JP6134644B2 - Composition for polishing edge of substrate and method for polishing edge of substrate using the same - Google Patents

Description

  The present invention relates to an edge polishing composition mainly used in applications for polishing an edge of a substrate such as a silicon wafer, and a substrate edge polishing method using the polishing composition.

  In the substrate manufacturing process, the surface of a substrate obtained by slicing an ingot is formed by lapping. After removing the damage layer generated on the substrate surface by slicing or lapping by etching, the purpose is to prevent the generation of particles from the edge by preventing cracking, chipping and chipping at the edge of the substrate, and during epitaxial growth In order to suppress the generation of edge crowns, it is common practice to chamfer and further polish the edge of the substrate. Edge crown refers to a phenomenon in which when an epitaxial layer is grown on a substrate, the epitaxial layer is formed so as to rise in the peripheral portion of the substrate rather than the central portion of the substrate.

  In general, after the edge polishing, primary polishing, secondary polishing, and finish polishing are performed on the substrate surface in order to finish the substrate surface into a mirror surface. In some cases, secondary polishing may be omitted, or another polishing step may be added between the secondary polishing and the final polishing.

  Edge polishing is generally performed using an edge polishing composition containing a basic compound in order to achieve a high polishing rate (see, for example, Patent Documents 1 and 2). However, the basic compound may cause roughness on the edge or surface of the substrate due to excessive etching.

JP 2000-158329 A JP 2006-114713 A

  Accordingly, the main object of the present invention is to provide an edge polishing composition capable of suppressing roughness generated on the edge and surface of a substrate due to a basic compound, in addition to realizing a high polishing rate. is there.

  The inventors of the present invention have repeatedly studied materials useful for suppressing roughness of the edge and surface of the substrate. As a result, it was found that roughening of the edge and the surface of the substrate was suppressed by containing the substance adsorbing on the edge and the surface of the substrate in the edge polishing composition. On the other hand, it was also found that when a substance adsorbing on the edge or surface of the substrate was included in the edge polishing composition, the etching effect of the basic compound on the edge of the substrate was weakened, resulting in a decrease in the edge polishing rate. . However, when a synthetic water-soluble polymer having a pendant or terminal repeating ring at the side chain or terminal is contained in the edge polishing composition, the polishing rate of the edge of the substrate does not decrease, The inventors have experimentally found that the roughness of the edge and the surface of the substrate is suppressed, and have reached the present invention.

That is, in order to achieve the above object, in one embodiment of the present invention, 0.0001% by mass or more of a synthetic water-soluble polymer (excluding an average molecular weight of 3000 or less) having a heterocyclic ring at a side chain or a terminal, Provided is an edge polishing composition containing at least one selected from imidazole and imidazole derivatives as water-soluble compounds and water.

  In another embodiment of the present invention, a method for polishing a substrate comprising polishing the edge of the substrate using the edge polishing composition according to the one embodiment, and a step of polishing the edge of the substrate using the polishing method. A method is provided.

  ADVANTAGE OF THE INVENTION According to this invention, in addition to implement | achieving a high grinding | polishing rate, the composition for edge grinding | polishing which can suppress the roughness which arises on the edge and surface of a board | substrate due to a basic compound is provided. Moreover, in addition to being able to polish the edge of the substrate at a high polishing rate, an edge polishing method and a substrate manufacturing method that can obtain a substrate with little roughness on the edge or surface in a short time are provided.

  Hereinafter, an embodiment of the present invention will be described.

  The edge polishing composition of the present embodiment contains a synthetic water-soluble polymer having a heterocyclic ring at the side chain or terminal, a basic compound, and water.

<Synthetic water-soluble polymer having a heterocyclic ring at the side chain or terminal>
In the present specification, the “synthetic water-soluble polymer” means that it is not a naturally derived water-soluble polymer such as a cellulose derivative or starch. Naturally derived water-soluble polymers are difficult to obtain in a desired structure and molecular weight because the structure and molecular weight depend on the raw materials. In contrast, a synthetic water-soluble polymer can be easily controlled in structure and molecular weight.

  A synthetic water-soluble polymer having a heterocyclic ring in the side chain or terminal has an action of adsorbing to the edge or surface of the substrate, and the edge or surface of the substrate is excessively etched by the basic compound in the edge polishing composition. Prevent receiving. As a result, the occurrence of roughness on the edge and surface of the substrate is suppressed.

  The heterocyclic ring contained in the synthetic water-soluble polymer in the edge polishing composition includes, for example, monosaccharides such as pentose and hexose, pyrrolidine, tetrahydrofuran, tetrahydrothiophene, azole, furan, thiophene, piperidine, tetrahydropyran, and tetrahydrothiopyran. , Heterocycles such as lactams such as pyridine, hexamethyleneimine, hexamethylene oxide, hexamethylene sulfide, azatropyrideneoxycycloheptatriene, tiotropylidene, pyrazole, imidazole, benzimidazole, γ-lactam, δ-lactam, ε-caprolactam It is derived from a compound. Among these, a tetrahydrofuran ring, a tetrahydropyran ring, a hexamethylene oxide ring, a γ-lactam ring, a δ-lactam ring, and an ε-caprolactam ring are preferable.

  The synthetic water-soluble polymer having a heterocyclic ring at the side chain or terminal may be any of cationic, nonionic, and anionic. Further, it may be a homopolymer or copolymer containing a monomer having a heterocyclic ring as a repeating unit, or a homopolymer or copolymer containing a monomer having no heterocyclic ring as a repeating unit and a heterocyclic ring. It may be an addition reaction product with a compound having the same. Although it does not specifically limit, It is preferable that it is a homopolymer or a copolymer containing any one of polyalkylene or polyoxyalkylene more specifically.

  Specific examples of the synthetic water-soluble polymer having a heterocyclic ring at the side chain or terminal include polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopaltimate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate , Polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitol tetraoleate, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyvinyl imidazole, polyvinyl pyrrolidone, polyvinyl caprolactam, polyvinyl pipette Examples include redone. Of these, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopaltimate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate Oxyethylene sorbitan, polyoxyethylene sorbite tetraoleate, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyvinyl pyrrolidone, polyvinyl caprolactam, and polyvinyl piperidone.

  The content of the synthetic water-soluble polymer in the edge polishing composition is essential to be 0.0001% by mass or more, and preferably 0.0003% by mass or more. When this content is less than 0.0001% by mass, the effect of suppressing the roughness of the edge and surface of the substrate is not sufficiently exhibited.

  Further, the content of the synthetic water-soluble polymer in the edge polishing composition is preferably 0.0015% by mass or less, more preferably 0.0012% by mass or less in order to achieve a high polishing rate. More preferably, it is 0.001 mass% or less. As this content decreases, the polishing rate of the edge polishing composition is improved.

  The weight average molecular weight in terms of polyoxyethylene of the synthetic water-soluble polymer in the edge polishing composition is preferably 1,000 or more, more preferably 8,000 or more. As the weight average molecular weight increases, the effect of suppressing roughness of the edge and surface of the substrate is improved.

  Moreover, it is preferable that the polyoxyethylene conversion weight average molecular weight of the synthetic water-soluble polymer in the edge polishing composition is 1,200,000 or less, more preferably 900,000 or less. As the weight average molecular weight decreases, the dispersion stability of the edge polishing composition improves.

<Basic compound>
The basic compound contained in the edge polishing composition has an action of etching the edge of the substrate and chemically polishes the semiconductor substrate.

  Specific examples of basic compounds include ammonia, potassium hydroxide, sodium hydroxide, potassium bicarbonate, potassium carbonate, sodium bicarbonate, sodium carbonate, tetramethylammonium hydroxide, tetraethylammonium hydroxide, ammonium bicarbonate, ammonium carbonate. , Tetramethylammonium carbonate, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, monoethanolamine, N- (β-aminoethyl) ethanolamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, guanidine, guanidine Carbonate, guanidine hydrochloride, aminoguanidine, aminoguanidine carbonate, aminoguanidine hydrochloride, biguanide, biguanide carbonate Biguanide hydrochloride, sulfamate salt of guanidine, anhydrous piperazine, piperazine hexahydrate, 1- (2-aminoethyl) piperazine, N- methylpiperazine, imidazole, and imidazole derivatives. In the imidazole derivative, for example, at least one of a nitrogen atom at the 1st position, a carbon atom at the 2nd position, a carbon atom at the 4th position, and a carbon atom at the 5th position of the imidazole ring is methyl or ethyl. It may be substituted by an alkyl group such as a group, a hydroxy group, a carboxy group, or an amino group. For the purpose of suppressing metal contamination of the substrate by the edge polishing composition, tetramethylammonium hydroxide, potassium hydroxide, sodium hydroxide, potassium bicarbonate, potassium carbonate, sodium bicarbonate, sodium carbonate, ammonia, ammonium bicarbonate, Alternatively, it is preferable to use ammonium carbonate. These basic compounds may be used alone or in combination of two or more.

  The content of the basic compound in the edge polishing composition is preferably 0.1% by mass or more, more preferably 0.25% by mass or more, and further preferably 0.5% by mass or more. . As this content increases, the polishing rate of the edge polishing composition is improved.

  Further, the content of the basic compound in the edge polishing composition is preferably 10.0% by mass or less, more preferably 6.0% by mass or less. As this content decreases, the dispersion stability of the edge polishing composition improves.

<Water>
The water contained in the edge polishing composition serves to dissolve or disperse other components in the edge polishing composition. It is preferable that water does not contain impurities that inhibit the action of other components as much as possible. Specifically, ion-exchanged water obtained by removing foreign ions through a filter after removing impurity ions using an ion-exchange resin, or pure water, ultrapure water, or distilled water is preferable.

<Abrasive>
The edge polishing composition may further contain abrasive grains. The abrasive grains serve to mechanically polish the edge of the substrate.

  Examples of abrasive grains that can be used in the edge polishing composition include silicon carbide, silicon dioxide, alumina, ceria, zirconia, diamond, boron carbide, boron nitride, and the like. Of these, the use of silicon dioxide is preferable because it hardly causes scratches on the edge and surface of the substrate. Examples of silicon dioxide abrasive grains include colloidal silica, fumed silica, and sol-gel silica. An abrasive grain may be used individually by 1 type, or may be used in combination of 2 or more type.

  The content of the abrasive grains in the edge polishing composition is preferably 1% by mass or more, and more preferably 1.5% by mass or more. As this content increases, the polishing rate of the edge polishing composition is improved.

  Moreover, it is preferable that content of the abrasive grain in the composition for edge polishing is 60 mass% or less, More preferably, it is 40 mass% or less. As this content decreases, the dispersion stability of the edge polishing composition improves.

<Chelating agent>
The edge polishing composition may further contain a chelating agent. When the chelating agent is contained, metal contamination of the substrate by the edge polishing composition can be suppressed.

  Examples of chelating agents that can be used in the edge polishing composition include aminocarboxylic acid chelating agents and organic phosphonic acid chelating agents. Examples of aminocarboxylic acid chelating agents include ethylenediaminetetraacetic acid, ethylenediaminetetraacetic acid sodium, nitrilotriacetic acid, sodium nitrilotriacetic acid, ammonium nitrilotriacetate, hydroxyethylenediaminetriacetic acid, hydroxyethylethylenediaminetriacetic acid, hydroxyethylethylenediaminetriacetic acid Examples include sodium, diethylenetriaminepentaacetic acid, sodium diethylenetriaminepentaacetate, sodium triethylenetetraminehexaacetic acid and sodium triethylenetetraminehexaacetate, diaminopropanoltetraacetic acid, glycol etherdiaminetetraacetic acid. Examples of organic phosphonic acid chelating agents include 2-aminoethylphosphonic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, aminotri (methylenephosphonic acid), ethylenediaminetetrakis (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphone). 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-dicarboxy-1,2-diphosphonic acid, methanehydroxyphosphonic acid, 2-phosphonobutane-1,2-dicarboxylic acid, 1-phosphonobutane-2,3,4-tricarboxylic acid, and α-methyl Examples include phosphonosuccinic acid. Among them, preferable chelating agents are ethylenediaminetetrakis (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), triethylenetetramine hexaacetic acid, triethylenetetramine hexaacetic acid sodium, and most preferable ethylenediaminetetrakis (methylenephosphonic acid), Ethylenetetramine hexaacetic acid. A chelating agent may be used individually by 1 type, or may be used in combination of 2 or more type.

<Wetting agent>
The edge polishing composition may further contain a wetting agent. The wetting agent has an effect of increasing the hydrophilicity (wetting property) of the edge or surface of the substrate. If the hydrophilicity of the edge or surface of the substrate is low, the components in the polishing composition, particularly basic compounds, act unevenly on the edge or surface of the substrate, resulting in roughening of the edge or surface of the substrate. May occur. Further, when the hydrophilicity of the edge or surface of the substrate is low, the edge polishing composition tends to remain on the substrate after edge polishing, and the detergency may deteriorate.

  Examples of wetting agents that can be used in the edge polishing composition include, but are not limited to, substances having a hydroxyl group such as water-soluble polymers and alcohols. Examples of water-soluble polymers that can be used as wetting agents include cellulose derivatives such as hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, polysaccharides such as starch, cyclodextrin, trehalose, pullulan, vinyl polymers such as polyvinyl alcohol, Examples include polyacrylamide, polymethyl methacrylate, polymethyl acrylate, polyoxyalkylene homopolymer, polyoxyalkylene copolymer, and the like. Examples of alcohols that can be used as a wetting agent include straight chain or branched chains having 1 to 6 carbon atoms such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, tert-butanol, pentanol, and hexanol. Aliphatic saturated alcohol, glycerin and the like. As the wetting agent, one kind may be used alone, or two or more kinds may be used in combination.

  The content of the water-soluble polymer used as the wetting agent in the edge polishing composition is preferably 0.001% by mass or more, and more preferably 0.01% by mass or more. As this content increases, it becomes easier to sufficiently enhance the hydrophilicity of the edge and surface of the substrate by the edge polishing composition.

  The content of the water-soluble polymer used as a wetting agent in the edge polishing composition is preferably 1% by mass or less, more preferably 0.5% by mass or less. As this content decreases, the dispersion stability of the edge polishing composition improves. Moreover, the polishing rate of the edge polishing composition is also improved.

  The content of the alcohol used as the wetting agent in the edge polishing composition is preferably 0.005% by mass or more, and more preferably 0.02% by mass or more. As this content increases, it becomes easier to sufficiently enhance the hydrophilicity of the edge and surface of the substrate by the edge polishing composition.

  The content of the alcohol used as the wetting agent in the edge polishing composition is preferably 0.5% by mass or less, more preferably 0.2% by mass or less, and still more preferably 0.8%. 04% by mass or less. As this content decreases, the dispersion stability of the edge polishing composition improves.

  The pH of the edge polishing composition is preferably 9.0 to 13.0, more preferably 9.5 to 11.4. When the pH of the edge polishing composition is in the above range, it is easy to obtain a polishing rate at a particularly suitable level for practical use. In order to obtain a desired pH, a pH adjusting agent may be used. It is also possible to use the basic compound explained above as a pH adjuster.

  The edge polishing composition may further contain known additives such as preservatives, bactericides, surfactants, dispersants and antifoaming agents as necessary.

  When the edge of the substrate is polished using the edge polishing composition of the present embodiment, it is possible to suppress the occurrence of roughness on the edge or surface of the substrate. A substrate having a surface can be obtained.

  In addition to being able to achieve a high polishing rate by using the edge polishing composition of the present embodiment, the reason why it is possible to suppress the occurrence of roughness on the edge and surface of the substrate has not been clearly clarified. However, it is estimated as follows. In other words, the reason why it is possible to suppress the occurrence of roughness on the edge or surface of the substrate is that the synthetic water-soluble polymer having a heterocyclic ring at the side chain or terminal adsorbs to the edge or surface of the substrate, resulting from excessive etching with a basic compound. This is considered to protect the edge and surface of the substrate. On the other hand, the reason why high polishing rate can be realized is that the synthetic water-soluble polymer adsorbed on the edge of the substrate is easily removed from the edge by the physical force applied to the edge during edge polishing, so that the etching action by the basic compound This is probably because it is not overly disturbed.

The substrate that is edge-polished using the edge-polishing composition of the present embodiment is not particularly limited, but is, for example, a semiconductor substrate or a magnetic substrate, and more specifically, a silicon substrate, a SiO ₂ substrate, or an SOI substrate. A silicon nitride substrate, a plastic substrate, a glass substrate, a quartz substrate, an aluminum substrate, and the like. Among these, it is particularly preferable to apply the edge polishing composition of the present embodiment to a silicon wafer that requires high smoothness and cleanliness of edges and surfaces.

  In the case of a single crystal substrate, a notch or an orientation flat may be provided at the edge of the substrate for the purpose of expressing the orientation of the single crystal. The notch is formed by cutting a part of the edge. The cross-sectional shape of the notch is generally U-shaped or V-shaped. The orientation flat is formed by cutting a part of the substrate into a half-moon shape. In general, when a substrate having a notch or an orientation flat is polished with the polishing composition, the polishing composition is more likely to adhere to the notch or orientation flat portion than to the other portion of the edge. Therefore, the notch or the orientation flat part is particularly prone to roughening. However, when the edge polishing composition of the present embodiment is used, the roughness generated in the notch or orientation flat portion can be suppressed, and the finish is comparable to other portions of the edge.

  The edge polishing composition of the present embodiment can be used in the same apparatus and conditions that are normally used in general substrate edge polishing. In general, the substrate is held by a holder, and the polishing pad disposed perpendicularly or obliquely to the substrate surface is pressed against the edge of the substrate while supplying the edge polishing composition to the polishing pad. And rotate the polishing pad in the circumferential direction of the edge. At this time, by the physical action by the abrasive grains in the polishing pad and the edge polishing composition rub against the edge of the substrate, and the chemical action that the basic compound in the edge polishing composition gives to the edge of the substrate The edge of the substrate is polished.

  The edge polishing composition of this embodiment can be used in the same apparatus and conditions that are normally used in the polishing step of a general substrate manufacturing method.

  As the load applied to the edge of the substrate by the polishing pad, that is, the polishing load is increased, the polishing rate is increased. The polishing load when polishing the edge of the substrate using the edge polishing composition of the present embodiment is not particularly limited, but in order to obtain a practically sufficient polishing rate, it may be 6 kgf (about 59 N) or more. More preferably, it is 9 kgf (about 88 N) or more. In order to obtain a substrate that is not damaged after polishing, the polishing load is preferably 16 kgf (about 157 N) or less, more preferably 12 kgf (about 118 N) or less.

  As the number of rotations of the polishing pad is increased, the frictional force applied to the edge of the substrate is increased, so that the edge of the substrate is more strongly subjected to mechanical polishing. Further, since the frictional heat is increased, the etching action by the basic compound is increased. As a result, the edge of the substrate is more strongly subjected to the chemical polishing action. The number of rotations of the polishing pad when polishing the edge of the substrate using the edge polishing composition of the present embodiment is not particularly limited, but is preferably 400 rpm or more in order to obtain a practically sufficient polishing rate. More preferably, it is 600 rpm or more. In order to obtain a substrate that is not damaged after polishing, the number of revolutions of the polishing pad is preferably 1,000 rpm or less, and more preferably 800 rpm or less.

  When polishing the edge of the substrate using the edge polishing composition of the embodiment, any type of polishing pad such as a nonwoven fabric type or a suede type may be used. The polishing pad to be used may contain abrasive grains or may not contain abrasive grains.

  The edge polishing composition may be used in a so-called pouring that is discarded once used for polishing the edge of the substrate. Alternatively, the edge polishing composition used for polishing the edge of the substrate may be recovered and reused (circulated). More specifically, the used polishing composition discharged from the polishing apparatus may be once collected in a tank and supplied from the tank to the polishing apparatus again. In this case, since it is not necessary to treat the used polishing composition as a waste liquid, it is possible to reduce the environmental load and the cost.

  When the edge polishing composition is used in a circulating manner, the decrease in at least one of the constituent components in the polishing composition consumed or lost by being used for polishing the edge of the substrate is replenished. You may make it perform.

  When the edge polishing composition is used in a circulating manner, a pH adjuster is appropriately supplemented to adjust the pH of the edge polishing composition within a predetermined range, preferably 9.0 to 13.0, more preferably. You may make it keep in the range of 9.5-11.4.

  The edge polishing composition of the embodiment may be a one-part type or a multi-part type including a two-part type. For example, the edge polishing composition may be prepared by mixing at least a first agent and a second agent. The first agent contains at least one of a synthetic water-soluble polymer and a basic compound having a heterocyclic ring in the side chain or terminal and water, and the second agent is a synthesis having a heterocyclic ring in the side chain or terminal. You may contain at least the other of water-soluble polymer and a basic compound, and water. More specifically, the edge polishing composition contains at least a first agent containing at least a synthetic water-soluble polymer having a heterocyclic ring at the side chain or terminal, a basic compound and water, and abrasive grains and water. You may prepare by mixing a 2nd agent. In this case, the abrasive grains can be stored in a stable state in the second agent. Alternatively, edge polishing is performed by mixing a first agent containing at least a basic compound, abrasive grains, and water with a second agent containing at least a synthetic water-soluble polymer having a heterocyclic ring at the side chain or terminal and water. A composition for use may be prepared. In this case, the synthetic water-soluble polymer can be stored in the second agent in a state where decomposition is suppressed. The edge polishing composition may be prepared by separately supplying the first agent and the second agent to the same polishing apparatus and mixing the first agent and the second agent in the polishing apparatus.

  The edge polishing composition of the embodiment may be in a concentrated state at the time of production and sales. That is, the edge polishing composition of the above embodiment may be manufactured and sold in the form of a stock solution having a lower water content than the edge polishing composition. In this case, the edge polishing composition is prepared by diluting the stock solution with water. Since water used for dilution is generally available everywhere, transportation and storage costs can be reduced by transporting and storing in the form of a stock solution having a small volume.

  The concentration ratio of the stock solution is not particularly limited, but is preferably 2 times or more, more preferably 10 times or more, and further preferably 20 times or more. As used herein, the concentration ratio refers to the ratio of the total volume of the edge polishing composition prepared by diluting water from the stock solution to the total volume of the stock solution.

  The content of the synthetic water-soluble polymer having a heterocyclic ring at the side chain or terminal in the stock solution of the edge polishing composition is preferably 0.002% by mass or more, more preferably 0.004% by mass or more. More preferably, it is 0.006 mass% or more. Moreover, this content is preferably 0.02% by mass or less, more preferably 0.015% by mass or less. In this case, an edge polishing composition containing the synthetic water-soluble polymer at an appropriate concentration can be obtained by diluting the stock solution with water at a predetermined dilution rate.

  The edge polishing composition of the above embodiment may be stored at room temperature for 24 hours or more after preparation by diluting the stock solution. In the case of an edge polishing composition having excellent stability, it is possible to maintain certain polishing conditions by using it over a long period of time. In general, however, the storage after preparation is preferably within 24 hours at room temperature.

  Next, examples and comparative examples of the present invention will be described.

Examples 1 to 23, in which a part or all of a synthetic water-soluble polymer having a heterocyclic ring at the side chain or terminal or an alternative substance, a basic compound, an abrasive, a chelating agent, and a wetting agent are mixed with ion-exchanged water . The edge polishing compositions of 25, 27, 28, Reference Examples 24, 26, 29 , 30 and Comparative Examples 1 to 26 were prepared. Table 1 shows details of components in each of the edge polishing compositions of Examples 1 to 23, 25, 27, 28, Reference Examples 24, 26, 29 , 30 and Comparative Examples 1 to 26. In Table 1, the “average molecular weight” column in the “synthetic water-soluble polymer having a heterocyclic ring at the side chain or terminal or a substance replacing it” column shows the value of the weight average molecular weight in terms of polyoxyethylene.

A silicon wafer having a conductivity type of P-type, a crystal orientation of <100>, a resistivity of 0.1 Ω · cm to less than 100 Ω · cm, and a size of 3 cm in length × 1 cm in width , 28, immersion in each edge polishing composition of Reference Examples 24, 26, 29 , 30 and Comparative Examples 1 to 26 at room temperature for 24 hours, and whether or not the surface of the silicon wafer after immersion is rough is visually observed. Examined. In the “Evaluation” column of Table 1, the “Surface roughness” column shows “A” when no roughness was observed, “B” when almost no roughness was observed, and those with roughness observed. The result of evaluation as “C” is shown.

Using the edge polishing compositions of Examples 1 to 23, 25, 27, 28, Reference Examples 24, 26, 29 , 30 and Comparative Examples 1 to 26, the surface of the silicon wafer was subjected to the conditions described in Table 2. Polished. The silicon wafer used had a diameter of 300 mm, a conductivity type of P type, a crystal orientation of <100>, and a resistivity of 0.1 Ω · cm to less than 100 Ω · cm. At this time, the polishing rate was determined by dividing the difference in mass of the silicon wafer measured before and after polishing by the polishing time. In the “Polishing Rate” column in the “Evaluation” column of Table 1, “A” when the polishing rate is 5.0 mg / min or more, “B” when it is 4.5 mg / min or more; In the case of 2 mg / min or more, the evaluation result is “C”, in the case of 3.8 mg / min or more, “D”, and in the case of less than 3.8 mg / min, the evaluation result is “E”.

As shown in Table 1, the edge polishing compositions of Examples 1 to 23, 25, 27, and 28 and Reference Examples 24, 26, 29, and 30 passed with an evaluation of surface roughness of “A” or “B”. The evaluation of the polishing rate was also “A” to “D”, which was also acceptable. On the other hand, the compositions for edge polishing of Comparative Examples 1 to 26 were “C” in which the evaluation of surface roughness was not an acceptable level, or “E” in which the evaluation of the polishing rate was not at an acceptable level.

Although no particular data is shown, 20-fold concentrated solutions of the edge polishing compositions of Examples 1 to 23, 25, 27, 28, Reference Examples 24, 26, 29 , 30 and Comparative Examples 1 to 26 were prepared. And after storing this at room temperature for 6 months, diluted solutions obtained by diluting 20 times with ion-exchanged water were found in Examples 1 to 23, 25, 27, 28, Reference Examples 24, 26, 29 , 30 and The edge polishing compositions of Comparative Examples 1 to 26 had the same performance.

Claims (10)

0.0001% by mass or more of a synthetic water-soluble polymer having a heterocyclic ring at the side chain or terminal (excluding an average molecular weight of 3000 or less)
At least one selected from imidazole and imidazole derivatives as basic compounds;
An edge polishing composition containing water. The edge polishing composition according to claim 1, wherein the synthetic water-soluble polymer has an average molecular weight of 5000 or less .   The edge polishing composition according to claim 1, wherein the heterocyclic ring is a lactam ring or a tetrahydrofuran ring.   The synthetic water-soluble polymer according to any one of claims 1 to 3, wherein the synthetic water-soluble polymer is at least one selected from polyvinyl pyrrolidone, polyvinyl caprolactam, polyoxyethylene sorbitan monolaurate, and polyoxyethylene sorbitan trioleate. Edge polishing composition.   The edge polishing composition according to any one of claims 1 to 4, further comprising abrasive grains.   Furthermore, the composition for edge grinding | polishing as described in any one of Claims 1-5 containing a chelating agent.   The edge polishing composition according to any one of claims 1 to 6, further comprising a wetting agent. The composition for edge polishing according to any one of claims 1 to 7, wherein the synthetic water-soluble polymer is contained in an amount of 0.0002% by mass or more. The method of grind | polishing the edge of a board | substrate using the composition for edge polishing as described in any one of Claims 1-8 . A method for manufacturing a substrate, comprising a step of polishing an edge of the substrate using the method according to claim 9 .