TW201400598A - Polish composition, method of manufacturing the same, and method of manufacturing substrate - Google Patents

Abstract

The present invention relates to a polish composition, including: an oxidation agent (A); one or more acids (B) which are selected from among an amino acid, a carboxylic acid in which the number of carbon atoms other than a carboxylic group is less than 8, and an inorganic acid; a sulfonic acid (C) having an alkyl group in which the concentration is greater than 0.01% by mass and which has an alkyl group having 8 or more and 15 or less carbon atoms; a fatty acid (D) having an alkyl group in which the concentration is greater than 0.001% by mass and which has an alkyl group having 8 or more and 15 or less carbon atoms; a non-ionic water-soluble polymer (E); an abrasive (F) which is coated with the non-ionic water-soluble polymer; and water (G) as a dispersion media, wherein pH is 7 to 11, and 1 to 10 parts by mass of the non-ionic water-soluble polymer is contained to 100 parts by mass of the abrasive.

Description

Polishing composition, manufacturing method of polishing composition, and method of manufacturing substrate

The present invention relates to a polishing composition, a method for producing a polishing composition, and a method for producing a substrate using the polishing composition.

The present application claims priority based on Japanese Patent Application No. 2012-86440, filed on Apr. 5, 2012, in Japan, and Japanese Patent Application No. 2013-. .

High-integration and high-performance semiconductor devices such as integrated circuit (IC: Integrated Circuit), large-scale integrated circuit (LSI: Large Scale Integration), and magnetic random access memory (MRAM) Gradually developed. In such a manufacturing technology of a semiconductor device, a new microfabrication technology has been developed. One of the microfabrication techniques is CMP (Chemical Mechanical Polishing, hereinafter referred to as CMP). The chemical mechanical polishing method frequently uses a step of forming a metal wiring, a step of flattening an insulating film, and the like in the production of such a semiconductor device.

Further, recently, in order to solve the problem of wiring delay, attempts have been made to use wiring composed of copper or a copper alloy. A wiring composed of copper or a copper alloy is formed by a damascene method. In the damascene method, a film of copper or a copper alloy is deposited on an insulating film in which a trench is formed in advance, and a film of copper or a copper alloy is buried in the trench, and then removed by a CMP method to form a trench. The film on the insulating film leaves a copper or copper alloy in the trench as a method of wiring. A wiring made of copper or a copper alloy buried in a trench on the insulating film can be formed by a damascene method.

A CMP method suitable for the damascene method is known as a method of using various polishing compositions. Patent Document 1 discloses a polishing composition containing a positively charged polymer electrolyte and abrasive particles electrostatically bonded to the polymer electrolyte. Patent Document 2 discloses a polishing composition containing an abrasive particle and a polymer electrolyte having an ionic charge different from the abrasive particles.

However, in Patent Document 1, the aggregation stability of the abrasive particles is disclosed, but the performance such as the polishing rate or the flatness is not clearly disclosed. The CMP method described in Patent Document 2 is a mechanism in which a polymer electrolyte is adsorbed to a part of the abrasive particles to cause a difference between a polishing rate of the object to be polished and a polishing rate of the concave portion. In the technique described in Patent Document 2, the dispersibility of the abrasive particles (abrasive grains) is insufficient. Therefore, there is a problem that it is difficult to control the polishing rate.

Further, as shown in Patent Document 3, a water-soluble nonionic polymer is used in a CMP method using a polishing composition containing a water-soluble nonionic polymer and abrasive grains bonded to a water-soluble nonionic polymer. Will attach An insulating film such as an oxide film. Therefore, there is a problem that the polishing rate of the insulating film is lowered. In addition, the polishing rate refers to the amount of grinding per unit time.

On the other hand, in the damascene method, in order to prevent the wiring material from diffusing toward the insulating film, a wiring made of copper or a copper alloy may be buried in the trench after the barrier metal film is formed in the trench of the insulating film. material. In the CMP method, the polishing rate of the insulating film is liable to lower, and on the other hand, the polishing rate of the barrier metal film is not easily lowered. Therefore, in the semiconductor device, the portion where the wiring is arranged at a high density is subjected to the CMP method, and if the wiring is blocked together, the metal film is preferentially polished, and as a result, the insulating film located around the barrier metal film is excessively excessively Grinding situation. Such a phenomenon is generally called erosion. In particular, when the wiring width is reduced as the semiconductor device is integrated, the etching is likely to occur. Erosion may cause the wiring resistance to increase, or cause the wiring to be short-circuited to each other. Therefore, it is desirable to prevent erosion.

As described above, in the conventional CMP method, it is difficult to control the polishing rate of the barrier metal film, and it is impossible to prevent the etching of the insulating film. Therefore, it is difficult to manufacture a substrate which is excellent in flatness.

[Previous Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent No. 4750362

[Patent Document 2] Japanese Patent No. 3130279

[Patent Document 3] US Patent No. 6331134

An object of the present invention is to provide a polishing composition capable of suppressing the polishing rate of a barrier metal film and preventing erosion of an insulating film, a method for producing the polishing composition, and a method for producing a substrate using the polishing composition.

In order to achieve the above object, the present invention provides the following means.

[1] A polishing composition comprising: (A) an oxidizing agent; (B) one or more selected from the group consisting of a carboxylic acid or a mineral acid having an amino acid other than a carboxyl group and having a carbon number of less than eight (C) a sulfonic acid having a concentration of 0.01% by mass or more and having an alkyl group having 8 or more and 15 or less carbon atoms; (D) an alkane having a concentration of 0.001% by mass or more and having 8 or more and 15 or less carbon atoms; a fatty acid; (E) a nonionic water-soluble polymer; (F) an abrasive particle coated with the aforementioned nonionic water-soluble polymer; and (G) a water as a dispersion medium, having a pH of 7 to 11, and The nonionic water-soluble polymer is contained in an amount of 1 to 10 parts by mass based on 100 parts by mass of the abrasive grains.

[2] The polishing composition according to [1], wherein the nonionic water-soluble polymer is polyvinylpyrrolidone.

[3] The polishing composition according to [1] or [2] wherein the oxidizing agent is a persulfate.

[4] The polishing composition according to any one of [1] to [3] wherein the concentration of the oxidizing agent is 0.01 to 30% by mass based on the polishing composition.

[5] The polishing composition according to any one of [1] to [4] wherein the carboxylic acid is oxalic acid and/or hexanoic acid.

[6] The polishing composition according to any one of [1] to [5] wherein the sulfonic acid-based alkylbenzenesulfonic acid.

[7] The polishing composition according to any one of [1] to [6] wherein the fatty acid is octanoic acid.

[8] The polishing composition according to any one of [1] to [7] wherein the concentration of the abrasive grains is 0.01 to 10% by mass based on the polishing composition.

[9] The polishing composition according to any one of [1] to [8] wherein the abrasive particles are colloidal cerium oxide.

[10] The polishing composition according to any one of [1] to [9] further comprising benzotriazole, tolyltriazole, hydroxybenzotriazole, carboxybenzotriazole, benzimidazole, At least one or two or more selected from the group consisting of tetrazole, 2-quinolinecarboxylic acid, and vinylimidazole, and the concentration thereof is 0.5% by mass or less.

[11] The polishing composition according to any one of [1] to [10] which is used for polishing a metal film and/or a barrier metal film of a concave portion of an insulating film formed on a substrate.

[12] A method for producing a polishing composition, which is one or more selected from the group consisting of (A) an oxidizing agent, (B) an amino acid, a carboxylic acid having a carbon number of less than 8, or a mineral acid. a sulfonic acid having a concentration of (C) of 0.01% by mass or more and having an alkyl group having 8 or more and 15 or less carbon atoms, (D) The fatty acid having a concentration of 0.001% by mass or more and having an alkyl group having 8 or more and 15 or less carbon atoms, (F') abrasive grains, and (E') are 1 to 10 parts by mass based on 100 parts by mass of the abrasive grains. The ionic water-soluble polymer is mixed in water as a dispersion medium, the pH is adjusted to 7 to 11, and the abrasive grains are coated with the nonionic water-soluble polymer.

[13] A method for producing a polishing composition, comprising the steps of: mixing a nonionic water-soluble polymer in an amount of 1 to 10 parts by mass based on 100 parts by mass of the abrasive grains, and dissolving the nonionic water in the foregoing manner; a pretreatment step of coating the aforementioned abrasive particles with a polymer, and one or two selected from the group consisting of (A) an oxidizing agent, (B) an amino acid, a carboxylic acid having a carbon number of less than 8, or a mineral acid. The above-mentioned acid and the (C) concentration are 0.01% by mass or more, and the sulfonic acid having 8 or more and 15 or less carbon atoms, (D) has a concentration of 0.001% by mass or more, and has a carbon number of 8 or more and 15 or less. The alkyl fatty acid and (F) the abrasive particles coated with the nonionic water-soluble polymer are mixed in water as a dispersion medium to adjust the pH to 7 to 11.

[14] A method for producing a substrate, which is a metal film or a barrier metal film formed in a concave portion of an insulating film provided on a substrate by the polishing composition according to any one of [1] to [11] Either or both.

[15] The method for producing a substrate according to [14], wherein the metal film is copper or an alloy containing copper.

[16] The method for producing a substrate according to [14], wherein the barrier metal film is a tantalum or a tantalum alloy.

According to the polishing composition of the present invention, since the abrasive particles coated with the nonionic water-soluble polymer are sufficiently dispersed in the solvent, the polishing rate of the metal film or the barrier metal film as the wiring material can be suppressed.

Further, according to the polishing composition of the present invention and the method for producing a substrate using the polishing composition, since the adsorption of the nonionic water-soluble polymer to the insulating film can be prevented, the polishing rate of the insulating film is not lowered. Therefore, even in the case of a substrate having an insulating film in which fine wiring is disposed at a high density, the etching of the insulating film during CMP processing can be suppressed, and the flatness of the substrate can be maintained at a high level.

1‧‧‧Insulation film

2‧‧‧ trench

2'‧‧‧ wiring

3‧‧‧ Space

4‧‧‧Barrier metal film

5‧‧‧Metal film

[Fig. 1] Fig. 1 is a schematic cross-sectional view showing the formation of wiring by a damascene method.

[Fig. 2] Fig. 2 is a schematic cross-sectional view showing the depression.

[Fig. 3] Fig. 3 is a schematic cross-sectional view showing erosion.

Hereinafter, the polishing composition of the present invention as a preferred embodiment will be described in detail. In addition, the materials and dimensions exemplified in the following description are merely examples, and the present invention is not limited thereto. Further, the present invention can be carried out by appropriately changing the scope of the invention without departing from the spirit and scope of the invention.

A polishing composition according to a preferred embodiment of the present invention is a metal film and/or a barrier metal film which is formed by polishing a concave portion of an insulating film formed on a substrate. The polishing composition has: (A) an oxidizing agent, (B) an acid, (C) a sulfonic acid, (D) a fatty acid, (E) a nonionic water-soluble polymer, and (F) a water-soluble polymerization by the aforementioned nonionic Object coated abrasive particles. Further, in the polishing composition of the preferred embodiment of the present invention, the components (A) to (F) are added to the (G) dispersion medium. Hereinafter, the details of each component will be described.

<(A) Oxidizer>

The oxidizing agent contained in the polishing composition of the present embodiment is preferably one which oxidizes the metal film or the barrier metal film by imparting oxygen. More specifically, oxygen, ozone, hydrogen peroxide, alkyl peroxide, peroxyacid, permanganate, periodate, persulfate, hypochlorite, polyoxoacid can be used. )Wait. The alkyl peroxide system is exemplified by t-butyl hydroperoxide or ethylbenzene hydroperoxide. The peroxyacid system can be exemplified by peracetic acid, perbenzoic acid, and the like. The permanganate system can be exemplified by potassium permanganate or the like. The periodate group can be exemplified by potassium periodate or the like. The persulfate system can be exemplified by ammonium persulfate or potassium persulfate. The hypochlorite system can be exemplified by potassium hypochlorite or the like. By using such an oxidizing agent, a metal film or a barrier metal film composed of a metal or a metal alloy can be oxidized to increase the polishing rate of the metal film or the barrier metal film. In addition, among such oxidizing agents, it is particularly preferable to use persulfate. It is easy to treat by persulfate as an oxidizing agent.

In addition, the concentration of the oxidant relative to the polishing composition It is preferably 0.01 to 30% by mass, more preferably 0.05 to 20% by mass, still more preferably 0.1 to 10% by mass. By the concentration of the oxidizing agent being 0.01 to 30% by mass based on the polishing composition, a sufficient polishing rate for a metal film or a barrier metal film can be obtained. When the concentration of the oxidizing agent is 0.01% by mass or more based on the polishing composition, the polishing rate for the metal film becomes sufficient. In addition, as long as the concentration of the oxidizing agent is 30% by mass or less based on the polishing composition, a dense oxide film is not formed on the surface of the metal film by the excessive oxidizing agent, and the polishing rate for the metal film is not suppressed, which is preferable.

<(B)acid>

In the present embodiment, one or two or more selected from the group consisting of a carboxylic acid or a mineral acid having a carbon number of less than eight, other than a carboxyl group, are used.

Specifically, amino acid can be used: glycine, alanine, β-alanine, 2-aminobutyric acid, n-proline, valine, leucine, orthra-acid, Aleucine, iso- lysine, phenylalanine, valine, creatinine, ornithine, lycine, taurine, serine, threonine, besulamide, Serine, tyrosine, 3,5-iodo-tyrosine, β-(3,4-dihydroxyphenyl)-alanine, thyroxine, 4-hydroxy-proline, cysteine ,methionine, ethionine, lanthionine, cystathionine, cystine, oxidized cysteine, aspartic acid, glutamic acid, S-(carboxymethyl)-cysteamine Acid, 4-aminobutyric acid, aspartic acid, glutamic acid, nitrogen serine, arginine, concanavalin, citrulline, δ-hydroxy-betaine, creatine, canine Amino acid, histidine, 1-methyl-histamine Acid, 3-methyl-histamine, ergothiol, tryptophan, and the like.

Further, the carboxylic acid having less than 8 carbon atoms other than the carboxyl group does not contain an amino acid. Examples of the carboxylic acid may be, for example, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid. , 4-methylpentanoic acid, n-heptanoic acid, 2-methylhexanoic acid, n-octanoic acid, 2-ethylhexanoic acid, benzoic acid, glycolic acid, salicylic acid, glyceric acid, oxalic acid, malonic acid, amber A carboxylic acid such as acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, malic acid, tartaric acid, citric acid, lactic acid, or the like, and salts thereof. The carboxylic acid system is particularly preferably used with oxalic acid and/or hexanoic acid. The oxalic acid and/or caproic acid is preferred because it has a high polishing rate for the metal film and can form a substrate having higher flatness.

Further, as the inorganic acid, for example, sulfuric acid, phosphoric acid, phosphonic acid, nitric acid or the like can be used.

The acid system may be used alone or in combination of two or more. Further, the concentration of the acid is preferably 0.01 to 10% by mass, more preferably 0.02 to 5% by mass, still more preferably 0.05 to 2% by mass based on the polishing composition. By setting the acid concentration to 0.01 to 10% by mass based on the polishing composition, a practical polishing rate for the metal film can be obtained. When the concentration of the acid is 0.01% by mass or more based on the polishing composition, the polishing rate for the metal film becomes sufficient. In addition, as long as the concentration of the acid is 10% by mass or less based on the polishing composition, the etching speed of the metal film or the barrier metal film composed of the metal or the metal alloy does not become too high, and the corrosion of the wiring surface can be prevented. Or a decrease in flatness.

<(C)sulfonic acid>

In the present embodiment, those having a carbon number of 8 or more and 15 or less are used as the sulfonic acid. The sulfonic acid group having an alkyl group may, for example, be an alkylsulfonic acid or an alkylaromatic sulfonic acid.

The alkylsulfonic acid system is exemplified by mercaptosulfonic acid, dodecylsulfonic acid and the like.

The alkyl aromatic sulfonic acid may, for example, be an alkyl benzenesulfonic acid, an alkylnaphthalenesulfonic acid or an alkyl sulfonic acid formaldehyde condensate.

The sulfonic acid system is particularly preferably an alkylbenzenesulfonic acid. The alkylbenzenesulfonic acid system can be exemplified by mercaptobenzenesulfonic acid, undecylbenzenesulfonic acid, dodecylbenzenesulfonic acid, tridecylbenzenesulfonic acid, tetradecylbenzenesulfonic acid, or the like. a mixture.

Further, salts such as potassium salts or ammonium salts of such sulfonic acids can also be used.

Further, not only one type of sulfonic acid but also two or more types may be used in combination. By using a sulfonic acid, the occurrence of a step difference or a corrosion of a metal portion of the metal portion and the insulating film composed of the metal film and/or the barrier metal film can be sufficiently suppressed.

Further, the concentration of the sulfonic acid in the present embodiment is preferably 0.01% by mass or more based on the polishing composition, more preferably 0.01 to 5% by mass, even more preferably 0.05 to 1% by mass, and 0.05%. 0.5% by mass is particularly good. By setting the concentration of the sulfonic acid to 0.01% by mass or more based on the polishing composition, it is possible to prevent the occurrence of a step difference or flatness of the metal portion and the insulating film. When the concentration of the sulfonic acid is 5% by mass or less based on the polishing composition, it is preferred that the polishing rate of the metal film is not suppressed.

<(D) fatty acid>

In the present embodiment, those having a carbon number of 8 or more and 15 or less are used as the fatty acid. The fatty acid having an alkyl group may, for example, be a saturated fatty acid or an unsaturated fatty acid. Further, a salt such as a potassium salt or an ammonium salt of a fatty acid can also be used. The saturated fatty acid is preferably octanoic acid, caprylic acid, citric acid, citric acid, lauric acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, icosonic acid, twenty-two Acid, tetracosic acid, hexacylic acid, octadecanoic acid, tridecanoic acid, and the like.

Further, as the unsaturated fatty acid, it is preferred to use eicosapentaenoic acid, oleic acid, linoleic acid, uric acid or the like.

Among these, fatty acids are particularly preferred as octanoic acid.

In addition, one type of the fatty acid may be used in combination, and two or more types may be used in combination. By using a fatty acid, the occurrence of a step difference between the metal portion and the insulating film or the corrosion of the metal portion can be sufficiently suppressed.

Further, the concentration of the fatty acid in the present embodiment is preferably 0.001% by mass or more based on the polishing composition, more preferably 0.001 to 5% by mass, still more preferably 0.005 to 1% by mass, and even more preferably 0.05 to 0.5% by weight. The quality is very good. By setting the concentration of the fatty acid to 0.001% by mass or more based on the polishing composition, it is possible to prevent the occurrence of a step difference between the metal portion and the oxide film or the deterioration of the flatness of the surface of the substrate on which the wiring is provided. In addition, by setting the concentration of the fatty acid to 5% by mass or less based on the polishing composition, corrosion of the metal portion can be sufficiently suppressed.

<(E) Nonionic Water Soluble Polymer>

A nonionic water-soluble polymer is added to the polishing composition of the present embodiment. The nonionic water-soluble polymer is coated with the abrasive grains described later by hydrogen bonding or van der Waals force. As such a nonionic water-soluble polymer, polyvinylpyrrolidone, hydroxypropylmethylcellulose, polyvinyl alcohol, vinylpyrrolidone (co)polymer, propylene morpholine (co)polymer, N-isopropyl acrylamide (co)polymer or the like. Among them, polyvinylpyrrolidone is particularly preferred. The non-ionic water-soluble polymer may be used alone or in combination of two or more.

By using a nonionic water-soluble polymer to sufficiently adsorb the nonionic water-soluble polymer to the abrasive grains, it contributes to the dispersion stability of the abrasive grains. Further, the adsorption of the nonionic water-soluble polymer and the abrasive particles is caused by hydrogen bonding or van der Waals, and is irreversible. Therefore, the nonionic water-soluble polymer does not separate once adsorbed on the abrasive particles, and does not dissociate in the dispersion medium. These effects are particularly excellent in polyvinylpyrrolidone. Further, since the polyvinylpyrrolidone has a guanamine bond, it can be stably left without being dissociated from the abrasive grains under the conditions of neutral to weakly basic in the dispersion medium suitable for the polishing composition of the present invention.

The nonionic water-soluble polymer is preferably a weight average molecular weight of 3,000 to 1,500,000, and particularly preferably 3,000 to 1,000,000. By using such a condition as a nonionic water-soluble polymer, it is possible to sufficiently suppress fine corrosion of the surface of the metal portion.

Further, the nonionic water-soluble polymer is preferably one which is soluble in 5% by mass or more in water at 25 °C.

The nonionic water-soluble polymer may also be one having a specific functional group. Such a functional group is preferably an alcoholic hydroxyl group, a cyclic decylamine or an N-alkyl substituted guanamine group. The alcoholic hydroxyl group may also be introduced by a polymer reaction. The nonionic water-soluble polymer having an alcoholic hydroxyl group may, for example, be a polyvinyl alcohol obtained by saponification of a vinyl acetate polymer.

The nonionic water-soluble polymer of the present embodiment may be, for example, a polymer having a nonionic hydrophilic group and a polymer or copolymer having a monomer having a vinyl group, or a homopolymer of either of them. . The single system having a nonionic hydrophilic group or a vinyl group may, for example, be acrylamide, N-vinylacetamide, dimethyl acrylamide, N-isopropyl acrylamide, vinyl pyrrolidone, Vinyl caprolactam, propylene morpholine, diacetone acrylamide, and the like.

The nonionic water-soluble polymer may be a copolymer of a monomer having a nonionic hydrophilic group and a monomer having hydrophobicity. Examples of the single system having hydrophobicity include styrene, N-t-octylacrylamide, and the like.

The amount of the nonionic water-soluble polymer to be used in the present embodiment is preferably 1 to 10 parts by mass, more preferably 2 to 9 parts by mass, even more preferably 3 to 7 parts by mass based on 100 parts by mass of the abrasive grains described later. Parts by mass. By using the amount of the nonionic water-soluble polymer in this range, about 100% of the nonionic water-soluble polymer is applied to the abrasive grains. Thereby, the adsorption of the nonionic water-soluble polymer to the insulating film is prevented without lowering the polishing rate of the insulating film. When the concentration of the nonionic water-soluble polymer is 1 part by mass or more with respect to 100 parts by mass of the abrasive grains, it is possible to The abrasive particles are sufficiently coated with an ionic water-soluble polymer. In addition, as long as the nonionic water-soluble polymer is used in an amount of 10 parts by mass or less based on 100 parts by mass of the abrasive grains, the remaining nonionic water-soluble polymer is not adsorbed on the insulating film to polish the insulating film. The rate is reduced. In addition, the addition of the excess nonionic water-soluble polymer promotes the aggregation of the abrasive particles to lower the stability of the polishing composition, so that the amount of the nonionic water-soluble polymer is made with respect to 100 parts by mass of the abrasive grains. 10 parts by mass or less can be used.

<(F) abrasive grain>

In the present embodiment, colloidal cerium oxide, cerium oxide, aluminum oxide, cerium oxide, an organic polishing material or the like can be used as the abrasive grain system. In addition, not only one of these types of abrasive grains but also two or more types may be used in combination. In particular, the abrasive granules are preferably sized colloidal cerium oxide. By using the above as the abrasive grains, scratches on the surface of the substrate can be prevented from occurring.

The content of the abrasive grains is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, particularly preferably 0.1 to 1% by mass, based on the polishing composition. When the content of the abrasive grains is within this range, the occurrence of a step between the metal portion and the insulating film or the occurrence of scratches can be sufficiently prevented. On the other hand, as long as the content of the abrasive grains is 0.01% by mass or more, the polishing rate of the metal film becomes sufficient. In addition, as long as the content of the abrasive grains is 10% by mass or less, the occurrence of a step difference between the metal portion and the oxide film or the occurrence of scratches can be sufficiently suppressed.

The abrasive granules in this embodiment are made of nonionic water. The polymer is coated and coated around it. Therefore, the abrasive grains are sufficiently dispersed in the dispersion medium, and the polishing rate of the wiring can be suppressed.

The average particle diameter of the abrasive grains is preferably 1 μm or less, more preferably 0.01 μm to 0.5 μm, still more preferably 0.02 μm to 0.25 μm. By the average particle diameter of the abrasive grains being 1 μm or less, the polishing rate can be sufficiently maintained, and the occurrence of scratches or the like can be prevented. In particular, as long as the average particle diameter of the abrasive grains is 0.01 μm or more, the polishing rate for the metal film becomes sufficient. Further, as long as the average particle diameter of the abrasive grains is 0.5 μm or less, the occurrence of scratches can be prevented. The average particle diameter of the abrasive grains can be obtained by using a volume average particle diameter D ₅₀ measured by a dynamic light scattering type particle size distribution measuring machine (for example, UPA150 manufactured by MICROTRACK).

The pH (hydrogen ion index) of the polishing composition in the present embodiment is preferably in the range of 7 to 11, more preferably 8 to 10, still more preferably 8.5 to 10. The measured value of pH can also be measured using, for example, a pH meter (PH71) manufactured by YOKOGAWA at 25 °C.

By setting the pH of the polishing composition to 7 to 10, the nonionic water-soluble polymer is made cationic, and dissociation from the coated abrasive particles can be prevented. As the reagent for adjusting the pH of the polishing composition, a mineral acid, an organic acid, a base or the like can be suitably used.

The polishing composition of the present embodiment may further contain benzotriazole, tolyltriazole, hydroxybenzotriazole, carboxybenzotriazole, benzimidazole, tetrazole or 2-quinolinecarboxylic acid ( One or more selected from the group consisting of quinaldic acid) and vinyl imidazole. The concentration in the polishing composition is preferably 0.001 to 0.5% by mass based on the polishing composition. By The concentration of 0.001 to 0.5% by mass of the polishing composition is contained, and corrosion of the surface of the wiring (metal film or barrier metal film) can be suppressed, and the polishing rate of the wiring surface can be appropriately suppressed. The concentration in the polishing composition is preferably from 0.002 to 0.02% by mass based on the polishing composition.

<(G) Dispersion Medium>

The dispersion medium for the polishing composition is preferably water, and it is preferred to use high-purity water such as distilled water or ion-exchanged water.

Next, a method for producing a polishing composition according to a preferred embodiment of the present invention will be described.

The polishing composition of the present invention as a preferred embodiment is obtained by using the above (A) oxidizing agent, (B) acid, (C) sulfonic acid, (D) fatty acid, (E) nonionic water-soluble polymer. And (F) the abrasive grains are mixed in the (G) dispersion medium, the pH is adjusted to 7 to 11, and the abrasive grains are coated with a nonionic water-soluble polymer.

In order to apply the nonionic water-soluble polymer to the surface of the abrasive grains for coating, pretreatment may also be carried out. First, the abrasive grains are mixed with water, and the nonionic water-soluble polymer is mixed while stirring. The stirring system can be carried out using, for example, a stirrer, a homogenizer, an ultrasonic disperser or the like. When a stirrer was used, the stirring fan blade was rotated at 10 to 100 rpm, and the mixture was stirred for 1 hour at 100 to 1000 rpm for 30 minutes or longer. Thereby, the nonionic water-soluble polymer is adsorbed to the surface of the abrasive grain having a plurality of negative charges to obtain an abrasive particle coated with the nonionic water-soluble polymer.

In the polishing composition of the preferred embodiment of the present invention, the abrasive particles are sufficiently dispersed in the solvent by coating the surface of the abrasive grains with a nonionic water-soluble polymer. Therefore, the polishing rate of the wiring (metal film and/or barrier metal film) can be suppressed. Further, since it contains 1 to 10 parts by mass of the nonionic water-soluble polymer with respect to 100 parts by mass of the abrasive grains, the nonionic water-soluble polymer is adsorbed to the abrasive grains in about 100%, and is hardly released in the dispersion medium. . Therefore, the nonionic water-soluble polymer does not adsorb to the insulating film as the object to be polished, and the polishing rate of the insulating film can be prevented from being lowered. By this means, even if the thin wiring made of the metal film is densely embedded in the substrate of the insulating film, the etching of the wiring and the insulating film can be suppressed, and the substrate can be polished while maintaining high flatness. Thus, a substrate which is free from depression and which is excellent in flatness can be manufactured.

Further, in the polishing composition of the preferred embodiment of the present invention, the non-ionic water-soluble polymer in the solvent is almost coated with the abrasive particles, which is different from the conventional polishing composition, but the above effects are obtained. Performance other than that is not easy to change. Therefore, in addition to the effects of the conventional polishing composition, the effects of the present invention can be obtained, and it is very easy for the user.

Next, a method of manufacturing a substrate using the polishing composition of the present invention as a preferred embodiment will be described. The polishing composition of the present invention is used, for example, in a manufacturing process of a semiconductor device, in which a metal film or a metal film as a wiring material and a barrier metal film are buried in a trench of an insulating film on a substrate, and then the metal film and When the barrier metal film is polished and buried in the insulating film to form wiring.

Using the abrasive composition of the present invention as a preferred embodiment The method for producing a substrate is roughly configured by a step of preparing a polishing target having a polishing composition, a metal film or a barrier metal film, and a polishing apparatus, and a step of polishing the metal film or blocking the metal film. Hereinafter, the details of each component will be described.

(Steps of preparing a polishing composition, an object to be polished, and a polishing apparatus)

First, the polishing composition of the preferred embodiment of the present invention will be described. The polishing composition of the present invention can be adjusted not only from the initial use to the use liquid, but also in consideration of the stability of the liquid, etc., and the convenience of the treatment, and the components which are divided into a plurality of components according to each component are mixed and stored before being used. As a polishing composition. Further, the polishing composition may be stored in a state of a concentrated liquid, and the preservation solution may be diluted as a polishing composition at the time of use.

In the present invention, before the grinding step, as long as at least the abrasive particles are previously mixed with the nonionic water-soluble polymer, and the abrasive particles are coated with the nonionic water-soluble polymer, the polishing composition in any state can be used.

In the case where a plurality of components are separated and stored for each component, each component may be prepared in the form of an aqueous solution. These aqueous solutions may be mixed at the time of use, and diluted with water as needed to prepare a working solution. In this case, for example, it may be classified into two types of oxidizing agents and other solutions, or three types of oxidizing agents and abrasive grains, and other solutions.

In addition, in the case of being stored as a concentrate, as long as When it is used, water or an aqueous solution may be added to the concentrate to be diluted, and it may be adjusted to a use liquid.

The substrate to be polished is specifically formed on a substrate (not shown) as shown in Fig. 1(a), and is covered with an insulating film 1 provided with a plurality of grooves (recesses) 2 to cover the insulating film. The barrier metal film 4 formed in a manner of 1 and the metal film 5 formed to cover the barrier metal film 4 are roughly configured. The region between the trenches 2 of the insulating film 1 is a space 3. The barrier metal film 4 and the metal film 5 which are formed by embedding the recesses 2 are divided into a plurality of CMP processes using a polishing composition, and finally a plurality of wires 2' are formed.

Further, the main polishing target used in the production of the substrate by using the polishing composition of the preferred embodiment of the present invention is the metal film 5 and the barrier metal film 4 formed on the insulating film 1. However, when the metal film 4 is polished and removed to the space of the insulating film 1, the insulating film (the portion of the space 3) adjacent to the metal film 5 or the barrier metal film 4 is slightly polished, so the insulating film is also Become an object of grinding.

The metal film 5 is preferably an alloy containing copper, aluminum, iron, tungsten or any of these, and is particularly preferably copper or a copper alloy. With respect to the metal film 5 composed of such a material, the polishing composition of the present invention as a preferred embodiment can exhibit particularly excellent effects.

The barrier metal film 4 is preferably a platinum group metal containing ruthenium, nickel, titanium, rhodium, platinum, or the like, or an alloy of any of them, and is preferably a ruthenium or osmium alloy. The polishing composition of the preferred embodiment of the present invention exhibits particularly excellent effects on the barrier metal film 4 composed of such a material.

In addition, the insulating film 1 (interlayer insulating film) may, for example, be an inorganic interlayer insulating film containing a large amount of cerium oxide film, hydroxysesquioxanes (HSQ), methyl sesquiterpene oxide (MSQ) or the like. Or an organic interlayer insulating film such as a film composed of benzocyclobutene. Further, a low dielectric interlayer insulating film having voids may be used as the interlayer insulating film.

Further, as the polishing apparatus, a holder having a substrate that holds the object to be polished and a polishing holder to which the polishing cloth is attached can be used.

Here, as the polishing cloth, a nonwoven fabric, a foamed polyurethane, or the like can be used, and there is no limitation on the material. Further, it is also possible to use a polishing cloth in which grooves are provided in each of the longitudinal and lateral directions and the concentric shape.

(Step of grinding the metal film 5 and blocking the metal film 4)

Next, the metal film 5 and the barrier metal film 4 are polished. First, while the polishing composition of the preferred embodiment of the present invention is supplied to the polishing cloth of the polishing apparatus, the substrate provided with the metal film 5 and the barrier metal film 4 is pressed against the polishing cloth. Then, in a state where the substrate is pressed against the polishing cloth, the polishing platen is rotated in the in-plane direction with respect to the substrate. Thereby, the metal film 5 is removed as shown in FIG. 1(b), and the barrier metal film 4 in the space 3 is exposed. At this point, the grinding is temporarily ended.

Further, the polishing conditions can be changed, and the barrier metal film 3 on the polishing space 3 is removed as shown in Fig. 1(c) to expose the insulating film 1 in the space 3. The polishing conditions are as long as they are removed in the metal film 5 The removal of the barrier metal film 4 may be carried out under the most suitable conditions.

After the polishing step is completed, the substrate is sufficiently washed in running water, and then the water droplets adhering to the substrate are left behind by a spin dryer or the like to be dried. By the above manner, the manufacture of the substrate of the polishing composition of the present invention is completed.

The rotation speed of the polishing plate varies depending on the structure or size of the polishing device. Therefore, the rotation speed may be appropriately set in accordance with the conditions of the polishing device. For example, when a general grinder is used, it is preferably rotated at a rotation speed of 10 to 500 m/min, more preferably 20 to 300 m/min, and particularly preferably 30 to 150 m/min.

When the metal film 5 and the metal film 4 are polished, it is preferable to rotate not only the polishing plate but also the substrate. Although the number of rotations of the substrate may be approximately the same as the number of rotations of the polishing platen, the number of rotations of the substrate may be increased or decreased with respect to the number of rotations of the polishing platen. Further, these polishing conditions may be changed during the polishing, and for example, the rotation speed may be changed in the middle of the polishing step.

Further, although the substrate is pressed against the polishing cloth via the bracket, the pressure at the time of pressing is preferably in the range of 0.1 to 100 kPa, and more preferably in the range of 0.6 to 35 kPa. Very good in the range of 0.6~20kPa. By setting the pressure at the time of pressing to be within this range, the in-plane uniformity of the metal film 5 or the barrier metal film 4 and the flatness of the pattern can be satisfied.

During this polishing step, the polishing composition of the present invention as a preferred embodiment is continuously supplied to the polishing cloth by a pump or the like. Research The supply rate of the polishing composition of the rubbing cloth may be appropriately set in accordance with the size of the polishing apparatus or the substrate. For example, in the case of using 8 Å wafers (200 mm wafer), it is preferably set to 10 to 1000 ml/min, more preferably 50 to 500 ml/min, and set to 50 to 300 ml/min. good. Further, the supply speed may be changed in the middle of the polishing step.

In the case where the polishing apparatus is used in an environment close to room temperature, the temperature adjustment of the polishing composition may not be performed. On the other hand, in the case where the temperature or the polishing rate is insufficient due to the installation environment of the polishing apparatus, the temperature of the polishing composition may be appropriately adjusted. The temperature of the polishing composition is preferably in the range of 0 to 100 ° C, more preferably in the range of 10 to 50 ° C, and particularly preferably in the range of 15 to 40 ° C. The metal film 5 can be polished at a sufficient speed by setting the temperature of the polishing composition within this range. On the other hand, if the temperature of the polishing composition is less than 0 ° C, the polishing rate for the metal film 5 is lowered, and the dispersion medium is frozen, which is less preferable. Further, if the temperature of the polishing composition exceeds 100. At °C, there is a fear that a side reaction caused by a dispersion medium or the like due to heat is less preferable.

According to the method for producing a substrate using the polishing composition of the preferred embodiment of the present invention, since the abrasive grains are sufficiently dispersed in the dispersion medium, the polishing rate of the barrier metal film can be suppressed. Further, since about 100% of the nonionic water-soluble polymer adsorbs to the abrasive grains and hardly dissociates in the dispersion medium, adsorption of the nonionic water-soluble polymer to the insulating film can be prevented. Thereby, the research of the insulating film can be prevented The grinding rate is reduced. Therefore, even if the substrate having the fine wiring composed of the metal film 5 is formed at a high density, corrosion can be suppressed and formed with high flatness.

Further, the polishing composition of the present invention is different from the conventional polishing composition in that the nonionic water-soluble polymer in the solvent is almost coated with the abrasive particles, but the properties other than the above effects are not easily changed. . Therefore, the steps or conditions are not changed, and it can be used in the same manner as the conventional polishing composition.

[Examples]

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited by the examples.

<Modulation of abrasive grain composition 1>

1.0 g of a colloidal cerium oxide (manufactured by Fusang Chemical Co., Ltd., PL2) having a primary average particle diameter of 25 nm and a secondary average particle diameter of 50 nm was mixed with water, and water was added to make the whole 250 g, and the preparation was as shown in Table 1. The abrasive particle composition 1 is shown.

<Modulation of abrasive grain composition 2>

1.0 g of colloidal cerium oxide (PL2 manufactured by Fusang Chemical Co., Ltd.) was mixed with water, and 0.05 g of the nonionic water-soluble polymer was mixed while stirring, and water was added to make the whole 250 g. Coating the mixture with a nonionic water-soluble polymer by stirring the mixture for more than 30 minutes Phlegm. As the nonionic water-soluble polymer, polyvinylpyrrolidone (manufactured by Sigma-Aldrich, polyvinylpyrrolidone 10k, mass average molecular weight: 10,000) was used. The abrasive grain composition 2 shown in Table 1 was prepared by the above manner.

<Modulation of Composition 1>

0.7 g of oxalic acid dihydrate was added to water and stirred to dissolve. Next, 0.7 g of dodecylbenzenesulfonic acid was added and stirred. Next, 29% aqueous ammonia (3.6 g of ammonia) was added and stirred. Next, 0.1 g of N-vinylimidazole was added and stirred. Next, 0.5 g of octanoic acid as a component D was added and stirred. Next, 1 g of hexanoic acid was added and stirred. Next, 0.07 g of benzimidazole was added and stirred. Finally, water was added to make the whole 250 g and stirred. Composition 1 was prepared by the above method. The composition of the composition 1 is shown in Table 1.

<Modulation of Composition 2>

0.7 g of oxalic acid dihydrate was added to water and stirred to dissolve. Next, 0.7 g of dodecylbenzenesulfonic acid was added and stirred. Next, 29% aqueous ammonia (3.6 g of ammonia) was added and stirred. Next, 0.1 g of N-vinylimidazole was added and stirred. Next, 0.5 g of octanoic acid as a component D was added and stirred. Next, 1 g of hexanoic acid was added and stirred. Next, 0.07 g of benzimidazole was added and stirred. Next, 0.05 g of polyvinylpyrrolidone (manufactured by Sigma-Aldrich, polyvinylpyrrolidone 10k, mass average molecular weight: 10,000) was added and stirred. Finally, Tim Water was added to make the whole 250 g and stirred. The composition 2 was prepared by the above method. The composition of the composition 2 is shown in Table 1.

Next, a substrate (wafer) shown below is prepared.

‧ Blank wafer: A TEOS oxide film (tantalum oxide film), a tantalum film (metal barrier film), and a copper film are laminated on a tantalum wafer of 8 turns, and each film is uniformly laminated.矽 Wafer.

‧Graphic wafer: A tantalum oxide film 1 is formed on a tantalum wafer of 8 turns, and a trench (concave portion) 2 having a depth of 500 nm and a width of 100 μm is provided on the tantalum oxide film 1 at a pitch of 100 μm to cover the tantalum oxide film. In the first embodiment, a barrier metal film 4 made of ruthenium having a thickness of 25 nm is formed, and a metal film 5 made of a copper film having a thickness of 1100 nm is formed so as to cover the barrier metal film 4, as shown in Fig. 1(a). Wafer wafer.

(Example 1)

250 g of the composition 1 and the abrasive particle composition 2 shown in Table 1 were separately mixed and stirred each time. Next, 20 g of ammonium persulfate and water were mixed to make the whole of 500 g, and the oxidizing agent shown in Table 1 was prepared. This oxidizing agent was added to an equal amount of the mixture of the composition 1 and the abrasive grain composition 2, and the polishing composition was adjusted to have a total of 1000 g. The pH is 9.3. The polishing properties were evaluated by polishing the composition by grinding the blank wafer and the pattern wafer, respectively. In addition, the grinding machine was a SH-24 manufactured by SpeedFam. Further, the rotation speed of the wafer was set to 83 rpm, the rotation speed of the polishing plate was set to 83 rpm, the supply speed of the polishing composition was 150 ml/min, and the pressing force of the polishing pad was set to 13.8 kPa. In addition, research The grinding pad was an IC1000 (kgroove) manufactured by Rodel-Nitta.

<Evaluation method>

The items of the evaluation method are shown below.

‧Cuting speed of copper film and ruthenium film: The thickness of the copper film and the barrier film is measured according to the resistance values of the copper film and the ruthenium film before and after polishing. The polishing rate was calculated based on the thickness of the copper film and the barrier film and the polishing time.

‧ Polishing speed of tantalum oxide film: The thickness of the tantalum oxide film before and after polishing was measured by an optical film thickness meter. The polishing rate was calculated from the thickness of the tantalum oxide film before and after the polishing and the polishing time.

(Comparative Example 1)

250 g of the composition 1 of Table 1 and the abrasive particle composition 1 were separately mixed and stirred. Next, 20 g of ammonium persulfate and water were mixed to make 500 g, and the oxidizing agent shown in Table 1 was prepared. This oxidizing agent was added to the same amount of the mixture of the composition 1 and the abrasive grain composition 1, and the whole was 1000 g, and the polishing composition of Comparative Example 1 containing no polyvinylpyrrolidone was used. The pH of the polishing composition of Comparative Example 1 was 9.2. The evaluation of the polishing characteristics by the polishing composition of Comparative Example 1 was the same as in Example 1.

(Comparative Example 2)

250 g of the composition 2 of Table 1 and the abrasive particle composition 1 were separately mixed and stirred. Next, mix 20g of ammonium persulfate with water to make it The oxidizing agent shown in Table 1 was prepared by being 500 g. This oxidizing agent was added to the same amount of the mixture of the composition 1 and the abrasive grain composition 1, and the whole was 1000 g, and the polishing composition of Comparative Example 2 containing polyvinylpyrrolidone was used. In the polishing composition of Comparative Example 2, pretreatment of colloidal cerium oxide was not carried out, and colloidal cerium oxide was not coated with polyvinylpyrrolidone. The pH of the polishing composition of Comparative Example 2 was 9.2. The evaluation of the polishing property by the polishing composition of Comparative Example 2 was carried out in the same manner as in Example 1 except for the above.

The evaluation results of the polishing rates by blank wafers are shown in Table 2 for these Example 1 and Comparative Examples 1 and 2.

As shown in Table 2, when Comparative Example 1 in which a nonionic water-soluble polymer was not added was compared with Comparative Example 2 to which a nonionic water-soluble polymer was added, the polishing rate in a copper film (metal film) was obtained. There was almost no difference in the polishing rate of the tantalum oxide film (insulating film), but the polishing rate of the tantalum film (barrier metal film) of Comparative Example 2 was significantly lower than that of Comparative Example 1.

In addition, the wafers of the embodiment 1 and the comparative example 1 are used. When the flatness of the substrate after polishing was examined, the depression in Example 1 was 31.4 nm, whereas in Comparative Example 1, it was 67.1 nm, and in Example 1, the depression was suppressed. In addition, as shown in FIG. 2, the recessed surface refers to a state in which the upper surface of the metal film 5 buried in the trench 2 is polished and excavated up to the depth dimension d. The dimension d was evaluated as a depression. In addition, as shown in FIG. 3, the entire region in which the grooves (concave portions) 2 and the space 3 are provided is excessively etched to form a recess having a depth e.

In the case of the polyvinylpyrrolidone in the polishing composition, as described in Reference 1, it is known that the adsorption of colloidal cerium oxide to about 10% contributes to the dispersion stability of colloidal cerium oxide. It is also known that this adsorption is irreversible and it is not known that it will not separate once adsorbed. The adsorption of the nonionic water-soluble polymer to the colloidal ceria is carried out by hydrogen bonding or van der Waals, and is not described in Japanese Patent No. 313027 or Japanese Patent Laid-Open Publication No. 2005-518091. The charge is different from that of colloidal cerium oxide. The polyvinylpyrrolidone has a guanamine bond, and the general guanamine bond has a pKb of about 2. Therefore, it is presumed that the polyvinylpyrrolidone does not substantially dissociate from the colloidal cerium oxide in the neutral to weakly alkaline which is the conditions for the present implementation. Other examples of the nonionic water-soluble polymer adsorbed to the colloidal cerium oxide are hydroxypropylmethylcellulose described in Reference 2.

Reference 1: Advances in Colloid and Interface Science, Volume 91, Issue 1, 19 March 2001, Pages1-112. pdf

Reference 2: Colloids and Surfaces A Physicochemical and Engineering Aspects, Volume 328, Issues 1-3, 1 October 2008, Pages 114-122. pdf

The amount of the polyvinylpyrrolidone added was 5 parts by mass based on 100 parts by mass of the colloidal ceria of Example 1 and Comparative Example 2. The polyvinylpyrrolidone is added in an amount such that it is adsorbed to the colloidal cerium oxide in an approximate amount. It can be seen that in Example 1 in which pretreatment of colloidal cerium oxide with polyvinylpyrrolidone was carried out, the polishing rate of the ruthenium film was lowered as compared with Comparative Examples 1 and 2.

From the above viewpoints, it is understood that by applying the nonionic water-soluble polymer to the abrasive grains, the polishing rate of the tantalum oxide film (insulating film) and the copper film (metal film) can be changed without changing the polishing rate. The polishing rate of the tantalum film is reduced.

It is disclosed in the specification of U.S. Patent No. 6,331,134 that the rate of polishing of the oxide film can be lowered by adding polyvinylpyrrolidone without lowering the barrier rate. The polyvinylpyrrolidone which is not adsorbed to the colloidal ceria or the like is adsorbed on the tantalum oxide film of the substrate to lower the polishing rate of the tantalum oxide film. The results of the specification of U.S. Patent No. 6,331,134 are completely different from the results of the present invention. The reason for this is presumed to be due to the difference in the state of presence of the polyvinylpyrrolidone dissolved in the solution.

In Example 1 and Comparative Example 2, the amount of polyvinylpyrrolidone (nonionic water-soluble polymer) added was 5 parts by mass relative to the colloidal cerium oxide (abrasive particles), and the colloidal cerium oxide system was relative to Polyvinylpyrrolidone is added in a sufficient amount. Polyvinylpyrrolidine In Example 1 in which the surface of the colloidal cerium oxide was coated with a ketone, the polishing rate of the ruthenium film was further reduced. According to the decrease in the polishing rate of the copper film in Comparative Example 2, it was found that the polyvinylpyrrolidone was added to the polishing composition before being applied to the polishing particles in advance, and the performance was further improved than the direct addition to the polishing composition.

In the above manner, by adding a small amount of the nonionic water-soluble polymer, the polishing rate of the copper film (metal film) is not lowered, and the polishing rate of the ruthenium film (barrier metal film) can be reduced. The effect of the present invention can be obtained by using a polishing composition for copper polishing in which a barrier metal film such as a ruthenium film is used as an etching stopper.

(Example 2)

In Example 2, the substrate was polished under the following conditions.

‧ Grinding machine: FRex200 made by Ebara Works

‧ Top ring rotation number: 50rpm

‧Table rotation: 100rpm

‧ polishing composition supply rate: 200ml / minute

‧ Pressure: 30kPa

‧ polishing pad: IC1000 (Perforate) made by Rodel-Nitta

Further, in Example 2, the same polishing composition as in Example 1 was used.

(Comparative Example 3)

In Comparative Example 3, the blank wafer was polished under the same conditions as in Example 2, except that the same polishing composition as in Comparative Example 1 was used. The evaluation results of these Example 2 and Comparative Example 3 are shown in Table 3.

According to the evaluation results of Table 3, even in the case of using a grinder different from that of Example 1, the polishing rate of the ruthenium film as the barrier metal film 4 can be lowered in the polishing composition to which the nonionic water-soluble polymer is added. Further, the polishing rates of the copper films of Example 2 and Comparative Example 3 did not change regardless of the presence or absence of the addition of the nonionic water-soluble polymer of the polishing composition.

(Reference example 1)

In the aqueous dispersion of colloidal cerium oxide, polyvinylpyrrolidone was added so as to be 5 parts by mass based on the colloidal cerium oxide, and the abrasive granule composition of Reference Example 1 was prepared by stirring for 30 minutes or more. Further, colloidal cerium oxide is a PL2 manufactured by Fuso Chemical Co., Ltd. having an average primary particle diameter of 25 nm and a secondary average particle diameter of 50 nm. Further, polyvinylpyrrolidone is a polyvinylpyrrolidone K30 manufactured by Nippon Shokubai Co., Ltd., and has a mass average molecular weight of 40,000.

(Reference example 2)

The abrasive grain composition of Reference Example 2 was prepared in the same manner as in Reference Example 1 except that the amount of the polyvinylpyrrolidone was changed to 20 parts by mass based on the colloidal cerium oxide.

(Reference Example 3)

The abrasive grain composition of Reference Example 3 was prepared in the same manner as in Reference Example 1 except that the amount of the polyvinylpyrrolidone was changed to 100 parts by mass based on the colloidal cerium oxide.

Table 4 shows the observation results of the amount of colloidal cerium oxide and polyvinylpyrrolidone added in Reference Examples 1 to 3 and the colloidal cerium oxide in the polishing composition.

In the abrasive grain composition of Reference Example 1, even after 3 days, the colloidal ceria was stabilized. On the other hand, in the abrasive grain compositions of Reference Examples 2 and 3, polyvinylpyrrolidone was rapidly clouded after being mixed with colloidal cerium oxide, and white precipitate of colloidal cerium oxide was observed over time. Dian. Based on this result, it can be considered that the excess polyvinylpyrrolidone in Reference Examples 2 and 3 acts to agglomerate the colloidal ceria.

[Industrial Applicability]

According to the polishing composition of the present invention, since the abrasive particles coated with the nonionic water-soluble polymer are sufficiently dispersed in the solvent, the polishing rate of the metal film or the barrier metal film as the wiring material can be suppressed.

Further, according to the polishing composition of the present invention and the method for producing a substrate using the polishing composition, since the nonionic water-soluble polymer can be prevented from being adsorbed on the insulating film, the polishing rate of the insulating film is not lowered. Therefore, even in the case of a substrate having an insulating film in which fine wiring is disposed at a high density, the etching of the insulating film during CMP processing can be suppressed, and the flatness of the substrate can be maintained at a high level.

1‧‧‧Insulation film

2‧‧‧ trench

2'‧‧‧ wiring

3‧‧‧ Space

4‧‧‧Barrier metal film

5‧‧‧Metal film

Claims (16)

A polishing composition comprising: (A) an oxidizing agent; (B) an acid selected from the group consisting of an amino acid and a carboxyl group having less than 8 carbon atoms or a mineral acid; (C) a sulfonic acid having a concentration of 0.01% by mass or more and having an alkyl group having 8 or more and 15 or less carbon atoms; (D) a fatty acid having a concentration of 0.001% by mass or more and having an alkyl group having 8 or more and 15 or less carbon atoms (E) a nonionic water-soluble polymer; (F) abrasive particles coated with the aforementioned nonionic water-soluble polymer; and (G) water as a dispersion medium, and having a pH of 7 to 11, relative to the foregoing 100 parts by mass of the abrasive grains, and 1 to 10 parts by mass of the above-mentioned nonionic water-soluble polymer. The polishing composition of claim 1, wherein the nonionic water-soluble polymer is polyvinylpyrrolidone. The abrasive composition of claim 1, wherein the oxidizing agent is a persulfate. The polishing composition according to claim 1, wherein the concentration of the oxidizing agent is 0.01 to 30% by mass based on the polishing composition. The polishing composition of claim 1, wherein the carboxylic acid is oxalic acid and/or hexanoic acid. The abrasive composition of claim 1, wherein the foregoing Sulfonic acid alkyl benzene sulfonic acid. The abrasive composition of claim 1, wherein the fatty acid is octanoic acid. The polishing composition according to claim 1, wherein the concentration of the abrasive grains is 0.01 to 10% by mass based on the polishing composition. The abrasive composition of claim 1, wherein the abrasive particles are colloidal cerium oxide. The abrasive composition of claim 1, further comprising benzotriazole, tolyltriazole, hydroxybenzotriazole, carboxybenzotriazole, benzimidazole, tetrazole, 2-quinolinecarboxylic acid At least one or two or more selected from (quinaldic acid), and the concentration thereof is 0.5% by mass or less. The polishing composition of claim 1, which is used for polishing a metal film and/or a barrier metal film of a concave portion of an insulating film formed on a substrate. A method for producing a polishing composition, which comprises (A) an oxidizing agent, (B) one or two or more acids selected from the group consisting of amino acids, carboxylic acids having less than 8 carbon atoms, and inorganic acids, ( C) a sulfonic acid having a concentration of 0.01% by mass or more and having an alkyl group having 8 or more and 15 or less carbon atoms, and (D) a fatty acid having a concentration of 0.001% by mass or more and having an alkyl group having 8 or more and 15 or less carbon atoms, (F') the abrasive particles and (E') of the nonionic water-soluble polymer in an amount of 1 to 10 parts by mass based on 100 parts by mass of the abrasive grains are mixed in water as a dispersion medium, and the pH is adjusted to 7 to 11 And coating the aforementioned abrasive particles with the aforementioned nonionic water-soluble polymer. A method for producing a polishing composition comprising the steps of: mixing a nonionic water-soluble polymer in an amount of from 1 to 10 parts by mass based on 100 parts by mass of the abrasive particles to the nonionic water-soluble polymer a pretreatment step of coating the above-mentioned abrasive grains, and one or more acids selected from the group consisting of (A) an oxidizing agent, (B) an amino acid, a carboxylic acid having a carbon number of less than 8, or a mineral acid (C) a sulfonic acid having a concentration of 0.01% by mass or more and having an alkyl group having 8 or more and 15 or less carbon atoms, (D) having a concentration of 0.001% by mass or more and having an alkyl group having 8 or more and 15 or less carbon atoms. The fatty acid and (F) the abrasive particles coated with the nonionic water-soluble polymer are mixed in water as a dispersion medium to adjust the pH to 7 to 11. A method for producing a substrate, which is a metal film or a barrier metal film formed in a concave portion of an insulating film provided on a substrate by the polishing composition according to any one of the first to eleventh aspects of the invention. Either or both. The method for producing a substrate according to claim 14, wherein the metal film is copper or an alloy containing copper. The method of manufacturing a substrate according to claim 14, wherein the barrier metal film is a tantalum or a tantalum alloy.