silica).

[0158] Immobilizing carboxylic acid groups on colloidal silica can be achieved, for example, using the method described in "Novel Silane Coupling Agents Containing a Photolabile 2-Nitrobenzyl Ester for Introduction of a Carboxy Group on the Surface of Silica Gel", Chemistry Letters, 3, 228-229 (2000). Specifically, colloidal silica is coupled with a silane coupling agent containing a photoreactive 2-nitrobenzyl ester and then irradiated with light, thereby obtaining colloidal silica with carboxylic acid groups immobilized on the surface (carboxylic acid-modified colloidal silica).

[0159] The true specific gravity of the abrasive constituent material (e.g., silica constituting silica particles) is preferably 1.5 or more, more preferably 1.6 or more, and even more preferably 1.7 or more. There is no particular upper limit to the true specific gravity of the abrasive constituent material (e.g., silica constituting silica particles), typically 2.3 or less, for example, 2.2 or less. The true specific gravity of the abrasive particles (e.g., silica particles) can be determined using a liquid displacement method obtained by using ethanol as the displacement fluid.

[0160] The BET diameter of the abrasive grains (typically silica particles) is not particularly limited, but from the viewpoint of grinding efficiency, it is preferably 5 nm or more, more preferably 10 nm or more. From the viewpoint of obtaining higher grinding effects (e.g., haze reduction, defect removal, etc.), the aforementioned BET diameter is preferably 15 nm or more, more preferably 20 nm or more (e.g., more than 20 nm). In addition, from the viewpoint of preventing scratches, the BET diameter of the abrasive grains is preferably 100 nm or less, more preferably 50 nm or less, and even more preferably 40 nm or less. The technology disclosed herein is preferably applicable to grinding where a high-quality surface is required after grinding, from the viewpoint of easily obtaining a high-quality surface (e.g., a surface with a low LPD number). As the abrasive grains used in the above-described grinding composition, abrasive grains with a BET diameter of 35 nm or less (typically less than 35 nm, more preferably 32 nm or less, for example less than 30 nm) are preferred.

[0161] It should be noted that in this specification, the BET diameter refers to the specific surface area (BET value) measured using the BET method, and the BET diameter (nm) = 6000 / (true density (g / cm³)). 3 )×BET value (m 2 The particle size can be calculated using the formula ( / g). For example, in the case of silica particles, the particle size can be calculated using the formula: BET diameter (nm) = 2727 / BET value (m). 2 The BET diameter can be calculated using (g). Specific surface area can be measured, for example, using a surface area measuring device manufactured by Micromeritics Instrument Corporation, trade name "Flow Sorb II 2300".

[0162] The average secondary particle size of the abrasive grains is not particularly limited, but from the viewpoint of grinding efficiency, it is preferably 10 nm or more, more preferably 15 nm or more, even more preferably 20 nm or more, and particularly preferably 25 nm or more. From the viewpoint of obtaining higher grinding effects, such as haze reduction and defect removal, the above-mentioned average secondary particle size is preferably 30 nm or more, more preferably 40 nm or more. In addition, from the viewpoint of suppressing the local stress provided by the abrasive grains to the substrate surface, the average secondary particle size of the abrasive grains is preferably 300 nm or less, more preferably 200 nm or less, even more preferably 150 nm or less, and even more preferably 125 nm or less. In the technology disclosed herein, from the viewpoint of easily obtaining a higher quality surface, it is preferable to use abrasive grains with an average secondary particle size of 100 nm or less, for example, less than 80 nm (typically 45 nm or less), because the stability of the grinding composition is improved by reducing the achievable average secondary particle size of the abrasive grains. It should be noted that the average secondary particle size of the abrasive grains can be measured, for example, by using the dynamic light scattering method of the "UPA-UT151" manufactured by Nikkiso Co., Ltd.

[0163] The shape (outer shape) of the abrasive grains can be spherical or non-spherical. Specific examples of non-spherical particles include peanut-shaped (i.e., the shape of a peanut shell), cocoon-shaped, konpeito-shaped, and rugby ball-shaped particles. For example, it is preferable to use abrasive grains that are mostly shaped like peanuts or cocoons.

[0164] While not specifically limited, the average length-to-diameter ratio (LTR) of the abrasive grains is generally 1.0 or higher, preferably 1.05 or higher, and even more preferably 1.1 or higher. Increasing the LRR achieves higher grinding efficiency. Furthermore, from the viewpoint of reducing scratches, the LRR of the abrasive grains is preferably 3.0 or lower, more preferably 2.0 or lower, and even more preferably 1.5 or lower.

[0165] The shape (outline) and average aspect ratio of abrasive grains can be determined, for example, by observation using an electron microscope. The specific steps for determining the average aspect ratio are as follows: using a scanning electron microscope (SEM), for a predetermined number (e.g., 200) of abrasive grains whose individual grain shapes can be identified, draw the smallest rectangle circumscribed to the image of each grain. Then, for each rectangle drawn for the grain image, divide the length of its longer side (the value of the major diameter) by the length of its shorter side (the value of the minor diameter) to calculate the aspect ratio (length / minor diameter). The average aspect ratio can be obtained by arithmetically averaging the aspect ratios of the predetermined number of grains.

[0166] The content of abrasive particles in the grinding composition is not particularly limited, but typically it is 0.01% by mass or more, preferably 0.05% by mass or more, more preferably 0.10% by mass or more, and for example, 0.15% by mass or more. Increasing the abrasive particle content allows for higher grinding speeds. From the viewpoint of the dispersion stability of the abrasive particles in the grinding composition, it is generally suitable for the above content to be 10% by mass or less, preferably 7% by mass or less, more preferably 5% by mass or less, even more preferably 2% by mass or less, for example, 1% by mass or less, and may also be 0.7% by mass or less. In a preferred embodiment, the above content may be 0.5% by mass or less, 0.4% by mass or less, or 0.2% by mass or less.

[0167] (surfactant)

[0168] The grinding compositions and / or semiconductor wetting agents disclosed herein may contain surfactants to a extent that does not significantly impair the effects of the present invention. Any of the anionic, cationic, nonionic, or amphoteric surfactants may be used as surfactants. The grinding compositions and / or semiconductor wetting agents disclosed herein may be implemented in a manner that substantially does not contain surfactants.

[0169] Anionic surfactants are classified, for example, into sulfuric acid-based, sulfonic acid-based, phosphoric acid-based, phosphonic acid-based, and carboxylic acid-based surfactants. Specific examples of anionic surfactants include alkyl sulfates, polyoxyethylene alkyl sulfates, polyoxyethylene alkyl sulfates, alkyl sulfates, alkyl ether sulfates, higher alcohol sulfates, alkyl phosphates, alkylbenzene sulfonic acids, α-olefin sulfonic acids, alkyl sulfonic acids, styrene sulfonic acids, alkylnaphthalene sulfonic acids, alkyl diphenyl ether disulfonic acids, polyoxyethylene alkyl ether acetic acid, polyoxyethylene alkyl ether phosphoric acid, polyoxyethylene alkyl phosphates, polyoxyethylene sulfosuccinic acid, alkyl sulfosuccinic acid, or their salts, taurine-based surfactants, sarcosine-based surfactants, hydroxyethyl sulfonate-based surfactants, N-acyl acidic amino acid-based surfactants, higher fatty acid salts, acylated peptides, etc. Specific examples of alkyl sulfonic acids or their salts include dodecyl sulfonic acid and dodecyl sulfonate, etc.

[0170] Cationic surfactants are classified, for example, as polyoxyethylene alkylamines, alkylalkanolamides, alkylamine salts, amine oxides, quaternary ammonium salts, and tertiary amide amines. Specific examples of cationic surfactants include coconut amine acetate, stearylamine acetate, lauryl dimethylamine oxide, dimethylaminopropyl stearate, alkyl trimethylammonium salt, alkyl dimethylammonium salt, and alkyl benzyl dimethylammonium salt.

[0171] Specific examples of amphoteric surfactants include alkyl betaine series and alkyl amine oxide series. Examples of specific amphoteric surfactants include cocoyl betaine, lauramidopropyl betaine, cocamidopropyl betaine, sodium lauroamphoacetate, sodium cocamidopropyl betaine, coconut oil fatty acid amamidopropyl betaine, and lauryl betaine (lauryl dimethylaminoacetic acid betaine).

[0172] Specific examples of nonionic surfactants include alkylene oxide polymers such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; polyalkylene oxide derivatives (e.g., polyoxyethylene adducts) such as polyoxyethylene alkyl ethers, polyoxyethylene alkylamines, polyoxyethylene alkyl alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene glycerol ether fatty acid esters, and polyoxyethylene sorbitol fatty acid esters; copolymers of various alkylene oxides (e.g., diblock copolymers, triblock copolymers, random copolymers, and alternating copolymers); sucrose fatty acid esters, sorbitol fatty acid esters, glycerol fatty acid esters, polyoxyethylene fatty acid esters, and alkylalkanolamides. These surfactants can be used alone or in combination of two or more.

[0173] The number of carbon atoms in the alkyl group of the polyoxyethylene alkyl ether that can be used herein is not particularly limited. For example, the number of carbon atoms in the alkyl group is preferably 5 or more, more preferably 6 or more, further preferably 7 or more, particularly preferably 8 or more, and specifically 9 or more. For example, the number of carbon atoms in the alkyl group is preferably 12 or less, more preferably 11 or less. The number of carbon atoms in the alkyl group is, for example, 10. In addition, the number of molar additions of ethylene oxide in the polyoxyethylene alkyl ether is not particularly limited, but is preferably 4 or more, more preferably 5 or more, preferably 15 or less, more preferably 10 or less, further preferably 8 or less, and particularly preferably 7 or less. From the viewpoint of reducing surface defects, as a surfactant used in the polishing composition and / or semiconductor wetting agent disclosed herein, a polyoxyethylene octyl ether with a number of molar additions of ethylene oxide of 4 to 10 (e.g., 6) is preferably used.

[0174] Specific examples of nonionic surfactants containing polyoxyalkylene structures include block copolymers of ethylene oxide (EO) and propylene oxide (PO) (diblock copolymers, PEO-PPO-PEO triblock copolymers, PPO-PEO-PPO triblock copolymers, etc.), random copolymers of EO and PO, polyoxyethylene glycol, polyoxyethylene propyl ether, polyoxyethylene butyl ether, polyoxyethylene pentyl ether, polyoxyethylene hexyl ether, polyoxyethylene octyl ether, polyoxyethylene-2-ethylhexyl ether, polyoxyethylene nonyl ether, polyoxyethylene decyl ether, polyoxyethylene isodecanyl ether, polyoxyethylene tridecyl ether, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, and polyoxyethylene isostearyl ether. Ethers, polyoxyethylene oleyl ether, polyoxyethylene phenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene styrene phenyl ether, polyoxyethylene laurylamine, polyoxyethylene stearylamine, polyoxyethylene oleylamine, polyoxyethylene monolaurate, polyoxyethylene monostearate, polyoxyethylene distearate, polyoxyethylene monooleate, polyoxyethylene dioleate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tetraoleate, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, etc.

[0175] The weight-average molecular weight (Mw) of the surfactant is preferably less than 2000, more preferably less than 1500, further preferably less than 700, and particularly preferably less than 500. Furthermore, when the surfactant is a polyoxyalkylene derivative, its Mw is preferably 100 or more, more preferably more than 200, and further preferably more than 300. By using a grinding composition and / or a wetting agent for semiconductors containing a surfactant with an Mw within the above-mentioned range, surface defects are appropriately reduced. The weight-average molecular weight of the surfactant can be calculated from its chemical formula.

[0176] The concentration of the surfactant in the polishing composition and / or the semiconductor wetting agent is not particularly limited, and for example, it can be set to 0.0001% by mass or more, preferably 0.0003% by mass or more. Furthermore, the concentration of the surfactant in the polishing composition and / or the semiconductor wetting agent is generally preferably set to 0.2% by mass or less, more preferably 0.1% by mass or less, and may also be 0.05% by mass or less. In a preferred embodiment, the concentration of the surfactant in the polishing composition and / or the semiconductor wetting agent can be 0.0001% by mass or more and 0.002% by mass or less, or 0.0002% by mass or more and 0.001% by mass or less. In other preferred embodiments, the concentration of the surfactant in the polishing composition and / or the semiconductor wetting agent may also be 0.005% by mass or more and 0.03% by mass or less.

[0177] The molar ratio of polyvinyl alcohol (PVA) content to surfactant content in the grinding composition and / or semiconductor wetting agent is preferably 1 or less, more preferably 0.5 or less, and even more preferably 0.1 or less (e.g., 0.07 or less). Furthermore, the molar ratio of PVA content to surfactant content in the above-described manner is typically 0.01 or more, preferably 0.02 or more, more preferably 0.03 or more, and even more preferably 0.04 or more. When PVA and surfactant are contained in the above-described mixing ratio, the aggregation of PVA is appropriately suppressed, and surface defects are easily reduced.

[0178] (Water-soluble polymers other than polyvinyl alcohol)

[0179] As water-soluble polymers other than polyvinyl alcohol, examples include compounds containing hydroxyl, carboxyl, acyloxy, sulfonyl, amide, imide, quaternary ammonium, heterocyclic, and vinyl structures. Furthermore, as water-soluble polymers other than polyvinyl alcohol, any of the following can be used: natural polymers, semi-synthetic polymers, and synthetic polymers. There are no particular limitations on natural polymers, but polysaccharides are preferred. There are no particular limitations on semi-synthetic polymers, but cellulose derivatives and starch derivatives are preferred. There are no particular limitations on synthetic polymers, but polymers having alkylene oxide units and polymers containing nitrogen atoms are preferred. As a type of polymer containing nitrogen atoms, N-vinyl polymers and N-(meth)acryloyl polymers can be used. Specific examples of these compounds will be described later.

[0180] As polysaccharides, there are no particular restrictions, and examples include carrageenan, xanthan gum, glycogen, alginic acid, pectin, pectic acid, starch, starch derivatives, amylose, amylopectin, agar, gel polysaccharides, pullulan, guar gum, konjac mannan, tamarind gum, etc.

[0181] There are no particular limitations on what constitutes a cellulose derivative, and examples include hydroxyethyl cellulose (hereinafter also referred to as "HEC"), hydroxypropyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, ethyl cellulose, ethyl hydroxyethyl cellulose, carboxymethyl cellulose, and pullulan, among others. Cellulose derivatives can be used alone or in combination of two or more. Here, cellulose derivatives refer to those in which the main repeating unit contains a β-glucose unit, and in which some of the hydroxyl groups present in cellulose are replaced by other substituents.

[0182] There are no particular limitations on what constitutes a starch derivative; examples include cationic starch, phosphate starch, and carboxymethyl starch salts. Here, starch derivatives refer to polymers whose main repeating unit is an α-glucose unit.

[0183] There are no particular limitations on the polymer having alkylene oxide units, and examples include block copolymers of polyethylene oxide (PEO), polypropylene oxide (PPO), ethylene oxide (EO), and propylene oxide (PO) or butene oxide (BO), as well as random copolymers of EO and PO or BO. Among these, block copolymers of EO and PO or random copolymers of EO and PO are preferred. Block copolymers of EO and PO can be diblock copolymers, triblock copolymers, etc., containing PEO blocks and polypropylene oxide (PPO) blocks. Examples of the aforementioned triblock copolymers include PEO-PPO-PEO type triblock copolymers and PPO-PEO-PPO type triblock copolymers. Among these, PEO-PPO-PEO type triblock copolymers are more preferred.

[0184] In block copolymers or random copolymers of EO and PO, the molar ratio of EO to PO constituting the copolymer [EO / PO] is preferably greater than 1, more preferably 2 or more, and even more preferably 3 or more, from the viewpoint of water solubility and detergency. In a further preferred embodiment, the above molar ratio [EO / PO] is, for example, 5 or more.

[0185] Examples of N-vinyl polymers include polymers containing repeating units derived from monomers having nitrogen-containing heterocycles (e.g., lactam rings). Examples of such polymers include homopolymers and copolymers of N-vinyl lactam monomers (e.g., copolymers with a copolymerization ratio of N-vinyl lactam monomers exceeding 50% by mass), homopolymers and copolymers of N-vinyl chain amides (e.g., copolymers with a copolymerization ratio of N-vinyl chain amides exceeding 50% by mass), etc.

[0186] Specific examples of N-vinyllactam type monomers (i.e., compounds having a lactam structure and N-vinyl groups within a single molecule) include N-vinylpyrrolidone (VP), N-vinylpiperidone, N-vinylmorpholinone, N-vinylcaprolactam (VC), N-vinyl-1,3-oxazin-2-one, and N-vinyl-3,5-morpholinedione. Specific examples of polymers containing N-vinyllactam type monomer units include random copolymers of polyvinylpyrrolidone, polyvinylcaprolactam, VP, and VC; random copolymers of one or both of VP and VC with other vinyl monomers (e.g., acrylic monomers, vinyl ester monomers, etc.); block copolymers containing polymer chains containing one or both of VP and VC; alternating copolymers; and graft copolymers.

[0187] Specific examples of N-vinyl chain amides include N-vinylacetamide, N-vinylpropionic acid amide, and N-vinylbutyric acid amide.

[0188] Examples of N-(meth)acryloyl polymers include homopolymers and copolymers of N-(meth)acryloyl monomers (typically copolymers in which the copolymerization ratio of N-(meth)acryloyl monomers exceeds 50% by mass). Examples of N-(meth)acryloyl monomers include chain amides having an N-(meth)acryloyl group and cyclic amides having an N-(meth)acryloyl group.

[0189] Examples of chain amides having an N-(meth)acryloyl group include (meth)acrylamide; N-alkyl (meth)acrylamides such as N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, N-isopropyl(meth)acrylamide, and N-n-butyl(meth)acrylamide; and N,N-dialkyl (meth)acrylamides such as N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-dipropyl(meth)acrylamide, N,N-diisopropyl(meth)acrylamide, and N,N-di(n-butyl)(meth)acrylamide. Examples of polymers containing chain amides having an N-(meth)acryloyl group as monomer units include homopolymers of N-isopropylacrylamide and copolymers of N-isopropylacrylamide (e.g., copolymers in which the copolymerization ratio of N-isopropylacrylamide exceeds 50% by mass).

[0190] Examples of cyclic amides having an N-(meth)acrylyl group include N-acryloylmorpholine, N-acryloylthiomorpholine, N-acryloylpiperidine, N-acryloylpyrrolidine, N-methacryloylmorpholine, N-methacryloylpiperidine, and N-methacryloylpyrrolidine. Examples of polymers containing cyclic amides having an N-(meth)acrylyl group as monomer units include acryloylmorpholine polymers (PACMO). Typical examples of acryloylmorpholine polymers include homopolymers of N-acryloylmorpholine (ACMO) and copolymers of ACMO (e.g., copolymers with a copolymerization ratio of ACMO exceeding 50% by mass). In acryloylmorpholine polymers, it is generally suitable for the molar percentage of ACMO units to the total molar percentage of all repeating units to be 50% or more, or 80% or more (e.g., 90% or more, typically 95% or more). All repeating units of a water-soluble polymer can be substantially composed of ACMO units.

[0191] Other examples of polymers containing nitrogen atoms include imine derivatives such as polyhydroxyethylacrylamide (PHEAA), poly-N-vinylimidazolium (PVI), poly-N-vinylcarbazole, and poly-N-vinylpiperidine. Polymers containing nitrogen atoms can be homopolymers or copolymers, and can be used alone or in combination of two or more.

[0192] Furthermore, water-soluble polymers other than polyvinyl alcohol can be water-soluble polymers having at least one functional group selected from cationic, anionic, and nonionic groups in their molecules. From the viewpoints of reducing aggregates and improving washability, nonionic polymers are preferred as the aforementioned water-soluble polymers.

[0193] In addition, specific examples of other water-soluble polymers include polycarboxylic acids, polycarboxamides, polycarboxylic esters, polyphosphonic acids, polystyrene sulfonic acids, polysulfone acids, ethylene oxide polymers, vinyl polymers, cationic polymers, and their copolymers, salts, and derivatives. Specific examples of polycarboxylic acids, polycarboxamides, polycarboxylic esters, or polycarboxylates include polyaspartic acid, polyglutamic acid, polylysine, polymalic acid, polymethacrylic acid, polyammonium methacrylate, sodium methacrylate, polymaleic acid, polyitacrylic acid, polyfumaric acid, poly(p-styrenecarboxylic acid), polyacrylic acid, polyacrylamide, aminopolyacrylamide, polymethyl acrylate, polyethyl acrylate, polyammonium methacrylate, sodium methacrylate, polyamic acid, polyamic acid ammonium salt, sodium polyamic acid, polyglyoxylic acid hydrate, etc. Specific examples of cationic polymers include cationic cellulose derivatives, cationic starch, cationic guar gum derivatives, diallyl quaternary ammonium salt / acrylamide copolymers, quaternized polyvinylpyrrolidone derivatives, and dicyandiamide-diethylenetriamine condensates. These water-soluble polymers can be used alone or in combination of two or more.

[0194] The weight-average molecular weight (Mw) of water-soluble polymers is typically 2 × 10⁻⁶. 3 The above, or 5×10 3 The above, or 1×10 4 The above, or 5×10 4 The above, or 10×10 4 The above, or 20×10 4 That's all. Additionally, the Mw of the dispersant can be 100 × 10⁻⁶. 4 The following can also be 50×10 4 The following can also be 45×10 4 The following can also be 40×10 4 the following.

[0195] The concentration of the water-soluble polymer in the polishing composition and / or semiconductor wetting agent is not particularly limited, and can be, for example, 0.0001% by mass or more, preferably 0.0003% by mass or more. Furthermore, the concentration of the water-soluble polymer in the polishing composition and / or semiconductor wetting agent is generally preferably 0.2% by mass or less, more preferably 0.1% by mass or less, and may also be 0.05% by mass or less. In a preferred embodiment, the concentration of the water-soluble polymer in the polishing composition and / or semiconductor wetting agent may be 0.0001% by mass or more and 0.002% by mass or less, or 0.0002% by mass or more and 0.001% by mass or less. In another preferred embodiment, the concentration of the water-soluble polymer in the polishing composition and / or semiconductor wetting agent may be 0.005% by mass or more and 0.03% by mass or less.

[0196] The molar ratio of polyvinyl alcohol (PVA) content to water-soluble polymer content in the grinding composition and / or semiconductor wetting agent is preferably 15 or less, more preferably 10 or less, and even more preferably 5 or less (e.g., 4 or less). Furthermore, the molar ratio of PVA content to water-soluble polymer content in the above-described manner is typically 0.1 or more, preferably 0.3 or more, more preferably 0.5 or more, and even more preferably 1 or more. When PVA and water-soluble polymer are contained in the above-described mixing ratio, the aggregation of PVA is appropriately suppressed, and surface defects are easily reduced.

[0197] (pH adjuster)

[0198] The grinding compositions and / or semiconductor wetting agents disclosed herein may also contain a pH adjuster. The pH adjuster is added primarily to adjust the pH of the grinding compositions and / or semiconductor wetting agents disclosed herein. There are no particular limitations on the pH adjuster being a compound with pH-adjusting function; known compounds can be used. Examples include bases and acids.

[0199] In this specification, a base refers to a compound that dissolves in water and raises the pH of the aqueous solution. Bases can be nitrogen-containing organic or inorganic bases, alkali metal hydroxides, alkaline earth metal hydroxides, various carbonates, bicarbonates, etc. Examples of nitrogen-containing bases include quaternary ammonium compounds, quaternary phosphorus compounds, ammonia, and amines (preferably water-soluble amines).

[0200] Specific examples of alkali metal hydroxides include potassium hydroxide and sodium hydroxide. Specific examples of carbonates or bicarbonates include ammonium bicarbonate, ammonium carbonate, potassium bicarbonate, potassium carbonate, sodium bicarbonate, and sodium carbonate. Specific examples of amines include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, monoethanolamine, N-(β-aminoethyl)ethanolamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, anhydrous piperazine, piperazine hexahydrate, 1-(2-aminoethyl)piperazine, N-methylpiperazine, guanidine, imidazole, triazole, and other azoles. Specific examples of quaternary phosphorus compounds include tetramethylphosphonium hydroxide and tetraethylphosphonium hydroxide.

[0201] As quaternary ammonium compounds, tetraalkylammonium salts, hydroxyalkyltrialkylammonium salts, and other quaternary ammonium salts (typically strong bases) are preferred. The anionic component of these quaternary ammonium salts can, for example, be OH-. - F - Cl - ,Br - I - ,ClO 4- BH 4- Etc. Among these, as a preferred example, anion such as OH- can be listed. - Quaternary ammonium salts, namely quaternary ammonium hydroxides. Specific examples of quaternary ammonium hydroxides include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrapentylammonium hydroxide, and tetrahexylammonium hydroxide, etc.; hydroxyalkyltrialkylammonium hydroxides such as 2-hydroxyethyltrimethylammonium hydroxide (also known as choline); etc.

[0202] Among these bases, at least one base selected from alkali metal hydroxides, quaternary ammonium hydroxides, and ammonia can be preferably used. More preferably, tetraalkylammonium hydroxide (e.g., tetramethylammonium hydroxide) and ammonia, with ammonia being particularly preferred.

[0203] According to one embodiment of the present invention, an alkali addition step is further included, in which an alkali is added to the polyvinyl alcohol composition obtained through the liquid addition step. By performing the alkali addition step on the polyvinyl alcohol composition of the present invention, an alkaline polyvinyl alcohol composition is formed, which can preferably be used as a grinding composition and / or a wetting agent for semiconductors. The alkali addition step is preferably performed by mixing the polyvinyl alcohol composition obtained through the liquid addition step with a third liquid containing alkali.

[0204] In this specification, "acid" refers to a compound that has the function of dissolving in water and lowering the pH of an aqueous solution. Any of the inorganic or organic acids can be used as the acid. There are no particular limitations on inorganic acids, and examples include sulfuric acid, nitric acid, boric acid, carbonic acid, hypophosphorous acid, phosphorous acid, and phosphoric acid. There are no particular limitations on organic acids, and examples include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, hexanoic acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid, 4-methylvaleric acid, heptanoic acid, 2-methylhexanoic acid, octanoic acid, 2-ethylhexanoic acid, benzoic acid, glycolic acid, salicylic acid, glyceric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, malic acid, tartaric acid, citric acid, and lactic acid, as well as methanesulfonic acid, ethanesulfonic acid, and hydroxyethylsulfonic acid. Among these, maleic acid or nitric acid is more preferred, and maleic acid is even more preferred.

[0205] There is no particular limitation on the content of the pH adjuster. It can be appropriately selected so that the pH of the polyvinyl alcohol composition of one aspect of the present invention, the semiconductor wetting agent of one aspect of the present invention, and the grinding composition of one aspect of the present invention is within the desired range.

[0206] When the polishing composition and / or semiconductor wetting agent disclosed herein contain an alkali, the concentration of the alkali in the polishing slurry is not particularly limited. From the viewpoint of its effectiveness on the substrate surface, the concentration is generally set to 0.001% by mass or more, more preferably 0.003% by mass or more (e.g., 0.005% by mass or more) of the polishing slurry. Furthermore, from the viewpoint of haze reduction, a concentration less than 0.3% by mass is suitable, preferably less than 0.1% by mass, more preferably less than 0.05% by mass, and particularly preferably less than 0.03% by mass (e.g., less than 0.025% by mass, and further less than 0.01% by mass).

[0207] (chelating agent)

[0208] The grinding compositions and / or semiconductor wetting agents disclosed herein may further contain chelating agents. Chelating agents may be used alone or in combination of two or more. Examples of the aforementioned chelating agents include aminocarboxylic acid chelating agents and organophosphonic acid chelating agents. Preferred examples of chelating agents include, for example, ethylenediaminetetra(methylenephosphonic acid), diethylenetriaminepenta(methylenephosphonic acid), and diethylenetriaminepentaacetic acid. Examples of the aforementioned preservatives and fungicides include isothiazolinone compounds, parabens, phenoxyethanol, etc.

[0209] (Organic acids, organic acid salts, inorganic acids, inorganic acid salts)

[0210] The grinding compositions and / or semiconductor wetting agents disclosed herein may further contain organic acids and their salts, as well as inorganic acids and their salts. Organic acids and their salts, and inorganic acids and their salts, may be used alone or in combination of two or more. 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; itaconic acid, citric acid, oxalic acid, tartaric acid, malic acid, maleic acid, fumaric acid, succinic acid, glycolic acid, malonic acid, gluconic acid, alanine, glycine, lactic acid, organic sulfonic acids such as hydroxyethylidene diphosphate (HEDP) and methanesulfonic acid; organic phosphonic acids such as nitric acid tris(methylene phosphate) (NTMP) and phosphonobutane tricarboxylic acid (PBTC). Examples of organic acid salts include alkali metal salts (sodium salts, potassium salts, etc.) and ammonium salts of organic acids. Examples of inorganic acids include hydrochloric acid, phosphoric acid, sulfuric acid, phosphonic acid, nitric acid, hypophosphonic acid, boric acid, and carbonic acid. Examples of inorganic acid salts include alkali metal salts (sodium salts, potassium salts, etc.) and ammonium salts of inorganic acids.

[0211] (Metal corrosion inhibitor)

[0212] The grinding compositions and / or semiconductor wetting agents disclosed herein may also contain metal corrosion inhibitors. Specific examples of metal corrosion inhibitors include, for instance, pyrrole compounds, pyrazole compounds, imidazole compounds, triazole compounds, tetraazole compounds, pyridine compounds, pyrazine compounds, pyridazine compounds, 4-azaindene compounds, meso-azaindene compounds, indole compounds, isoindole compounds, indazole compounds, purine compounds, quinazine compounds, quinoline compounds, isoquinoline compounds, diazanine compounds, phthalazine compounds, quinoxaline compounds, quinazoline compounds, cyclophosphine compounds, pteridine compounds, thiazole compounds, isothiazole compounds, oxazole compounds, isoxazole compounds, furazine compounds, and other nitrogen-containing heterocyclic compounds. These metal corrosion inhibitors may be used alone or in combination of two or more.

[0213] (Oxidizing agent)

[0214] The grinding compositions and / or semiconductor wetting agents disclosed herein may also contain oxidizing agents. Specific examples of oxidizing agents include peroxides, periodic acid, periodate, permanganate, vanadate, hypochlorite, iron oxide, ozone, etc. Specific examples of peroxides include hydrogen peroxide, peracetic acid, percarbonate, urea peroxide, perchloric acid, perchlorate, and persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate. These oxidizing agents may be used alone or in combination of two or more.

[0215] When using the polishing composition and / or semiconductor wetting agent disclosed herein on a substrate having a surface formed of silicon single crystal, it is preferable that the composition does not substantially contain the aforementioned oxidant. This is because if the oxidant is present, the surface of the silicon substrate will be oxidized to form an oxide film, thereby potentially reducing its effectiveness on the substrate surface. Here, "substantially not containing oxidant" means that at least no oxidant is intentionally mixed in; the presence of trace amounts of oxidant due to raw materials, manufacturing methods, etc., is permissible. The aforementioned trace amounts refer to a molar concentration of the oxidant of 0.0005 mol / L or less (preferably 0.0001 mol / L or less, more preferably 0.00001 mol / L or less, particularly preferably 0.000001 mol / L or less). Preferably, the polishing composition and / or semiconductor wetting agent of one embodiment does not contain the aforementioned oxidant.

[0216] (Preservatives, fungicides)

[0217] The grinding compositions and / or semiconductor wetting agents disclosed herein may also contain preservatives and fungicides. Specific examples of preservatives and fungicides include isothiazolin-based preservatives such as 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one, parabens, phenoxyethanol, etc. These preservatives and fungicides may be used alone or in combination of two or more.

[0218] (pH)

[0219] The pH of the polishing composition and / or semiconductor wetting agent disclosed herein is not particularly limited. The pH is preferably 1.0 or higher, more preferably 2.0 or higher, typically 8.0 or higher, preferably 8.5 or higher, more preferably 9.0 or higher, even more preferably 9.3 or higher, and for example 9.5 or higher. On the other hand, a pH of 12.0 or lower is suitable, preferably 11.0 or lower, more preferably 10.8 or lower, and even more preferably 10.5 or lower.

[0220] For pH, a pH meter (e.g., a glass electrode hydrogen ion concentration indicator (model F-23) manufactured by Horiba Corporation) is used. After calibrating 3 points using standard buffer solutions (phthalate pH buffer pH: 4.01 (25°C), neutral phosphate pH buffer pH: 6.86 (25°C), and carbonate pH buffer pH: 10.01 (25°C)), the glass electrode is added to the composition of the test subject, and the value is measured after more than 2 minutes of stabilization. This allows the pH to be determined.

[0221] [Grinding fluid and rinsing fluid]

[0222] The polishing composition disclosed herein is typically supplied to a substrate in the form of a polishing slurry containing the polishing composition for polishing the substrate. Additionally, the semiconductor wetting agent disclosed herein is typically supplied to a substrate in the form of a rinsing solution containing the semiconductor wetting agent for rinsing the substrate. The polishing slurry can be prepared, for example, by diluting any of the polishing compositions disclosed herein (typically by diluting with water). Alternatively, the polishing composition can be used directly as a polishing slurry. That is, the concept of the polishing composition in the disclosed technology includes both a polishing slurry (working slurry) supplied to a substrate for polishing the substrate, and a concentrated solution (i.e., the stock solution of the polishing slurry) diluted for use as a polishing slurry. The rinsing solution can be prepared, for example, by diluting any of the semiconductor wetting agents disclosed herein (typically by diluting with water). Alternatively, the semiconductor wetting agent can be used directly as a rinsing solution. That is, the concept of a semiconductor wetting agent in the disclosed technology includes both a rinsing solution supplied to a substrate for rinsing the substrate and a concentrated solution diluted for use as a rinsing solution (i.e., the stock solution of the rinsing solution). As another example of a polishing slurry containing the polishing composition disclosed herein, a polishing slurry prepared by adjusting the pH of the composition can be cited. Additionally, as another example of a rinsing slurry containing the semiconductor wetting agent disclosed herein, a rinsing slurry prepared by adjusting the pH of the composition can be cited.

[0223] (Concentrated solution)

[0224] The polishing composition and / or semiconductor wetting agent disclosed herein can be in a concentrated form before being supplied to a substrate. That is, the polishing composition and / or semiconductor wetting agent can be in the form of a concentrated polishing slurry and / or rinsing liquid, or it can be prepared as a concentrate of the polishing slurry and / or rinsing liquid. Such a concentrated form of the polishing composition and / or semiconductor wetting agent is advantageous from the viewpoints of ease of manufacturing, distribution, storage, and cost reduction. The concentration ratio of the concentrate is not particularly limited; for example, it can be set to approximately 2 to 100 times by volume, typically approximately 5 to 50 times (e.g., approximately 10 to 40 times).

[0225] This concentrate can be diluted at a desired time to prepare a polishing slurry (working paste), and then supplied to a substrate. This dilution can be achieved, for example, by adding water to the concentrate and mixing.

[0226] The content of abrasive particles in the above-mentioned concentrate can be set to, for example, 50% by mass or less. From the viewpoint of the processability of the above-mentioned concentrate (e.g., the dispersion stability and filterability of the abrasive particles), the content of abrasive particles in the above-mentioned concentrate is generally preferably 45% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, and even more preferably 20% by mass or less (e.g., 10% by mass or less). Furthermore, from the viewpoint of convenience in manufacturing, distribution, and storage, and cost reduction, the content of abrasive particles can be set to, for example, 0.5% by mass or more, preferably 1% by mass or more, more preferably 2% by mass or more, and for example, 3% by mass or more. In one preferred embodiment, the content of abrasive particles can be set to 4% by mass or more, or 5% by mass or more.

[0227] [Preparation of grinding compositions and semiconductor wetting agents]

[0228] The polishing composition used in the disclosed technology can be a single-component type or a multi-component type, represented by a two-component type. For example, it can be configured by mixing a portion A containing at least abrasive particles and a portion B containing at least a portion of the remaining components, and mixing and diluting them as needed at appropriate times to produce a polishing slurry. The semiconductor wetting agent used in the disclosed technology can be a single-component type or a multi-component type, represented by a two-component type. For example, it can be configured by mixing a portion A containing at least polyvinyl alcohol and a portion B containing at least a portion of the remaining components and mixing and diluting them as needed at appropriate times to produce a rinsing solution.

[0229] The preparation method of the grinding composition and / or semiconductor wetting agent is not particularly limited. For example, well-known mixing devices such as blade mixers, ultrasonic dispersers, and homogeneous mixers can be used to mix the components constituting the grinding composition and / or semiconductor wetting agent. The manner in which these components are mixed is not particularly limited; for example, all components can be mixed at once or in a suitably predetermined order. In one embodiment, the method of manufacturing the grinding composition includes mixing a semiconductor wetting agent and abrasive grains.

[0230] [Substrate]

[0231] The polishing composition and / or semiconductor wetting agent of one embodiment of the present invention are applicable to polishing and / or rinsing substrates of various materials and shapes. The substrate material can be, for example, metals or semi-metals such as silicon, aluminum, nickel, tungsten, copper, tantalum, titanium, hafnium, cobalt, and stainless steel, or alloys thereof; glassy materials such as quartz glass, aluminosilicate glass, and glassy carbon; ceramic materials such as alumina, silicon dioxide, sapphire, silicon nitride, tantalum nitride, and titanium carbide; compound semiconductor substrate materials such as silicon carbide, gallium nitride, and gallium arsenide; resin materials such as polyimide resin; etc. A substrate composed of multiple of these materials can also be used. Additionally, it can be a metal, a substrate having oxygen and silicon atoms, a substrate having silicon-silicon bonds, a substrate having nitrogen and silicon atoms, etc. Examples of substrates having oxygen and silicon atoms include silicon oxide (SiO2) and tetraethyl orthosilicate (TEOS) condensate. Examples of substrates with silicon-silicon bonds include polycrystalline silicon, amorphous silicon, monocrystalline silicon, n-type doped monocrystalline silicon, p-type doped monocrystalline silicon, and Si-based alloys such as SiGe. Examples of substrates with both nitrogen and silicon atoms include silicon nitride films and SiCN (silicon carbonitride) films, which have silicon-nitrogen bonds.

[0232] The polishing composition and / or semiconductor wetting agent of one embodiment of the present invention are particularly preferred for polishing and / or rinsing surfaces formed of silicon, typically for polishing and / or rinsing silicon wafers. A typical example of a silicon wafer referred to herein is a single-crystal silicon wafer, such as a single-crystal silicon wafer obtained by slicing a single-crystal silicon ingot.

[0233] The polishing composition and / or semiconductor wetting agent disclosed herein are preferably suitable for polishing processes of substrates (e.g., silicon wafers) and subsequent rinsing processes. The substrate can also be subjected to routine processing upstream of the polishing process, such as lapping or etching, prior to the polishing process using the polishing composition and / or semiconductor wetting agent disclosed herein.

[0234] The polishing compositions and / or semiconductor wetting agents disclosed herein are preferably used, for example, in the polishing and subsequent rinsing of substrates (e.g., silicon wafers) prepared in upstream processes to achieve a surface roughness of 0.1 nm to 100 nm. The surface roughness Ra of the substrate can be measured, for example, using a laser scanning surface roughness meter “TMS-3000WRC” manufactured by Schmitt Measurement Systems Inc. Use in final polishing (fine grinding) or polishing immediately preceding final polishing and in subsequent rinsing is effective, and particularly preferred in final polishing and subsequent rinsing. Here, final polishing refers to the final polishing step in the manufacturing process of the object (i.e., a step after which no further polishing is performed).

[0235] <Grinding and Rinsing>

[0236] The polishing composition disclosed herein can be used for polishing substrates, for example, by including the following operations. Additionally, the semiconductor wetting agent disclosed herein can be used for rinsing substrates, for example, by including the following operations. Preferred methods for polishing substrates (e.g., silicon wafers) using the polishing composition disclosed herein and for rinsing substrates (e.g., silicon wafers) using the semiconductor wetting agent disclosed herein will be described below.

[0237] That is, a grinding slurry containing any of the grinding compositions disclosed herein is prepared. Preparing the grinding slurry can include operations such as adjusting the concentration (e.g., dilution) and pH of the grinding composition. Alternatively, the grinding composition can be used directly as the grinding slurry.

[0238] Next, the polishing slurry is supplied to the substrate, and polishing is performed using conventional methods. For example, in the case of fine polishing of a silicon wafer, typically, a silicon wafer that has undergone a lapping process is mounted in a conventional polishing apparatus, and polishing slurry is supplied to the polishing target surface of the silicon wafer through the polishing pad of the polishing apparatus. Typically, while the polishing slurry is continuously supplied, the polishing pad is pressed against the polishing target surface of the silicon wafer, and the two are moved relative to each other (e.g., rotated). The polishing of the substrate is completed through the above polishing process.

[0239] Next, a rinsing solution containing any of the semiconductor wetting agents disclosed herein is prepared. Preparing the rinsing solution can include adjusting the concentration (e.g., dilution), pH, etc., of the semiconductor wetting agent. Alternatively, the semiconductor wetting agent can be used directly as the rinsing solution.

[0240] Next, the rinsing solution is supplied to the substrate, and the polishing pad is pressed against the polished surface of the silicon wafer using the same method as the polishing described above, and the two are moved relative to each other (e.g., rotated). The rinsing of the substrate is completed through the above process.

[0241] (Abrasive pad)

[0242] The abrasive pads used in the above-mentioned abrasive and / or rinsing processes are not particularly limited. For example, abrasive pads of polyurethane foam, non-woven fabric, suede, etc., can be used. Each abrasive pad may or may not contain abrasive particles. Generally, abrasive pads without abrasive particles are preferred.

[0243] [washing]

[0244] The substrate that has been polished and / or rinsed using the polishing composition and / or semiconductor wetting agent according to one embodiment of the present invention is typically washed. Washing can be performed using a suitable washing solution. The washing solution used is not particularly limited; for example, commonly used SC-1 washing solutions, SC-2 washing solutions, etc., in the semiconductor field can be used. Examples of SC-1 washing solutions include a mixture of ammonium hydroxide (NH4OH), hydrogen peroxide (H2O2), and water (H2O). Examples of SC-2 washing solutions include a mixture of HCl, H2O2, and H2O. The temperature of the washing solution can be set, for example, to a range above room temperature up to approximately 90°C. Room temperature is typically approximately 15°C to 25°C. From the viewpoint of improving the washing effect, a washing solution with a temperature of approximately 40°C to 85°C is preferable.

[0245] Example

[0246] The following examples illustrate the present invention in detail, but the invention is not limited thereto. It should be noted that the term "parts" is used in the examples, and unless otherwise specified, it refers to "parts by weight". Furthermore, the PVA mentioned below refers to a saponified form of polyvinyl acetate.

[0247] (Preparation of solution (1))

[0248] Add 1200 parts of room temperature (25°C) water to a 3L container, then add 600 parts of polyvinyl alcohol (PVA-124, manufactured by Kuraray Co., Ltd., degree of polymerization 2400, degree of saponification 98.0–99.0 mol%) (solid content concentration 3.3% by mass). Next, use a mechanical stirrer with propeller blades (manufactured by Shinto Science Co., Ltd., product name: 3-in-1 motor, model BLh1200) at a rotation speed of 250 rpm, and heat until the solution in the container exceeds 90°C to disperse / swell the polyvinyl alcohol. Then, while continuously stirring, heat to 95°C and maintain this temperature while stirring for 1 hour to dissolve the polyvinyl alcohol, obtaining a polyvinyl alcohol aqueous solution.

[0249] Then, the container containing the polyvinyl alcohol aqueous solution was immersed in a water bath for cooling. The polyvinyl alcohol aqueous solution was continuously stirred while being cooled in the water bath, and cooling was stopped when the temperature of the polyvinyl alcohol aqueous solution reached 25°C. It took approximately 30 minutes to go from 95°C to 25°C. Therefore, the cooling rate at this point was calculated to be approximately 2°C / minute. The resulting polyvinyl alcohol aqueous solution was taken as solution (1).

[0250] [Add Experiment]

[0251] In order to conduct the experiment of adding solution (1), preparations were made Figure 1 The device 10 shown. Figure 1The apparatus 10 used in the experiment is shown schematically to illustrate the addition of liquid to the liquid.

[0252] like Figure 1 As shown, solutions (1) are prepared in beakers 11 and 12 as 21a and 21b (e.g., 900 parts each). The suction side of pump 13 is connected to one end of tube 15a, and the discharge side is connected to one end of tube 15b. The other end of tube 15a is immersed in the solutions (1) (21b) in beaker 12, and the other end of tube 15b is immersed in the solutions (1) (21a) in beaker 11. Thus, by operating pump 13, the solutions (1) (21b) in beaker 12 are directly added (added in liquid) to the solutions (1) (21a) in beaker 11 via tubes 15a and 15b. In this experiment, both the first liquid and the second liquid are solutions (1).

[0253] (Example 1)

[0254] The solution (1) obtained above was used Figure 1 The apparatus 10 shown was used to conduct an experiment on adding liquid. 900 portions of solution (1) were prepared in beakers 11 and 12, respectively, as 21a and 21b. It should be noted that the diameters of tubes 15a and 15b are 5 mm, and the inner diameter of beaker 11 (stirring container) is 20 cm. The acceleration of solution (1) (21b) from beaker 12 to solution (1) (21a) from beaker 11 was set to 150-160 mL / min, and the liquid was added to solution (1) over 5 minutes. No stirring was performed during the addition. After the addition was complete, beaker 11 was stirred (at 100 rpm) by a three-in-one motor (device) (not shown). The temperature of the solution (1) added was 25°C, and stirring was performed without heating. The ratio (L / D) of the stirring blade diameter (L) to the inner diameter (D) of the stirring container was 0.5. After stirring, the solution (1)(21a) in beaker 11 is recovered as the polyvinyl alcohol composition (hereinafter, PVA composition) (1) of Example 1.

[0255] (Comparative Example 1)

[0256] In Comparative Example 1, the addition was made by dropwise addition. At this time, in Figure 1In the apparatus 10 shown, the other end of tube 15b is removed from the solution (1) (21a) in beaker 11 and placed 50-60 cm away from the liquid surface of solution (1) (21a) (for example, by holding tube 15b with a clamp), thereby conducting the addition experiment by drop addition. It should be noted that 900 portions of solution (1) are prepared in beakers 11 and 12 respectively as 21a and 21b. The addition rate of solution (1) (21b) from beaker 12 to solution (1) (21a) in beaker 11 is set to 150-160 mL / min, and the solution (1) is added dropwise for 5 minutes. No stirring is performed during drop addition. After the drop addition is completed, beaker 11 is stirred by a three-in-one motor (device) (speed of 100 rpm). The temperature of the solution (1) added dropwise is 25°C, and stirring is performed without heating. After stirring, the solutions (1)(21a) in beaker 11 and (1)(21b) in beaker 12 were combined and recovered as the PVA composition (2) of Comparative Example 1.

[0257] (Refer to Example 1)

[0258] Solution (1) without addition experiments (after being left to stand for 10 minutes after manufacturing) was used as PVA composition (3).

[0259] [Filtering Evaluation]

[0260] The filterability of the solutions used in the additive experiments was evaluated. During the filterability evaluation, DIW correction was performed to eliminate individual differences between filters. Here, DIW correction refers to correcting the difference in filtration capacity between filters using a coefficient calculated based on the filtration performance (filtration time and flow rate) using deionized water.

[0261] • Comparison

[0262] First, each filter was subjected to filtration of 600g of deionized water at 25°C. The filters were made of polypropylene with a pore size of 0.2μm. Filtration was performed by suction filtration. It should be noted that the filtration suction pressure was 0.0125MPa. The filtration weight (g) was measured after a flow time of 100 seconds and 600 seconds. These filtration weights (g) using deionized water were used for DIW calibration of each filter.

[0263] PVA composition

[0264] For each PVA composition obtained above, 600g (25°C) was filtered using the filter used in the control group above, by suction filtration (suction pressure 0.0125MPa). The flow rate was measured at 60-second intervals. Table 1 shows the flow rate (g) of each PVA composition. It should be noted that the values ​​were corrected for DIW.

[0265] • Filter weight DIW calibration

[0266] (Calculation of DIW correction values ​​for each evaluation sample)

[0267] The average value of the filtration weight after 100 seconds of flow time in the filtration of deionized water and the average value of 1 / 6 of the filtration weight after 600 seconds of flow time are added together and used as the "filtration weight after 100 seconds of flow time (average value)". Specifically, for each filter used in the filterability evaluation of each evaluation sample (solutions added in liquid, added dropwise, and solutions left to stand), the average filtration weight after 100 seconds of flow time in the filtration of deionized water is calculated, and the average filtration weight after 100 seconds of flow time in the filtration of deionized water and the average value of 1 / 6 of the filtration weight after 600 seconds of flow time in the evaluation sample using the filter are added together to obtain the "filtration weight after 100 seconds of flow time (average value)". This becomes the "filtration weight after 100 seconds of flow time (average value) of each evaluation sample" in the following formula (1).

[0268] In addition, the average filtration weight of all evaluation samples after a 100-second flushing time was calculated. That is, "the average filtration weight of all evaluation samples after a 100-second flushing time" refers to the average filtration weight of deionized water in filters that underwent in-liquid addition, dropwise addition, and standing solution evaluations (the average of all evaluation samples).

[0269] Using the "filtration weight (average value) of each evaluation sample after 100 seconds of liquid flow" and "average filtration weight of all evaluation samples after 100 seconds of liquid flow" obtained above, calculate the "DIW correction value of each evaluation sample" in the following formula (1) for each evaluation sample.

[0270] (Calculated based on DIW correction of filter weight)

[0271] Based on the correction of the weight of deionized water relative to the flow time in each evaluation sample, the "DIW correction value for each evaluation sample" was used as described below. The filtration quality (filtration quality DIW correction) for each flow time (specified value) of each evaluation sample is shown in Table 1.

[0272] [Equation (1)]

[0273]

[0274] [Equation (2)]

[0275]

[0276] [Table 1]

[0277] Table 1. Filterability evaluation of PVA compositions

[0278]

[0279] As shown in Table 1, the PVA composition (1) with liquid addition exhibits significantly better filterability compared to the PVA composition (2) with dropwise addition, indicating that the filterability is improved through liquid addition. Furthermore, the filterability of the PVA composition (1) with liquid addition is approximately the same as that of the PVA composition (3) that has been left to stand without liquid addition. Therefore, it can be concluded that the formation of aggregates due to addition is significantly suppressed when liquid addition is performed.

[0280] It can be seen that polishing compositions containing PVA composition (1) and / or semiconductor wetting agents are used for polishing and / or rinsing substrates such as silicon wafers, reducing surface defects (e.g., LPD: Light Point Defects) and significantly improving the surface quality of the substrate.

[0281] This application is based on Japanese Patent Application No. 2020-164901, filed on September 30, 2020, the disclosure of which is incorporated herein by reference in its entirety.

[0282] Explanation of reference numerals in the attached figures

[0283] 10 Experimental apparatus for adding liquids

[0284] 11 and 12 beakers

[0285] 13 pumps

[0286] 15a and 15b pipes

[0287] 21a and 21b solutions (1).

Claims

1. A method for manufacturing a semiconductor wetting agent, comprising a method for manufacturing a semiconductor wetting agent containing a polyvinyl alcohol composition. The semiconductor wetting agent does not contain abrasive particles. The manufacturing method includes: In the liquid addition step, to obtain the polyvinyl alcohol composition, a supply pipe is used to add either the first liquid or the second liquid to a liquid containing either polyvinyl alcohol and water, or the second liquid other than the first liquid. The inner diameter of the supply pipe is 5mm or more and 50cm or less. The supply rate of the liquid added using the supply tube is 50 mL / min or more and 20 L / min or less.

2. The method for manufacturing a semiconductor wetting agent according to claim 1, further comprising a filtration step of filtering the polyvinyl alcohol composition obtained through the liquid addition step.

3. The method for manufacturing a semiconductor wetting agent according to claim 1 or 2, wherein, The first liquid is obtained by heating a polyvinyl alcohol dispersion made by dispersing polyvinyl alcohol in water to 85~98°C and then cooling it to 15~50°C.

4. The method for manufacturing a semiconductor wetting agent according to claim 1 or 2, wherein, The liquid addition process is as follows: the first liquid is added to the second liquid which is held in a container with a stirring unit.

5. The method for manufacturing a semiconductor wetting agent according to claim 1 or 2, wherein, In the liquid addition process, the content of polyvinyl alcohol in the polyvinyl alcohol composition is less than 10% by mass relative to the total mass of the polyvinyl alcohol composition.

6. The method for manufacturing a semiconductor wetting agent according to claim 1 or 2, further comprising an alkali addition step of adding an alkali to the polyvinyl alcohol composition obtained by the liquid addition step.

7. A polishing composition comprising a semiconductor wetting agent and abrasive grains manufactured by the manufacturing method according to any one of claims 1 to 6.

8. A method for manufacturing a polishing composition, comprising mixing a semiconductor wetting agent manufactured by any one of claims 1 to 6 with abrasive grains.

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