TW201811975A - Concentrate of composition for rough grinding of wafer - Google Patents

Abstract

The present invention provides a concentrated solution of a silicon wafer rough polishing composition that exhibits good polishing performance after dilution and has excellent stability. The concentrated liquid of the silicon wafer rough polishing composition provided by the present invention includes abrasive particles, an alkaline compound, and a water-soluble polymer. The ratio [rg / d] of the radius of inertia rg [nm] of the water-soluble polymer in the concentrated solution to the inter-particle distance d [nm] of the abrasive particles is 4.7 or less.

Description

Concentrate for silicon wafer rough polishing composition

[0001] The present invention relates to a concentrated solution of a composition for rough polishing of a silicon wafer. This application claims priority based on Japanese Patent Application No. 2016-152324 filed on August 2, 2016, the entire contents of which are incorporated herein by reference.

[0002] The surface of a silicon substrate used in the manufacture of semiconductor products and the like is generally modified into a high-quality mirror surface through a grinding step and a polishing step. The above-mentioned polishing step typically includes a pre-polishing step and a fine polishing step. The pre-polishing step is also referred to as a rough grinding step. The polishing step is also referred to as a fine grinding step. Such a polishing composition may be in a concentrated form before being supplied to the object to be polished from the viewpoint of convenience, cost reduction, and the like during manufacturing, distribution, and storage. That is, the polishing composition may be in the form of a concentrated liquid of a polishing liquid. The prepared concentrate is diluted with water or the like and used for grinding. An example of a document that discloses such a prior art is Patent Document 1. Patent Document 2 discloses a radius of inertia of hydroxycellulose used in a polishing composition. [Prior Art Document] [Patent Document] [0003] [Patent Document 1] Japanese Patent Application Publication No. 2012-89862 [Patent Document 2] Japanese Patent Application Publication No. 2015-124231

[Problems to be Solved by the Invention] 0004 [0004] As a result of reviewing the performance improvement of the composition for rough polishing of silicon wafers, the present inventors have obtained the following insights: the addition of a water-soluble polymer and a larger inertia radius can improve Grinding performance. The polishing performance referred to here is typically flatness such as GBIR (Global Backside Ideal Range). On the other hand, when the radius of inertia of the water-soluble polymer is too large, the stability in the concentrated liquid phase tends to decrease. Specifically, the above-mentioned concentrated liquid contains components such as abrasive particles and water-soluble polymers at a higher concentration than during use, so there is a possibility that good stability cannot be obtained because the contained components are separated and aggregated. If it can provide a polishing composition that is excellent in stability even in the form of a concentrated solution with high concentration and exhibits good polishing performance after dilution, it will be advantageous in terms of convenience, cost reduction, and the like, and it will have practical advantages. [0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a concentrated liquid for a silicon wafer rough polishing composition that exhibits good polishing performance after dilution and has excellent stability. [Means for Solving the Problems] [0007] According to the present invention, a concentrated liquid for a silicon wafer rough polishing composition including abrasive particles, an alkaline compound, and a water-soluble polymer is provided. The ratio [rg / d] of the radius of inertia rg [nm] of the water-soluble polymer in the concentrated solution to the inter-particle distance d [nm] of the abrasive particles is 4.7 or less. The concentrated liquid of this composition shows excellent stability, and can exhibit good grinding performance after dilution. The above-mentioned polishing performance is typically a flatness improving effect.

[0007] Hereinafter, preferred embodiments of the present invention will be described. It is to be noted that the implementation of the present invention other than the matters specifically mentioned in this specification is a person skilled in the art can grasp design matters based on conventional technology in the field. The present invention can be implemented based on the contents disclosed in this specification and technical knowledge in the field. [0008] <Concentrated solution of polishing composition> (Characteristics) 浓缩 The concentrated solution of the polishing composition disclosed herein includes abrasive particles and a water-soluble polymer. Hereinafter, the concentrated liquid of the said polishing composition is abbreviated as "concentrated liquid." Therefore, the concentrated solution is characterized in that the ratio [rg / d] of the radius of inertia rg [nm] of the water-soluble polymer to the inter-particle distance d [nm] of the abrasive particles is 4.7 or less. A concentrated solution satisfying the above characteristics exhibits excellent stability. Although the reason is not specifically explained, it is believed that by satisfying the above ratio [rg / d], the water-soluble polymer in the concentrated liquid can stably exist among the abrasive particles, and the main components of the concentrated liquid can be contained The abrasive particles and water-soluble polymers can be stably dispersed in the concentrated solution. In addition, when the concentrated liquid is diluted and used as a polishing liquid, by containing the water-soluble polymer described above, it is possible to exhibit good polishing performance for a silicon wafer, which is a substrate to be polished. The said polishing performance is a flatness improvement effect specifically. The above-mentioned ratio [rg / d] is preferably 3.8 or less, more preferably 2.8 or less, still more preferably 2.5 or less, and particularly preferably 1.9 or less from the viewpoint of improving stability. In a particularly preferable state, the above-mentioned ratio [rg / d] is typically 1.0 or less. The lower limit of the above-mentioned ratio [rg / d] is not particularly limited, and it may be generally about 0.3 or more, for example, 0.6 or more, from the viewpoints of the concentration efficiency and grinding performance of the concentrate. The interparticle distance [nm] of the abrasive grains and the inertia radius rg [nm] of the water-soluble polymer are measured by the method described later. [0009] (Abrasive particles) 研磨 The abrasive particles disclosed herein are contained in the concentrated liquid with the content of the distance d [nm] between the abrasive particles satisfying the above-mentioned ratio [rg / d]. In a preferred aspect, the inter-particle distance d of the abrasive particles is 200 nm or less. According to the technology disclosed herein, as mentioned above, the inter-particle distance d of the abrasive particles is below a specific value, and the abrasive particles in the concentrated liquid are relatively close to each other, and excellent stability can also be achieved. From the viewpoint of the concentration efficiency of the concentrated liquid, the inter-particle distance d is more preferably 150 nm or less, still more preferably 100 nm or less, and particularly preferably 80 nm or less. In a particularly preferred state, the inter-particle distance d is typically 70 nm or less. In addition, in a range satisfying the above-mentioned ratio [rg / d], the inter-particle distance d may be, for example, 60 nm or less, and further, 40 nm or less. [0010] In addition, the inter-particle distance d [nm] of the abrasive grains in this specification is assumed to be uniform dispersion of the abrasive grains contained in the concentrated liquid, and based on the densest filling rate of the balls [74%], it is obtained from the following formula. Theoretical value: d [nm] = R_s × 2-D1 here, R_s It is the radius [nm] of the sphere which is centered around one abrasive particle and the corresponding sphere of the adjacent abrasive particle. D1 is the average primary particle size [nm] of the abrasive particle. R_s In other words, it is the radius [nm] of the sphere in the concentrated liquid which has the volume of the concentrated liquid distributed to one abrasive particle, and is obtained by the following method. Specifically, the value of the unit volume of a concentrated liquid such as 1L multiplied by the filling rate of 74% is divided by the number of abrasive particles contained in the concentrated liquid per unit volume to obtain the maximum size that an abrasive particle can occupy Volume of the ball V_s , By the formula: V_s = 4/3 × πR_s ³ And find R_s . The number of abrasive particles contained in a concentrated liquid per unit volume is obtained by dividing the weight of the abrasive particles [g / L] per unit volume of the concentrated liquid, for example, by the weight [g] of each abrasive particle. . The weight of the abrasive grains per concentrated liquid per unit volume is determined from the content and specific gravity of the abrasive grain particles in the concentrated fluid, and the content and specific gravity of components other than the abrasive grains contained in the concentrated fluid. The specific gravity of the abrasive particles is 2.2 g / cm when compared to, for example, silica abrasive particles.³ . The components other than the abrasive grains contained in the concentrated liquid usually have an aqueous solvent as the main component. The weight [g] of each abrasive particle is calculated from the average primary particle diameter [nm] of the abrasive particle, and the specific gravity of the ball volume and the abrasive particle when the primary particle is regarded as a true sphere. [0011] In the technology disclosed herein, the material or properties of the abrasive particles contained in the concentrated liquid and the polishing composition obtained by diluting the concentrated liquid are not particularly limited, and may be appropriately selected according to the purpose of use or the use state. Examples of the abrasive particles include inorganic particles, organic particles, and organic-inorganic composite particles. Specific examples of the inorganic particles include silicon oxide particles, aluminum oxide particles, cerium oxide particles, chromium oxide particles, titanium dioxide particles, zirconia particles, magnesium oxide particles, manganese dioxide particles, zinc oxide particles, and iron oxide (Bengala) particles. Oxide particles; nitride particles such as silicon nitride particles and boron nitride particles; carbide particles such as silicon carbide particles and boron carbide particles; diamond particles; carbonates such as calcium carbonate or barium carbonate. Specific examples of the organic particles include polymethylmethacrylate (PMMA) particles, poly (meth) acrylic particles, and polyacrylonitrile particles. These abrasive grains may be used individually by 1 type, and may be used in combination of 2 or more type. The term (meth) acrylic acid includes acrylic acid and methacrylic acid. [0012] The abrasive particles are preferably inorganic particles, and among them, particles made of a metal or semi-metal oxide are preferred. An example of particularly good abrasive particles in the technology disclosed herein is silicon oxide particles. The technique disclosed herein can be better implemented in a state where the above-mentioned abrasive particles are substantially made of silicon oxide particles. The term "substantially" herein means that 95% by weight or more of the particles constituting the abrasive particles, preferably 98% by weight or more, more preferably 99% by weight or more are silica particles, and 100% by weight of the particles constituting the abrasive particles are Silicon oxide particles. [0013] Specific examples of silica include colloidal silica, fumed silica, and precipitated silica. The silica particles can be used singly or in combination of two or more kinds. From the viewpoint that scratches on the surface of the object to be polished are unlikely to occur, and good polishing performance can be exhibited, colloidal silica is particularly preferred. Here, the term "good polishing performance" refers to the performance of reducing the surface roughness and the like. As the colloidal silica, colloidal silica or an alkoxide-based colloidal silica produced by using, for example, water glass as a raw material by an ion exchange method can be preferably used. In addition, water glass means sodium silicate. The so-called alkoxide colloidal silica is colloidal silica produced by the hydrolysis and condensation reaction of an alkoxysilane. Colloidal silica can be used alone or in combination of two or more. [0014] The true specific gravity of the silicon oxide constituting the silicon oxide particles is preferably 1.5 or more, more preferably 1.6 or more, and even more preferably 1.7 or more. By increasing the true specific gravity of silicon oxide, there is a tendency to increase the polishing rate. From this viewpoint, particularly preferred are silica particles having a true specific gravity of 2.0 or more. In a particularly preferred aspect, the true specific gravity is, for example, 2.1 or more. The upper limit of the true specific gravity of silicon oxide is not particularly limited, and is typically 2.3 or less, for example, 2.2 or less. The true specific gravity of silica can be measured by a liquid replacement method using ethanol as a replacement liquid. [0015] The average primary particle diameter of the abrasive particles disclosed herein is not particularly limited. The abrasive particles are typically silicon oxide particles. From the viewpoint of polishing rate and the like, the average primary particle diameter is preferably 5 nm or more, preferably 10 nm or more, more preferably 30 nm or more, still more preferably 40 nm or more, and particularly preferably 45 nm or more. In a particularly preferred embodiment, the average primary particle diameter is, for example, 50 nm or more. From the viewpoint of preventing scratches, etc., the average primary particle diameter of the abrasive grains is preferably 200 nm or less, preferably 100 nm or less, more preferably 80 nm or less, and even more preferably 70 nm or less. In a particularly preferred state, the average primary particle diameter of the abrasive particles is 60 nm or less, and for example, it may be 55 nm or less. In addition, the so-called average primary particle diameter in this specification means the specific surface area (BET value) measured by the BET method, and the BET diameter [nm] = 6000 / (true density [g / cm]³ ] × BET value [m² / g]). Here, the specific surface area measured by the BET method is called a BET value. For example, for silica particles, the BET diameter [nm] = 2727 / BET value [m² / g] Calculate the BET diameter. The measurement of the specific surface area can be performed using, for example, a surface area measuring device manufactured by MICRO MATERIALS, under the trade name "Flow Sorb II 2300". [0016] The shape of the abrasive particles may be spherical or non-spherical. The above shapes are external shapes. Specific examples of the non-spherical particles include a peanut shape, a cocoon shape, a gold candy shape, a football shape, and the like. The peanut shape is the shape of the groundnut shell. For example, abrasive grains whose particles are mostly peanut-shaped can be preferably used. [0017] Although not particularly limited, the average value of the major diameter / minor diameter ratio of the abrasive grains is in principle 1.0 or more, preferably 1.05 or more, and more preferably 1.1 or more. The average value of the major diameter / minor diameter ratio of the abrasive grains is also referred to as the average aspect ratio. By increasing the average aspect ratio, higher grinding rates can be achieved. The average aspect ratio of the abrasive particles is preferably 3.0 or less, more preferably 2.0 or less, and even more preferably 1.5 or less from the viewpoint of reducing scratches and the like. [0018] The shape (outer shape) or average aspect ratio of the abrasive grains can be grasped by, for example, observation with an electron microscope. The specific order of grasping the average aspect ratio is, for example, using a scanning electron microscope (SEM), to draw a smallest rectangle circumscribed on each particle image for a predetermined number of silicon oxide particles that can identify the shape of independent particles. The predetermined number is, for example, 200. Next, for the rectangle drawn on each particle image, the value of the length of the long side (the value of the long diameter) divided by the length of the short side (the value of the short diameter) is used as the length / length ratio (aspect ratio). ). By arithmetically averaging the predetermined aspect ratio of the particles, the average aspect ratio can be obtained. [0019] The content (concentration) of the abrasive particles in the concentrated solution disclosed herein is not particularly limited, but is preferably 50% by weight or more. From the viewpoints of stability, filterability, and the like of the concentrate, the content of the abrasive particles is usually 45% by weight or less, for example, 40% by weight or less, and typically 35% by weight or less is appropriate. The content of the abrasive particles is preferably 30% by weight or less, more preferably 25% by weight or less, and still more preferably 20% by weight or less. In a further preferable aspect, the content of the abrasive particles is, for example, 15% by weight or less. The content of the abrasive particles in the concentrated solution is usually 1% by weight or more, for example, 3% by weight or more, based on the viewpoint of the concentration of the abrasive particles of the polishing composition after dilution or the convenience of manufacturing, distribution, and storage. It is suitable that it is 5 weight% or more. The content of the abrasive particles is preferably 8% by weight or more. In a preferred aspect, the content of the abrasive particles is, for example, 10% by weight or more, and further, 12% by weight or more. [0020] (Water-soluble polymer) 之 The water-soluble polymer contained in the concentrated solution disclosed herein uses a radius of inertia (rg: radius of gyration) that satisfies a ratio [rg / d] of a specific value or less. The polishing slurry containing the water-soluble polymer can sufficiently wet and affinity the substrate to be polished, and as a result, the polishing performance can be improved. The polishing performance here is typically flatness. In addition, the inertia radius rg of the water-soluble polymer is mainly determined by the hydrophilicity and molecular weight of the polymer, and it is the size of one molecule of the water-soluble polymer in the aqueous solution. Since the upper limit value of the inertia radius rg limits the upper limit of the ratio [rg / d], it becomes a limited value in the relative relationship with the distance d between the particles. The inertia radius rg of the homogeneous water-soluble polymer is about 500 nm or less, and about 300 nm or less is appropriate. When a water-soluble polymer having an inertia radius rg of 220 nm or less and more preferably 150 nm or less is used, the above-mentioned ratio [rg / d] can be satisfactorily satisfied. There is also a tendency to improve the concentration efficiency. The inertia radius rg may be about 100 nm or less, and may be, for example, 70 nm or less. In addition, in a preferred embodiment, the inertia radius rg of the water-soluble polymer is 30 nm or more, and more preferably 50 nm or more. From the viewpoint of the wettability of the substrate to be polished, the inertia radius rg is more preferably 80 nm or more, still more preferably 100 nm or more, and particularly preferably 120 nm or more. In a particularly preferred state, the radius of inertia rg is, for example, 140 nm or more. According to the technology disclosed herein, the inertia radius rg of the water-soluble polymer is above a certain value, and the concentrated liquid can also achieve excellent stability. In addition, when a polishing liquid containing a water-soluble polymer having a radius of inertia rg of a specific value or more is used, the wettability to the substrate surface is better exhibited, and the polishing performance tends to be further improved. The polishing performance referred to here is typically flatness. The inertia radius rg of the water-soluble polymer in the present specification can be measured by a method described in Examples described later. [0021] The type of the water-soluble polymer contained in the concentrated liquid disclosed herein is not particularly limited, and it can be appropriately selected from the types of water-soluble polymers known in the field of polishing compositions. The water-soluble polymers can be used singly or in combination of two or more kinds. Examples of the water-soluble polymer include cellulose derivatives, starch derivatives, polymers containing oxyalkylene units, polymers containing nitrogen atoms, and polyvinyl alcohol. Among these, from the viewpoint of improving flatness, cellulose derivatives and starch derivatives are preferred, and cellulose derivatives are more preferred. [0022] Cellulose derivatives are polymers containing β-glucose units as the main repeating unit. Specific examples of the cellulose derivative include hydroxyethyl cellulose (HEC), hydroxypropyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and ethyl cellulose , Ethyl hydroxyethyl cellulose, carboxymethyl cellulose, and the like. Among them, HEC is preferred. [0023] Starch derivatives are polymers containing α-glucose units as the main repeating unit. Specific examples of the starch derivative include alpha starch, pullulan, carboxymethyl starch, cyclodextrin, and the like. Among them, pullulan polysaccharide is preferred. [0024] Polymers containing oxyalkylene units are exemplified by polyethylene oxide (PEO), or blocks of ethylene oxide (EO) and propylene oxide (PO) or with butylene oxide (BO) Copolymers, random copolymers of EO and PO or BO. Among them, a block copolymer of EO and PO or a random copolymer of EO and PO is preferred. The block copolymer of EO and PO may be a diblock body, a triblock body, etc. containing a PEO block and a polypropylene oxide (PPO) block. Examples of the triblock include a PEO-PPO-PEO type triblock and a PPO-PEO-PPO type triblock. Usually it is more preferably a PEO-PPO-PEO type triblock. Among block copolymers or random copolymers of EO and PO, the molar ratio [EO / PO] of EO and PO constituting the copolymer is preferably greater than the viewpoint of solubility in water or detergency. 1, more preferably 2 or more, and even more preferably 3 or more. In a further preferred aspect, the above-mentioned molar ratio [EO / PO] is, for example, 5 or more. [0025] As the nitrogen atom-containing polymer, any one of a polymer containing a nitrogen atom in the main chain and a polymer having a nitrogen atom in a side chain functional group (side chain group) can be used. By using a polymer containing a nitrogen atom, the substrate surface roughness can be improved. Examples of polymers containing a nitrogen atom in the main chain include homopolymers and copolymers of N-fluorenylalkyleneimine-type monomers. Specific examples of the N-fluorenylalkyleneimine-type monomer include N-ethylfluorenylethylimine, N-propylfluorenylethylimine, and the like. Examples of the polymer having a nitrogen atom in the side chain group include, for example, a polymer containing an N-vinyl monomer unit. For example, homopolymers and copolymers of N-vinylpyrrolidone can be used. Among the techniques disclosed herein, at least one of the homopolymers and copolymers of N-vinylpyrrolidone (hereinafter also referred to as " PVP "). [0026] When polyvinyl alcohol is used as the water-soluble polymer, the saponification degree of the polyvinyl alcohol is not particularly limited. [0027] In the technology disclosed herein, the molecular weight of the water-soluble polymer P1 can be appropriately set within a range that satisfies a ratio [rg / d] below a specific value. From the viewpoint of stability or concentration efficiency, the weight average molecular weight (Mw) of the water-soluble polymer can be about 200 × 10⁴ Below, usually 150 × 10⁴ Below, for example, 100 × 10⁴ The following is appropriate. The above Mw may also be, for example, 50 × 10⁴ Below, it can also be 30 × 10⁴ the following. In addition, from the viewpoint of improving the protection or polishing performance of the substrate surface, the Mw is usually 1 × 10⁴ The above is appropriate, more preferably 10 × 10⁴ Above, and more preferably 20 × 10⁴ the above. The Mw is, for example, 50 × 10⁴ Above, can be 100 × 10⁴ the above. The above-mentioned Mw is particularly preferably used for cellulose derivatives. Examples of the cellulose derivative include HEC. [0028] As the Mw of the water-soluble polymer, a value based on a water-based gel permeation chromatography (GPC) (water-based, polyethylene oxide conversion) can be used. [0029] The technology disclosed herein is preferably implemented in a combination of two or more water-soluble polymers. From the viewpoint of both grinding performance (flatness) and surface roughness, it is better to use one or more water-soluble polymers P1 selected from cellulose derivatives and starch derivatives in combination with cellulose derivatives and starch derivatives. One or two or more kinds of water-soluble polymers P2 other than substances. The water-soluble polymer P1 is typically a cellulose derivative such as HEC. The water-soluble polymer P2 is preferably a polymer containing a nitrogen atom in the main chain, a polymer having a nitrogen atom in a side chain functional group (side chain group), and more preferably a monomer unit containing an N-vinyl type. polymer. Among them, particularly preferred are homopolymers and copolymers of N-vinylpyrrolidone (typically PVP) and the like. [0030] In the technology disclosed herein, when the water-soluble polymer P1 and the water-soluble polymer P2 are used in combination, the mixing ratio of the water-soluble polymer P1 and the water-soluble polymer P2 is not particularly limited. For example, the water-soluble polymer P2 is suitable for It is appropriate that the content ratio [P2 / P1] of the water-soluble polymer P1 is 0.1 or more. The ratio [P2 / P1] is, for example, 0.25 or more. The ratio [P2 / P1] is preferably about 10 or less. The above-mentioned ratio [P2 / P1] is, for example, 2.5 or less, and typically does not reach 1. The water-soluble polymer P1 is, for example, a cellulose derivative such as HEC, and the water-soluble polymer P2 is, for example, a polymer including an N-vinyl monomer unit such as PVP. [0031] In a state where water-soluble polymers P1 and P2 are used in combination, the molecular weight of the water-soluble polymer P1 can be appropriately set within a range that satisfies a ratio [rg / d] of a specific value or less. The weight molecular weight (Mw) of the water-soluble polymer P1 may be about 200 × 10 from the viewpoints of stability and concentration efficiency.⁴ Below, usually 150 × 10⁴ Below, for example, 100 × 10⁴ The following is appropriate. The above Mw may also be, for example, 50 × 10⁴ Below, it can be 30 × 10⁴ the following. In addition, from the viewpoint of improving the protection or polishing performance of the substrate surface, the Mw is usually 1 × 10⁴ The above is appropriate, more preferably 10 × 10⁴ Above, and more preferably 20 × 10⁴ the above. The Mw is, for example, 50 × 10⁴ Above, can be 100 × 10⁴ the above. The above-mentioned Mw is particularly preferably used for cellulose derivatives. Examples of the cellulose derivative include HEC. [0032] The molecular weight of the water-soluble polymer P2 is not particularly limited. The weight average molecular weight (Mw) of the water-soluble polymer P2 can be about 300 × 10⁴ Below, usually 150 × 10⁴ Below, for example, 50 × 10⁴ The following is appropriate. From the viewpoint of stability, etc., the above Mw can also be 30 × 10⁴ Below, for example, 5 × 10⁴ the following. In addition, from the viewpoint of improving surface protection, Mw is usually 1 × 10.⁴ The above is appropriate, more preferably 2 × 10⁴ Above, and more preferably 3 × 10⁴ the above. The aforementioned Mw can be particularly preferably used for homopolymers and copolymers of N-vinylpyrrolidone (typically PVP). [0033] The content (concentration) of the water-soluble polymer in the concentrated solution disclosed herein is not particularly limited, and may be set to 0.0001 part by weight or more. From the viewpoint of improvement in polishing performance and the like, the preferred content is 0.001 parts by weight or more, more preferably 0.0025 parts by weight or more, and for example, 0.005 parts by weight or more. The polishing performance is specifically flatness. From the viewpoint of polishing rate and the like, the content is preferably 1 part by weight or less, more preferably 0.2 part by weight or less, still more preferably 0.1 part by weight or less, and particularly preferably 0.05% by weight or less. In a particularly preferred aspect, the content of the water-soluble polymer is, for example, 0.02% by weight or less. [0034] Moreover, the content of the water-soluble polymer in the concentrated liquid disclosed herein can be specified by the relative relationship with the abrasive particles contained in the concentrated liquid. Specifically, the content of the water-soluble polymer is preferably 0.001 part by weight or more relative to 100 parts by weight of the abrasive grains. From the viewpoint of improving the polishing performance, the content is preferably 0.005 part by weight or more, and more preferably 0.01 part by weight. The above is more preferably 0.015 parts by weight or more. In a further preferred aspect, the content of the water-soluble polymer is, for example, 0.03 parts by weight or more based on 100 parts by weight of the abrasive particles. The polishing performance is specifically flatness. In addition, from the viewpoints of stability, polishing rate, and the like, the content of the water-soluble polymer is preferably 10 parts by weight or more relative to 100 parts by weight of the abrasive particles, preferably 1 part by weight or less, and more preferably 0.5 part by weight Hereinafter, it is more preferably 0.1 part by weight or less. In a further preferred aspect, the content of the water-soluble polymer is, for example, 0.05 parts by weight or less based on 100 parts by weight of the abrasive particles. [0035] (Basic Compound) The concentrate disclosed herein contains a basic compound. The term “basic compound” used herein refers to a compound having a function of increasing the pH of an aqueous solution by dissolving it in water. As the basic compound, a nitrogen-containing organic or inorganic basic compound, a hydroxide of an alkali metal, a hydroxide of an alkaline earth metal, various carbonates or bicarbonates, and the like can be used. Examples of the nitrogen-containing basic compound include quaternary ammonium compounds, quaternary amidine compounds, ammonia, amines, and the like. The amine is preferably a water-soluble amine. These basic compounds may be used alone or in combination of two or more. [0036] Specific examples of the hydroxide of the alkali metal include potassium hydroxide, sodium hydroxide, and the like. Specific examples of the carbonate or bicarbonate include ammonium bicarbonate, ammonium carbonate, potassium bicarbonate, potassium carbonate, sodium bicarbonate, sodium carbonate, and the like. Specific examples of the amine include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, monoethanolamine, N- (β-aminoethyl) ethanolamine, and hexamethylene Diamine, diethylene triamine, triethylene tetramine, anhydrous piperazine, piperazine hexahydrate, 1- (2-aminoethyl) piperazine, N-methylpiperazine, guanidine, Imidazole or azoles such as triazole. Specific examples of the quaternary phosphonium compound include quaternary phosphonium hydroxide such as tetramethylphosphonium hydroxide and tetraethylphosphonium hydroxide. [0037] As the quaternary ammonium compound, a quaternary ammonium salt such as a tetraalkylammonium salt, an alkyl trialkylammonium salt, or the like can be preferably used. The above-mentioned quaternary ammonium salt is typically a strong base. The anionic component in the quaternary ammonium salt may be, for example, OH^- , F^- , Cl^- Br^- , I^- ClO₄ ^- , BH₄ ^- Wait. Among them, a preferable example is anionic OH^- The quaternary ammonium salt, that is, quaternary ammonium hydroxide. Specific examples of the quaternary ammonium hydroxide include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrapentylammonium hydroxide, and tetrahexyl hydroxide Tetraalkylammonium hydroxide such as ammonium; 2-hydroxyethyltrimethylammonium hydroxide (also known as choline); hydroxyalkyltrialkylammonium hydroxide and the like. Among these, tetraalkylammonium hydroxide is preferred, and among these, tetramethylammonium hydroxide (TMAH) is preferred. [0038] The concentrate disclosed herein may contain a quaternary ammonium compound as described above and a weak acid salt in combination. Examples of the quaternary ammonium compound include tetraalkylammonium hydroxide such as TMAH. As a weak acid salt, it can be used for grinding using silicon oxide particles, and a suitable buffering effect can be appropriately selected by combining with a quaternary ammonium compound. The weak acid salts can be used alone or in combination of two or more. Specific examples of weak acid salts include sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium orthosilicate, potassium orthosilicate, sodium carbonate, potassium acetate, sodium propionate, potassium propionate, calcium carbonate, Calcium bicarbonate, calcium acetate, calcium propionate, magnesium acetate, magnesium propionate, zinc propionate, manganese acetate, cobalt acetate, and the like. It is preferably a weak acid salt of an anion component type carbonate ion or bicarbonate ion, and particularly preferably a weak acid salt of an anion component type carbonate ion. The cationic component is preferably an alkali metal ion such as potassium or sodium. Particularly preferred weak acid salts include sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate. Among them, potassium carbonate (K₂ CO₃ ). [0039] As a basic compound, when a quaternary ammonium compound and a weak acid salt are used in combination, the mixing ratio of the quaternary ammonium compound and the weak acid salt is not particularly limited, for example, the quaternary ammonium compound: the weak acid salt is set to 1: 9 ~ 9: 1 is appropriate, preferably 3: 7 ~ 8: 2, more preferably 5: 5 ~ 7: 3. The quaternary ammonium compound is, for example, tetraalkylammonium hydroxide such as TMAH. Weak acid salts are for example K₂ CO₃ And other anionic components are weak acid salts of carbonate ions. [0040] The content (concentration) of the basic compound in the concentrated solution disclosed herein is based on the stability of the concentrated solution, the improvement of the polishing rate due to the polishing composition after dilution, and the like, for example, 0.1% by weight or more, Typically, it is appropriate to be 0.3% by weight or more, preferably 0.5% by weight or more, more preferably 0.6% by weight or more, and still more preferably 0.8% by weight or more. In a more preferred embodiment, the content of the basic compound is, for example, 1.0% by weight or more, and typically 1.2% by weight or more. For example, when the concentrated liquid is diluted and used at a high rate, the concentration of the abrasive particles after dilution is relatively low, and the processing power of the abrasive particles may also decrease. In these cases, the chemical grinding after dilution can be enhanced by increasing the amount of basic compounds in the concentrated solution stage. The upper limit of the content of the basic compound in the concentrated solution is preferably 10% by weight or less from the viewpoint of storage stability, surface quality, and the like, and preferably 5% by weight or less. In a preferred aspect, the content of the basic compound is, for example, 3% by weight or less. [0041] In addition, the content of the basic compound in the concentrated solution can also be specified by the relative relationship with the abrasive particles contained in the concentrated solution. Specifically, the content of the basic compound in the concentrate is preferably 0.1 parts by weight or more relative to 100 parts by weight of the abrasive grains. From the viewpoint of improving the polishing rate, it is preferably 1 part by weight or more, more preferably 3 Part by weight or more, more preferably 6 parts by weight or more. The content of the basic compound in the concentrate is, for example, about 12 parts by weight or more, and may be 22 parts by weight or more. From the viewpoints of stability, surface quality, and the like, the content of the basic compound is preferably 50 parts by weight or less with respect to 100 parts by weight of the abrasive grains, and preferably 30 parts by weight or less. The content of the basic compound in the concentrated solution may be, for example, 20 parts by weight or less and 10 parts by weight or less based on 100 parts by weight of the abrasive particles. [0042] (Water) The concentrates disclosed herein typically contain water. Water is preferably ion-exchanged water (deionized water), pure water, ultrapure water, distilled water, or the like. In order to avoid as much as possible hindering the effects of other components contained in the concentrate, the water used is preferably, for example, a total content of transition metal ions of 100 ppb or less. For example, ion exchange resin can be used to remove impurity ions, filtration can be used to remove foreign matter, and distillation can be used to improve the purity of water. In addition, the concentrated solution disclosed herein may optionally further contain an organic solvent that can be mixed with water uniformly. The organic solvent is a lower alcohol, a lower ketone, or the like. Generally, the solvent contained in the concentrate is preferably 90% by volume or more, and more preferably 95% by volume or more. In a better state, 99 to 100% by volume of the solvent contained in the concentrated solution is typically water. In addition, in this specification, the term of an aqueous solvent may be used as a general term including the said solvent and water. [0043] (Chelating Agent) The concentrated solution disclosed herein may contain a chelating agent as an optional ingredient. The chelating agent functions to suppress the contamination of the object to be ground due to the metal impurities by forming the wrong ions with the metal impurities that may be contained in the concentrated solution and capturing them. Examples of the chelating agent include an aminocarboxylic acid-based chelating agent and an organic phosphonic acid-based chelating agent. Examples of amino carboxylic acid-based chelating agents include ethylenediamine tetraacetic acid, sodium ethylenediamine tetraacetate, nitrogen triacetic acid, sodium nitrogen triacetate, ammonium nitrogen triacetate, hydroxyethyl ethylenediamine triacetic acid, and hydroxyl groups. Ethyl ethylenediamine triacetate, diethylene triamine pentaacetic acid, sodium diethylene triamine pentaacetate, triethylene tetraamine hexaacetic acid, and sodium triethylene tetraamine hexaacetate. Examples of the organic phosphonic acid-based chelating agent include 2-aminoethylphosphonic acid, 1-hydroxyethylene-1,1-diphosphonic acid, aminotris (methylenephosphonic acid), and ethylenediamine Methylphosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), ethane-1,1-diphosphonic acid, ethane-1,1,2-triphosphonic acid, ethane-1- Hydroxy-1,1-diphosphonic acid, ethane-1-hydroxy-1,1,2-triphosphonic acid, ethane-1,2-dicarboxyl-1,2-diphosphonic acid, methane hydroxyphosphonic acid, 2-phosphinofluorenylbutane-1,2-dicarboxylic acid, 1-phosphinofluorenylbutane-2,3,4-tricarboxylic acid and α-methylphosphinofluorenylsuccinic acid. Among these, an organic phosphonic acid-based chelating agent is preferred. Among them, preferred are ethylenediamine (methylenephosphonic acid), dimethylethylenetriaminepenta (methylenephosphonic acid), and dimethylethylenetriaminepentaacetic acid. Particularly preferred chelating agents are ethylenediamine (methylenephosphonic acid) and diethylene triaminepenta (methylenephosphonic acid). The chelating agent may be used singly or in combination of two or more kinds. (Other ingredients) The concentrated solution disclosed herein may further contain a surfactant, an organic acid, an organic acid salt, an inorganic acid, an inorganic acid salt, a preservative, and Mold additives and the like are conventional additives that can be used to grind slurry. As the surfactant, various surfactants such as nonionic, anionic, and cationic can be suitably used. Among them, from the viewpoint of preventing the precipitation of water-soluble polymers such as polyvinyl alcohol, a nonionic surfactant is preferred. The above-mentioned polishing slurry is typically a polishing slurry used in a polishing step of a silicon substrate. [0045] The concentrates disclosed herein are preferably substantially free of oxidants. The reason is that when an oxidant is contained in the concentrated solution, the polishing slurry diluted with the concentrated solution is supplied to an object to be polished (here, a silicon substrate), thereby oxidizing the surface of the object to be polished, thereby forming an oxide film. There is a case where the polishing rate is reduced. Specific examples of oxidants referred to herein are hydrogen peroxide (H₂ O₂ ), Sodium persulfate, ammonium persulfate, sodium dichloroisocyanurate, etc. In addition, the fact that the concentrated solution does not substantially contain an oxidant means that at least the oxidant is not intentionally contained. (PH) The pH of the concentrated solution disclosed herein is typically 8.0 or higher, preferably 8.5 or higher, more preferably 9.0 or higher, and even more preferably 9.5 or higher, such as 10.0 or higher, particularly preferably 10.5 or higher. If the pH of the concentrated liquid is increased, the pH of the diluted grinding liquid also becomes high, which tends to improve the grinding performance. On the other hand, from the viewpoint of preventing the dissolution of the abrasive grains and suppressing the reduction in the mechanical polishing action of the abrasive grains, the pH of the concentrated liquid is preferably 12.0 or less, preferably 11.8 or less, and more preferably 11.5 or less. The abrasive particles are, for example, silica particles. [0047] In the technique disclosed herein, the pH of the liquid composition is adjusted by using a pH meter and a standard buffer solution after 3 points correction, and the glass electrode is placed in the composition of the measurement object. You can grasp the value after settling for more than minutes. The liquid composition may be a polishing slurry, a concentrate thereof, or the like. As the pH meter, for example, a glass electrode type hydrogen ion concentration indicator (model F-23) manufactured by Horiba, Ltd. is used. Moreover, the standard buffer solution is phthalate pH buffer pH: 4.01 (25 ° C), neutral phosphate pH buffer pH: 6.86 (25 ° C), carbonate pH buffer pH: 10.01 (25 ° C) ). [0048] The method for preparing the concentrated liquid is not particularly limited. For example, a conventional mixing device such as a wing mixer, an ultrasonic disperser, and a homomixer can be used to mix the components contained in the concentrated liquid. The form of mixing these components is not particularly limited, and for example, all the components may be mixed at a time, or they may be mixed in an appropriately set order. Regarding the polishing composition to be described later, the same mixing method may be appropriately used before and after the dilution of the concentrated solution. [0049] (Dilution) 浓缩 The concentrated solution of the polishing composition disclosed herein is diluted by a factor of more than 5 times on a volume basis to prepare a polishing solution, and then used for rough polishing of the object to be polished. The polishing target substrate is specifically a silicon wafer. Since the concentrated solution diluted at such a specific or higher ratio tends to contain a high concentration of the component, the component is easy to separate and agglutinate, and it is difficult to obtain good stability. In these configurations, the concentrated solution is prepared so that the above-mentioned ratio [rg / d] becomes a specific value or less, so that the concentrated solution exhibits excellent stability. According to the technology disclosed herein, in the composition using a concentrated liquid diluted by a factor of greater than 10 times on a volume basis, the concentrated liquid also exhibits excellent stability, and the diluted polishing composition can achieve good grinding performance. . The above-mentioned dilution ratio may be 15 times or more on a volume basis, for example, 25 times or more. The upper limit of the above-mentioned dilution ratio is not particularly limited, and is about 50 times or less on a volume basis, for example, 40 times or less, and typically 35 times or less. [0050] The above dilution can be performed at a desired point. Typically, the dilution can be performed by adding and mixing the aqueous solvent to the concentrated solution. The aqueous solvent is typically water. As the liquid used for the dilution, from the viewpoints of handleability, workability, and the like, it is preferable to use an aqueous solvent substantially composed of water. Water is typically ion-exchanged water. The aqueous solvent is, for example, an aqueous solvent in which 99.5 to 100% by volume is water. When the water-based solvent is a mixed solvent, only a part of the constituents of the water-based solvent may be added for dilution, or a mixed solvent containing such constituents in an amount ratio different from that of the water-based solvent may be added for dilution. [0051] <Polishing Composition> The polishing composition disclosed herein contains abrasive particles, a water-soluble polymer, and a basic compound contained in the above-mentioned concentrated solution. Moreover, it typically contains water, and may further contain a chelating agent and other components as optional components. As for the specific examples, as described above, the repeated description will not be repeated here. The polishing composition is also referred to as a polishing liquid or a polishing slurry. [0052] The content of the abrasive particles in the polishing composition obtained by diluting the concentrated solution disclosed herein can be determined by the concentration of the abrasive particles and the dilution ratio of the concentrated solution. In the same state, the content is preferably 0.05% by weight or more, more preferably 0.1% by weight or more, and even more preferably 0.3% by weight or more. In a more preferable aspect, the content is, for example, 0.5% by weight or more. By increasing the content of abrasive particles, a higher polishing rate can be achieved. In addition, from the viewpoint of removability from the object to be polished, the content is usually 10% by weight or less, preferably 7% by weight or less, more preferably 5% by weight or less, and still more preferably 3% by weight or less. In a further preferred aspect, the content is, for example, 2% by weight or less. [0053] The content of the water-soluble polymer in the polishing composition is suitably 1 × 10 from the viewpoints of polishing performance, surface quality improvement, and the like.^-5 Above weight%, for example, 5 × 10^-5 Above 1% by weight, preferably 1 × 10^-4 More than% by weight. In a preferred embodiment, the content of the water-soluble polymer is, for example, 2 × 10^-4 More than% by weight. The upper limit of the content of the water-soluble polymer in the polishing composition may be, for example, 1% by weight or less. From the viewpoints of stability, polishing rate, and detergency of the concentrated liquid, the content of the water-soluble polymer is preferably 0.1% by weight or less, more preferably 0.05% by weight or less, and still more preferably 0.02% by weight or less. In a more preferable aspect, the content of the water-soluble polymer is, for example, 0.01% by weight or less, and typically 0.005% by weight or less. [0054] The content of the water-soluble polymer in the polishing composition is preferably 0.001 parts by weight or more relative to 100 parts by weight of the abrasive particles, and is preferably 0.005 parts by weight or more from the viewpoint of improving polishing performance and the like. It is more preferably 0.01 parts by weight or more, and still more preferably 0.015 parts by weight or more. In a more preferable aspect, the content of the water-soluble polymer in the polishing composition is, for example, 0.03 parts by weight or more with respect to 100 parts by weight of the abrasive particles. The polishing performance is specifically flatness. In addition, from the viewpoints of stability, polishing rate, etc., the content of the water-soluble polymer is preferably 10 parts by weight or less with respect to 100 parts by weight of the abrasive grains, preferably 1 part by weight or less, and more preferably 0.5 part by weight Hereinafter, it is more preferably 0.1 part by weight or less. In a more preferable aspect, the content of the water-soluble polymer is, for example, 0.05 parts by weight or less based on 100 parts by weight of the abrasive grains. [0055] In the technology disclosed herein, the content of the basic compound in the polishing composition is, for example, 0.001% by weight or more, typically 0.01% by weight or more is appropriate, and from the viewpoint of increasing the polishing rate, it is preferably 0.05% by weight. The above is more preferably 0.07% by weight or more, and still more preferably 0.09% by mass or more. By increasing the content of basic compounds, stability can also be improved. The upper limit of the content of the basic compound is suitably 5% by weight or less, and from the viewpoint of surface quality and the like, it is preferably 1% by weight or less. In a preferred embodiment, the content of the basic compound is, for example, 0.5% by weight or less, and typically 0.2% by weight or less. [0056] The pH of the polishing composition of the technology disclosed herein is 8.0 or higher, preferably, for example, 8.5 or higher, more preferably 9.0 or higher, and even more preferably 9.5 or higher. In a more preferred embodiment, the pH is, for example, 10.0 or more. Increasing the pH of the polishing liquid tends to increase the polishing rate. The upper limit of the pH of the polishing liquid is not particularly limited, but it is 12.0 or less, preferably 11.5 or less, and more preferably 11.0 or less, from the viewpoint of better polishing the object to be polished. From the viewpoint of improving the surface quality, the pH is more preferably 10.8 or less. In a more preferred embodiment, the pH is, for example, 10.6 or less, and typically 10.5 or less. The above-mentioned improvement in surface quality typically means a reduction in surface roughness. The above-mentioned pH can be preferably applied to a polishing liquid for polishing silicon wafers, for example. The polishing liquid is, for example, a polishing liquid for rough polishing.用途 [0057] (Application) The technology disclosed herein can be applied to polishing with a silicon substrate (especially a silicon wafer) as an object to be polished. A typical example of a silicon wafer referred to herein is a silicon single crystal wafer, such as a silicon single crystal wafer obtained by cutting a silicon single crystal ingot. The polishing target surface in the technology disclosed herein is typically a surface made of silicon. [0058] Prior to the polishing step using the polishing liquid disclosed herein, the above silicon substrate may also be subjected to general processing such as grinding or etching which is more upstream than the rough polishing step, which is applicable to the silicon substrate. In addition, in the technology disclosed herein, after the polishing step using the above-mentioned polishing liquid, a fine polishing step may be performed on the silicon substrate. The above-mentioned fine grinding includes one or more polishing steps. After the final polishing, the silicon wafer is finished into a high-quality mirror surface. The final polishing refers to the final polishing step in the manufacturing process of the object. That is, the final polishing refers to a step in which polishing is not performed after this step. Therefore, the polishing liquid disclosed herein or the concentrated liquid before dilution can be used for polishing silicon wafers after grinding. In addition, the above-mentioned polishing liquid or concentrated liquid can be used for rough polishing before final polishing of a silicon wafer. Rough grinding is also called pre-polishing. [0059] <Polishing> The polishing of the object to be polished can be performed, for example, as follows. That is, the concentrate disclosed herein is diluted to prepare a polishing composition (polishing slurry). Next, this polishing slurry (action slurry) is supplied to an object to be polished, and is polished by a usual method. In the rough polishing of silicon wafers, the grinding object (silicon wafer) that has undergone the grinding step is typically installed in a polishing device. A polishing slurry is supplied to the surface of the object (surface to be polished). Typically, while the polishing slurry is continuously supplied, the polishing pad is pressed against the surface of the object to be polished to move the two relative to each other. The above-mentioned movement may be, for example, a rotational movement. After the polishing step, polishing of the object to be polished is completed. [0060] The polishing pad used in the above polishing step is not particularly limited. For example, a polishing pad of foamed polyurethane type, non-woven type, suede type, or the like can be used. Each polishing pad may or may not contain abrasive particles. [0061] As the polishing device, a double-sided polishing device that simultaneously grinds both sides of the object to be polished can be used, or a single-sided polishing device that grinds only one surface of the polishing object can be used. Although not particularly limited, for example, a double-sided polishing device can be preferably used in the rough polishing step. The double-sided polishing device is, for example, a batch-type double-sided polishing device. The grinding device may be a single-piece grinding device configured to grind one grinding object at a time, or a batch grinding device capable of simultaneously grinding multiple grinding objects on the same platen. [0062] <Washing> The object to be polished after the rough grinding step is typically washed before the fine grinding step is started. This washing | cleaning can be performed using an appropriate washing | cleaning liquid. The cleaning liquid used is not particularly limited, and for example, general SC-1 cleaning liquid, SC-2 cleaning liquid, etc. in the field of semiconductors and the like can be used. SC-1 washing liquid system ammonium hydroxide (NH₄ OH) and hydrogen peroxide (H₂ O₂ ) And water (H₂ O) of the mixture). SC-2 washing liquid system HCl, H₂ O₂ With H₂ O of mixed solution. The temperature of the cleaning liquid may be, for example, a range of room temperature or higher and at most about 90 ° C. The so-called room temperature here typically refers to about 15 ° C to 25 ° C. From the viewpoint of improving the cleaning effect, a cleaning solution of about 50 ° C to 85 ° C can be preferably used. [0063] After the rough grinding step, the washing step, and the fine grinding step as described above, the grinding of the object to be polished is completed. The above-mentioned object to be polished is a silicon substrate, and is typically a silicon single crystal wafer. Therefore, according to this specification, a method for manufacturing an abrasive including the above-mentioned polishing step is provided. The above-mentioned manufacturing method is specifically a manufacturing method of a silicon wafer. [0064] As described above, according to this embodiment, a concentrated liquid for a silicon wafer rough polishing composition including abrasive particles, an alkaline compound, and a water-soluble polymer is provided. The ratio [rg / d] of the radius of inertia rg [nm] of the water-soluble polymer in the concentrated solution to the inter-particle distance d [nm] of the abrasive particles is 4.7 or less. The concentrated liquid of this constitution shows excellent stability, and can exhibit good grinding performance after dilution. The above polishing performance is typically a flatness improving effect. [0065] In a preferred aspect of the concentrated liquid disclosed herein, the aforementioned ratio [rg / d] is 2.5 or less. With this configuration, more excellent stability is achieved. [0066] In a preferred aspect of the concentrated liquid disclosed herein, the inter-particle distance d of the aforementioned abrasive particles is 200 nm or less. According to the technology disclosed herein, as mentioned above, the inter-particle distance d of the abrasive particles is below a specific value, and excellent stability can also be achieved. In addition, as described above, a concentrated liquid having a distance d between particles of less than a specific value can be concentrated to a high concentration, and thus it is advantageous in terms of convenience and cost reduction. [0067] In a preferred aspect of the concentrated solution disclosed herein, the inertia radius rg of the aforementioned water-soluble polymer is 30 nm or more. According to the technology disclosed herein, as mentioned above, the radius of inertia of the water-soluble polymer is above a certain value, and the concentrated liquid can also achieve excellent stability. Moreover, as mentioned above, a polishing liquid having a radius of inertia of a water-soluble polymer of a certain value or more can exhibit more excellent polishing performance. The above polishing performance is typically a flatness improving effect. [0068] In a preferred aspect of the concentrated liquid disclosed herein, the concentration of the aforementioned abrasive particles is 5% by weight or more. According to the technology disclosed herein, as mentioned above, the concentration of the abrasive particles is a certain value or more, and excellent stability can also be achieved. In addition, as described above, the concentrated liquid having a concentration of abrasive particles of a specific value or more can be concentrated to a high concentration, which is advantageous in terms of convenience or cost reduction. [0069] In a preferred aspect of the concentrated liquid disclosed herein, the concentration of the aforementioned water-soluble polymer is in the range of 0.001 to 0.05% by weight. When the concentration of the water-soluble polymer is in the above range, the concentrated liquid tends to have excellent stability, and it is easy to exhibit better polishing performance after dilution. [0070] In the preferred embodiment disclosed herein, it is used for rough polishing of silicon wafers on a volume basis, diluted at a rate greater than 10 times. According to the technology disclosed herein, the stability of the concentrated liquid is excellent even if the dilution method is a high concentration ratio. In addition, it is advantageous from the viewpoint of convenience or cost reduction to concentrate the concentrate to a specific concentration or more as described above. [0071] In the typical state disclosed herein, the aforementioned concentrated liquid is used for polishing the polished silicon wafer. More specifically, the aforementioned concentrated solution is used in rough grinding (pre-polishing) performed before the final polishing of the silicon wafer. Rough grinding is also called pre-polishing. [Embodiments] [0072] Hereinafter, several embodiments related to the present invention will be described, but it is not intended to limit the present invention to those shown in the embodiments. In addition, "%" in the following description is a weight basis unless there is particular notice. [Experiment 1] <Examples 1-1 to 1-11 and Comparative Example 1-1> [Preparation of Concentrated Liquid of Polishing Composition] Colloidal silica (average primary particle diameter of 54 nm) as abrasive particles , Water-soluble polymers (HEC, PVP), TMAH, K₂ CO₃ It was mixed with ion-exchanged water to prepare concentrated liquids of the polishing compositions of Examples 1-1 to 1-11 and Comparative Example 1-1, respectively. The concentrations of abrasive particles and water-soluble polymers in the concentrates of each example are shown in Table 1. TMAH and K₂ CO₃ The concentrations were 1.62% and 1.05%, respectively. For each of the concentrated solutions, the inter-particle distance d [nm] of the abrasive particles was determined, and the inertia radius rg [nm] of the water-soluble polymer was measured by the following method. From the obtained value, the ratio [rg / d] of the radius of inertia rg [nm] of the water-soluble polymer to the inter-particle distance d [nm] of the abrasive grains was obtained. The inter-particle distance d [nm] of the abrasive particles, the inertial radius rg [nm], and the ratio [rg / d] of the water-soluble polymer in each example are shown in Table 1. [Measurement method of the radius of inertia] 之 The measurement of the radius of inertia rg of the water-soluble polymer is to first prepare an aqueous solution so that the concentration of the water-soluble polymer is in the range of 0.1 to 1 mg / mL, and use light for each sample prepared. The scattering photometer "DLS-8000" (manufactured by Otsuka Electronics Co., Ltd.) measures every 10 degrees in a range of 20 to 150 degrees from the measurement angle, and calculates the radius of inertia [nm] by a 1-concentration mapping analysis. When a plurality of water-soluble polymers are contained in the concentrated liquid of the polishing composition, the water-soluble polymers are adjusted so that the concentration ratio becomes a measurement. [Stability] 100 Put 100 g of the concentrated solution of each case into a glass tube with a diameter of 2.5 cm and a height of 25 cm, and store it at 25 ° C. The presence or absence of separation of the water-soluble polymer in the above-mentioned concentrated liquid after the lapse of 24 hours from the start of storage was evaluated visually with the following 5 criteria. That is, when no separation of the water-soluble polymer in the liquid is seen, it is evaluated as "A". When separation is seen, it is evaluated as "B" when the layer of the upper liquid is less than 2 mm, and the layer on the upper liquid is 2 mm or more. When it is less than 4 mm, it is evaluated as "C", when the layer of the upper liquid is 4 mm or more and less than 5 mm, it is evaluated as "D", and when the layer of the upper liquid is 5 mm or more, it is evaluated as "E". A to D are practically acceptable, and E is regarded as unacceptable. The results are shown in Table 1. [0076][Experiment 2] <Examples 2-1 to 2-14 and Comparative Examples 2-1 to 2-2> [Preparation of Concentrated Liquid of Polishing Composition] 矽 Colloidal silicon oxide as abrasive particles (on average once) 54nm), water-soluble polymers (HEC, PVP, PVA), TMAH, K₂ CO₃ It was mixed with ion-exchanged water to prepare concentrated liquids of the polishing compositions of Examples 2-1 to 2-14 and Comparative Examples 2-1 to 2-2, respectively. The concentrations of abrasive particles and water-soluble polymers in the concentrated liquid of each example are shown in Table 2. TMAH and K₂ CO₃ It is added to the concentrated solution so that the diluted polishing composition (polishing liquid) becomes 0.067% and 0.043%, respectively. For the polishing composition of Example 2-14, polyoxyethylene lauryl ether as a nonionic surfactant was added to a concentration of 0.001%. For each concentrated solution, the inter-particle distance d [nm] of the abrasive particles was obtained, and the inertia radius rg [nm] of the water-soluble polymer was measured in the same manner as in Experiment 1. From the obtained value, the water-soluble polymer was determined. The ratio [rg / d] of the inertia radius rg [nm] to the inter-particle distance d [nm] of the abrasive particles. The stability of the concentrated liquid was also evaluated in the same manner as in Experiment 1. Table 2 shows the evaluation results of the distance d [nm] between the particles, the radius of inertia rg [nm] of the water-soluble polymer, the ratio [rg / d], and the stability of the concentrated liquid. [0078] [Grinding of Silicon Wafer] The concentrated liquid of each example was diluted with ion exchange water at the dilution ratio (volume basis) shown in Table 2 to obtain a polishing liquid (acting slurry). Using this polishing liquid, rough polishing was performed under the following conditions. (Grinding conditions) Grinding device: Single-side grinder manufactured by THINKY, Japan, model "EJ-380IN" Grinding pad: Made by NITTA HAAS, trade name "MH S-15A" Grinding pressure: 26.6kPa Slurry flow rate: 100mL / Number of platen rotations per minute: 50rpm 数 Number of rotations of indenter: 50rpm Grinding amount: 8μm 种类 Work type: bare silicon P^- <100> Workpiece size: □ 60mm × 60mm [0079] [Grinding performance (flatness)] As a substitute for GBIR evaluation, flatness was evaluated by the following method. Specifically, an evaluation machine "DIGIMICRO MH-15M" manufactured by NIKON was used to measure the thickness of 36 points on the polished wafer surface at 6 points in the vertical and horizontal directions, and define the difference between the maximum and minimum values. The difference in wafer thickness was evaluated based on the following four criteria. That is, when the wafer thickness difference is less than 2.5 μm, the evaluation is “A”, when the wafer thickness difference is 2.5 μm or more and less than 3.0 μm, the evaluation is “B”, and the wafer thickness difference is 3.0 μm or more and 3.2 μm or less. The evaluation was "C" at the time of evaluation, and "D" when the wafer thickness difference was more than 3.2 μm. A to C are practically acceptable, and D is considered to be unacceptable. The results are shown in Table 2. [Polishing performance (surface roughness Ra)] For each example of the silicon wafer after rough polishing (a test piece after rough polishing and subsequent cleaning), a non-contact surface shape measuring machine (trade name "NewView 5032 ", manufactured by Zygo), and measures the surface roughness Ra (arithmetic average surface roughness). The obtained measured value was converted into a relative value with the surface roughness Ra of Comparative Example 2-1 set to 100%, and evaluated in the following two stages. The results are shown in Table 2. A: less than 100% B: more than 100% 008 [0081] [Concentration efficiency] The dilution ratio of the concentrated solution in each case is regarded as the concentration efficiency (concentration ratio can be concentrated), and it is classified by the following three criteria. That is, "A" is recorded when the condensable magnification is greater than 20 times, "B" is recorded when the condensable magnification is greater than 10 times and 20 times or less, and "C" is recorded when the condensable magnification is 10 times or less. The results are shown in Table 2. [0082]As shown in Table 1, in Experiment 1, the ratio [rg / d] of the radius of inertia rg [nm] of the water-soluble polymer to the inter-particle distance d [nm] of the abrasive grains [rg / d] is 4.7 or less The concentrated solution of -1 ~ 1-11 is evaluated as qualified for stability. In particular, in Examples 1-1 to 1-7 and 1-11 in which the above-mentioned ratio [rg / d] is 2.5 or less, the stability evaluation result is A or B, and more excellent stability can be achieved. On the other hand, in Comparative Example 1-1 in which the above-mentioned ratio [rg / d] was greater than 4.7, the stability of the concentrated liquid was a degree of failure. [0084] In addition, as shown in Table 2, in Experiment 2, the above-mentioned ratios [rg / d] of the concentrated liquids of Examples 2-1 to 2-14, which were 4.7 or less, were evaluated for stability. In particular, in Examples 2-1 to 2-10, 2-13, and 2-14 in which the above-mentioned ratio [rg / d] is 2.5 or less, the stability evaluation result is A or B, and more excellent stability can be achieved. On the other hand, in Comparative Example 2-1 in which the above-mentioned ratio [rg / d] was greater than 4.7, the stability of the concentrated liquid was unacceptable. In addition, in Examples 2-1 to 2-14 using a water-soluble polymer, the polishing performance (specifically, flatness) was all acceptable. In contrast, Comparative Example 2-2 without using a water-soluble polymer could not be obtained. Good polishing performance (specifically flatness). [0085] Above, although specific examples of the present invention have been described in detail, these are merely examples and do not limit the scope of patent applications. The technology described in the scope of the patent application includes various modifications and changes of the specific examples illustrated above.

Claims (7)

A concentrated liquid of a composition for rough polishing of a silicon wafer, which comprises abrasive particles, an alkaline compound, and a water-soluble polymer. 半径 The inertia radius rg [nm] of the water-soluble polymer in the concentrated solution is relative to the polishing. The ratio [rg / d] of the distance d [nm] between the particles is 4.7 or less. For example, the concentrate of claim 1, wherein the aforementioned ratio [rg / d] is 2.5 or less. For example, the concentrated solution of claim 1 or 2, wherein the inter-particle distance d of the aforementioned abrasive particles is 200 nm or less. The concentrated liquid according to any one of claims 1 to 3, wherein the inertia radius rg of the water-soluble polymer is 30 nm or more. The concentrated liquid of any one of claims 1 to 4, wherein the concentration of the aforementioned abrasive particles is 5% by weight or more. For example, the concentrated solution of any one of claims 1 to 5, wherein the concentration of the aforementioned water-soluble polymer is in the range of 0.001 to 0.05% by weight. For example, the concentrated liquid of any one of claims 1 to 6, which is diluted on a volume basis by a factor of more than 10 times, is used for rough grinding of silicon wafers.