TWI640613B - Polishing composition and polishing method using the same - Google Patents

Abstract

An object of the present invention is to provide a polishing composition having excellent dissolution stability and capable of performing a polishing process at a high polishing rate, and a polishing method using the polishing composition.

As a solution, the present invention provides: [1] a polishing composition containing (A) component: one or more kinds of abrasive particles selected from diamond, boron nitride, boron carbide, and silicon carbide; and ( B) Ingredients: fatty acids having 10 to 22 carbon atoms, and (C) ingredients: non-ionic surfactants, and (D) ingredients: organic amine compounds, and (E) ingredients: grinding compositions for dispersion media, ( A) The average particle diameter of the abrasive grains of the component is more than 1.0 μm and 10.0 μm or less, and the content of the (C) component is 0.30 to 10% by mass, and the molar ratio of the (D) component of the (B) component [( D) / (B)] is 45/55 ~ 90/10, and [2] a polishing method which uses the polishing composition described in [1] above to grind and is selected from the group consisting of sapphire, silicon carbide, gallium nitride, and nitrogen A substrate made of one or more materials made of aluminum.

Description

Polishing composition and polishing method using the same

The present invention relates to a polishing composition for polishing a substrate material having high hardness and high brittleness, and a polishing method using the polishing composition.

Sapphire substrates used to make light-emitting diode (hereinafter simply referred to as "LED") devices, silicon carbide (SiC) substrates for power semiconductor devices, gallium nitride (GaN) substrates, and aluminum nitride (AlN) substrates Hard and highly brittle substrate material.

In recent years, sapphire substrates have been mostly used as growth substrates for GaN crystal film layers of LEDs. In addition, it is gradually expanding its use as a cover glass for the terminals of smart phones or tablet computers.

Silicon carbide (hereinafter simply referred to as "SiC") substrates have excellent heat resistance and voltage resistance, and have gradually been put into practical use as high-efficiency power semiconductor devices used in hybrid electric vehicles, solar power generation, information equipment, and home appliances. The substrate.

However, new materials such as sapphire or SiC are more difficult to manufacture, and because of high hardness and high brittleness, there are many difficulties in wafer processing technology. So there is The problem of higher material cost and processing cost.

After the sapphire substrate is drawn as a single crystal ingot by, for example, the CZ method, the cylindrical shape is cut out to obtain a desired crystal surface, and the wafer shape is cut by a wire saw. The wafer-shaped sapphire substrate is polished on both sides with a slurry containing GC abrasive grains using a double-sided grinder and flattened. After the GC abrasive particles have been polished, polishing marks and processing change layers remain on the sapphire substrate, which must be removed.

As such a removal step, for example, a slurry of diamond abrasive grains is dropped on a lithographic plate using a single-sided grinder, and a substrate is polished by applying a load while rotating the substrate and the lithographic plate (hereinafter simply referred to as " Packaging steps ").

In addition, in the case of using a sapphire substrate as a growth substrate for a GaN crystal film layer for an LED, in order to further improve the surface quality, a chemical mechanical polishing step of further reducing the surface roughness with a slurry containing colloidal silica is also performed.

As a slurry of diamond abrasive grains used in the packaging step, it is known to provide a polishing composition that averages hydrophilic abrasive grains (diamonds, etc.) by using a nitrogen-containing surfactant and a carboxylic acid-based polymer. It is dispersed in a solvent of a hydrocarbon oil to improve polishing performance (Patent Document 1). However, the base of the slurry of the grinding composition is a hydrocarbon oil, and a cleaning agent must be used to clean the lithographic plate or the object to be ground after the grinding operation, and there is a problem that the cleaning operation takes a long time.

When water or a water-soluble solvent is used in the base of the mud, the cleaning problem as described above will be improved. However, compared to oil-based mud, it lubricates Poor performance, and has the disadvantage that the surface roughness of the object to be polished is deteriorated upon completion.

In order to make up for the shortcomings of such a water-based slurry, a composition for deformation processing containing fatty acids having a carbon number of 10 to 22 is known (Patent Document 2). Patent Document 2 discloses that by adding the fatty acid, the lubricity of the composition is improved, and a good finished surface can be obtained.

However, since the solubility of the aforementioned fatty acid is low, in order to have the solubility stability of the fatty acid stably dissolved in the composition (hereinafter simply referred to as "dissolution stability"), at least one type of alkylene glycol is added. Alkyl ethers, polyols, and polymers of polyols.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 3973355

[Patent Document 2] Japanese Patent No. 4015945

Although the composition described in Reference 2 can obtain a good finished surface, it is not sufficient to obtain excellent dissolution stability and polishing processing at a high polishing rate, and there is still room for improvement.

An object of the present invention is to provide a polishing composition having excellent dissolution stability and capable of performing a polishing process at a high polishing rate, and to use a polishing composition therefor. Grinding method of grinding composition.

As a result of intensive studies, the inventors have found that a polishing composition comprising a fatty acid of a specific carbon number, a nonionic surfactant, and an organic amine compound in a dispersion medium can solve the aforementioned problems. In the polishing composition, the fatty acid and the organic amine compound form a salt, and the nonionic surfactant can improve the solubility of the salt, and can stably dissolve the fatty acid. It is considered that this can suppress the precipitation of the fatty acid in the polishing composition on the lithographic plate during the polishing process, and promote uniform contact between the polishing composition and the lithographic plate. As a result, the effect of improving the lubricity of the fatty acid contained in the polishing composition and the effect of improving the solubility and stability of the fatty acid by the nonionic surfactant and the organic amine compound will be multiplied. The effect of the present invention is exhibited.

This invention is based on the said knowledge.

That is, the present invention provides the following [1] to [13].

[1] A polishing composition containing (A) component: one or more kinds of abrasive particles selected from diamond, boron nitride, boron carbide, and silicon carbide; and (B) component: 10 or more carbon atoms 22 The following fatty acids, and (C) component: nonionic surfactant, and (D) component: organic amine compound, and (E) component: polishing composition of dispersion medium, average particle size of abrasive particle of (A) component The diameter is more than 1.0 μm and 10.0 μm or less, the content of the (C) component is 0.30 to 10% by mass, and the molar ratio [(D) / (B)] to the (D) component of the (B) component is 45 / 55 ~ 90/10.

[2] The polishing composition according to the above [1], wherein the content of the component (A) is 0.03 to 3.0% by mass, the content of the component (B) is 0.10 to 10% by mass, and the content of the (D) component is 1.0 to The content of 20% by mass and the content of (E) component is 60 to 98% by mass.

[3] The polishing composition according to the above [1] or [2], wherein the abrasive particles are diamond.

[4] The polishing composition according to any one of the above [1] to [3], wherein the fatty acid is at least one selected from the group consisting of lauric acid and octadecenoic acid.

[5] The polishing composition according to any one of the above [1] to [4], wherein the nonionic surfactant is one selected from the group consisting of polyetheramine and sorbitol-ethylene oxide adduct the above.

[6] The polishing composition according to any one of the above [1] to [5], wherein the non-ionic surfactant is selected from the group consisting of polyoxyethylene laurylamine, polyoxyethylene tallow alkylamine, and polyoxyl One or more of ethylene sorbitan monolaurate and polyoxyethylene sorbitan monooleate.

[7] The polishing composition according to any one of the above [1] to [6], wherein the organic amine compound is an alkanolamine.

[8] The polishing composition according to any one of the above [1] to [7], wherein the organic amine compound is triethanolamine.

[9] The polishing composition according to any one of the above [1] to [8], wherein the dispersion medium contains one or more selected from the group consisting of ethylene glycol, diethylene glycol, and propylene glycol.

[10] The polishing composition according to any one of the above [1] to [9], wherein the dispersion medium is a mixture of a water-soluble organic solvent and water, and The mass ratio of the water-soluble organic solvent (water-soluble organic solvent / water) is 30/70 to 95/5.

[11] The polishing composition according to any one of the above [1] to [10], wherein the dispersion medium is a mixture of one or more selected from the group consisting of ethylene glycol, diethylene glycol, and propylene glycol, and water.

[12] A polishing method using one or more materials selected from the group consisting of sapphire, silicon carbide, gallium nitride, and aluminum nitride, using a polishing composition according to any one of the above [1] to [11]. Composition of the substrate.

[13] The polishing method according to the above [12], wherein the substrate is a substrate for a light emitting diode made of sapphire.

According to the present invention, it is possible to provide a polishing composition which is excellent in dissolution stability during polishing of a high-hardness and high-brittleness material, and which can be polished at a high polishing rate, and a polishing method using the polishing composition.

[Form of Implementing Invention] <Polishing composition>

The polishing composition of the present invention contains (A) component: one or more kinds of abrasive grains selected from diamond, boron nitride, boron carbide, and silicon carbide, and (B) component: fatty acid having 10 to 22 carbon atoms , And (C) components: Non-ionic surfactant, and (D) component: organic amine compound, and (E) component: polishing composition of dispersion medium, the average particle size of the abrasive particles of (A) component is more than 1.0 μm and 10.0 μm or less The content of the component (C) is 0.30 to 10% by mass, and the molar ratio [(D) / (B)] to the component (D) of the component (B) is 45/55 to 90/10.

In addition, in this specification, "dissolution stability" means that a fatty acid is stably dissolved.

[(A) Component: Abrasive particles]

The polishing composition of the present invention contains (A) a component: one or more types of abrasive particles (hereinafter simply referred to as "(A) component") selected from diamond, boron nitride, boron carbide, and silicon carbide.

The diamond used as the abrasive grain is not particularly limited, but for example, natural diamond or artificial diamond is preferred.

The manufacturing method of artificial diamond is not specifically limited. Moreover, the artificial diamond may be a single crystal diamond or a polycrystalline diamond, and further, a single crystal diamond and a polycrystalline diamond may be mixed and used.

The boron nitride, boron carbide, and silicon carbide used as the abrasive particles are not particularly limited, but industrially synthesized fine particles or powders can be used.

The abrasive grain is one or more selected from diamond, boron nitride, boron carbide, and silicon carbide, preferably one or more selected from diamond and boron carbide, and still more preferably diamond.

These may be used alone or in combination of two or more.

The average particle size of the aforementioned abrasive grains [central diameter (D50), body The product standard] is more than 1.0 μm and 10.0 μm or less, preferably 1.5 to 8.0 μm, and still more preferably 2.0 to 6.0 μm. When the average particle diameter of the abrasive particles exceeds 1.0 μm, a sufficient polishing rate can be obtained, and if the average particle diameter is 10.0 μm or less, generation of polishing marks on the surface of the substrate to be polished can be suppressed. The average particle diameter of the abrasive particles was measured by the laser diffraction scattering method described in the examples.

The content of the component (A) is preferably 0.03 to 3.0% by mass, more preferably 0.06 to 1.5% by mass, still more preferably 0.09 to 1.0% by mass, and still more preferably 0.15 to 0.5% by mass relative to the total amount of the polishing composition. . (A) When the content of the component is 0.03% by mass or more, a sufficient polishing rate can be obtained, and when it is 3.0% by mass or less, the occurrence frequency of marks (scratches) caused by the agglomeration of the abrasive particles can be suppressed, and the relative The amount used in the obtained grinding speed has high economic advantages.

There is no particular limitation on the method for adding the polishing composition containing the abrasive particles. It is also possible to directly add abrasive particles to the dispersion medium of the (E) component and mix them. Alternatively, the abrasive particles may be mixed with water, preferably deionized water, and then mixed in the dispersion medium of the component (E). The mixing method is not particularly limited, but an electromagnetic stirrer, a THREE-ONE MOTOR, an ultrasonic homogenizer, and the like can be used.

[(B) component: fatty acid having 10 to 22 carbon atoms]

The polishing composition of the present invention contains a component (B): a fatty acid having a carbon number of 10 or more and 22 or less (hereinafter simply referred to as "(B) component").

The fatty acid of the component (B) is used to improve lubricity.

The carbon number of the fatty acid used in the present invention is 10 or more, preferably 12 or more from the viewpoint of lubricity, and 22 or less, preferably 20 or less, and more preferably from the same viewpoint. It is 18 or less. If the carbon number of the fatty acid is 10 or more, metal corrosion is suppressed, and at the same time, it has lipophilicity, so lubricity can be improved. If the carbon number of the fatty acid is 22 or less, the dispersion medium contains water-soluble glycol and the like. In the case of an organic solvent, since it has solubility, good solubility stability can be obtained. The fatty acid may be linear or branched.

Examples of the fatty acids include saturated fatty acids such as capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and behenic acid; and unsaturated fatty acids such as octadecenoic acid, linoleic acid, and erucic acid. . In the present invention, among these, in order to reduce the surface tension of the polishing composition and to improve the permeability between the substrate and the lithographic plate, the entire polishing composition is preferably selected from the viewpoint of imparting high efficiency to polishing. One or more of lauric acid and octadecenoic acid, and more preferably lauric acid. These may be used alone or in combination of two or more. However, the fatty acid as the component (B) does not include these metal salts.

(B) The content of the component is preferably 0.10 to 10% by mass, more preferably 0.50 to 8.0% by mass, more preferably 1.0 to 6.0% by mass, and even more preferably 3.0 to 6.0, relative to the total amount of the polishing composition. quality%. (B) If the content of the component is 0.10% by mass or more, a sufficient acceleration and improvement effect of the grinding speed can be obtained. If it is 10% by mass or less, an acceleration and improvement effect of the grinding speed can be obtained. At the same time, from the point of solubility, It can suppress the precipitation of fatty acids and improve the dissolution and stability effect of the polishing composition.

[(C) component: non-ionic surfactant]

The polishing composition of the present invention contains (C) component: a nonionic surfactant (hereinafter simply referred to as "(C) component"). The nonionic surfactant of the component (C) is used to improve the solubility stability of the fatty acid of the component (B).

When the non-ionic surfactant is contained in the polishing composition of the present invention, the interaction between the fatty acid and the organic amine compound existing as a salt in the polishing composition will not be hindered, and the solubility and stability of fatty acids can be improved.

From the viewpoint of improving the solubility and stability of fatty acids, the nonionic surfactant is preferably a nonionic surfactant having a polyoxyalkylene group, and still more preferably a polyoxyalkylene group and a fatty acid residue. Non-ionic surfactant.

The oxyalkylene group constituting the polyoxyalkylene group is preferably one or more selected from oxyethylene groups and oxypropylene groups, and more preferably oxyethylene groups. The average addition mole number of the oxyalkylene group is preferably from 2 to 30, and even more preferably from 4 to 20.

The carbon number of the aforementioned fatty acid residue is preferably 10 or more, more preferably 12 or more, more preferably 14 or more, and preferably 22 or less, still more preferably 20 or less, and even more preferably 18 or less.

From the viewpoint of improving the solubility and stability of fatty acids, the nonionic surfactant is preferably one or more selected from polyetheramines and sorbitol-ethylene oxide adducts, and more preferably sorbitol. Ester-ethylene oxide adduct.

Examples of polyetheramines include polyoxyethylene laurylamine, Carbon number of oxyethylene polyoxypropylene laurylamine, polyoxyethylene alkyl (palmyl) amine, polyoxyethylene stearylamine, polyoxyethylene oleylamine, polyoxyethylene tallow alkylamine, etc. 10 ~ 22 A saturated or unsaturated polyoxyalkylene aliphatic amine having a linear or branched chain hydroxyl group.

The hydroxyl group constituting the aforementioned polyoxyalkylene aliphatic amine is preferably 12 or more, more preferably 14 or more, and more preferably 20 or less, and still more preferably 18 or less from the viewpoint of improvement in polishing speed. The average addition mole number of the oxyalkylene group constituting the aforementioned polyoxyalkylene aliphatic amine is preferably 2 to 30, more preferably 4 to 20, and even more preferably 4 to 10.

Among these, from the viewpoint of increasing the polishing speed, they are selected from polyoxyethylene laurylamine, polyoxyethylene alkyl (palmyl) amine, polyoxyethylene oleylamine, and polyoxyethylene tallow alkylamine. One or more of these are preferred, and one or more selected from polyoxyethylene laurylamine, polyoxyethylene alkyl (palmyl) amine, and polyoxyethylene tallow alkylamine are more preferred, selected from polyoxyethylene Laurylamine and polyoxyethylene tallow alkylamine are more preferred, and polyoxyethylene tallow alkylamine is even more preferred.

The sorbitol-ethylene oxide adduct has a fatty acid residue, and the carbon number of the fatty acid residue is preferably 10 or more, still more preferably 12 or more, more preferably 14 or more, and more preferably 20 or less. Preferably it is 18 or less. The average addition mole number of the oxyalkylene group constituting the aforementioned sorbitol ester-ethylene oxide adduct is preferably 2 to 30, more preferably 8 to 25, and still more preferably 10 to 25.

Examples of the sorbitol-ethylene oxide adduct include polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, and polyoxyethylene Ethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, and the like are selected from the group of polyoxyethylene sorbates from the viewpoint of increasing the grinding speed. One or more of the alcohol monolaurate and polyoxyethylene sorbitan monooleate are preferred.

The nonionic surfactant is selected from the group consisting of polyoxyethylene laurylamine, polyoxyethylene tallow alkylamine, polyoxyethylene sorbitan monolaurate, and polyoxylate from the viewpoint of improving the polishing rate. One or more kinds of ethylene sorbitan monooleate are preferable, and one or more kinds are selected from polyoxyethylene tallow alkylamine and polyoxyethylene sorbitan monooleate, and polyoxyethylene tallow is more preferable. Alkylamines are more preferred.

The content of the component (C) is 0.30 to 10% by mass, preferably 0.50 to 8.0% by mass, still more preferably 0.70 to 7.0% by mass, and more preferably 1.0 to 5.0% by mass with respect to the total amount of the polishing composition. (C) If the content of the component is 0.30% by mass or more, the improvement of dissolution stability and the acceleration of the polishing rate will be obtained. If it is 10% by mass or less, the acceleration of the polishing rate will increase.

[(D) component: Organic amine compound]

The polishing composition of the present invention contains (D) component: an organic amine compound (hereinafter simply referred to as "(D) component"). The organic amine compound of the component (D) can achieve the acceleration and improvement effect of the polishing rate by using the fatty acid of the component (B) in combination.

The organic amine compound is preferably a low molecular weight organic amine compound having a molecular weight of 200 or less, and examples thereof include monoethanolamine, diethanolamine, Alkanolamines such as triethanolamine; alkylenediamines such as ethylenediamine and propylenediamine; polyolefin polyamines such as ethylenediamine and triethylenetetramine. The organic amine compound is preferably an alkanolamine, more preferably one or more selected from diethanolamine and triethanolamine, and still more preferably triethanolamine. These may be used alone or in combination of two or more. However, the organic amine compound as the component (D) does not include these salts.

(D) The content of the component is preferably 1.0 to 20% by mass, more preferably 2.0 to 15% by mass, more preferably 2.0 to 10% by mass, and even more preferably 3.0 to 5.0, relative to the total amount of the polishing composition. quality%. (D) If the content of the component is 1.0% by mass or more, the improvement of dissolution stability and the acceleration of the polishing rate will be obtained. If it is 20% by mass or less, the acceleration of the polishing rate will increase.

In the polishing composition of the present invention, the molar ratio [(D) / (B)] to (D) component of (B) component is 45/55 to 90/10, preferably 50/50 to 90 / 10, still more preferably 50/50 ~ 80/20, more preferably 50/50 ~ 75/25, even more preferably 50/50 ~ 70/30, even more preferably 50/50 ~ 60/40. If the molar ratio [(D) / (B)] is above 45/55, fatty acids will be dissolved stably at room temperature, and if the molar ratio [(D) / (B)] is below 90/10, then The acceleration effect of the grinding speed is high, and excellent economic and practical effects can be obtained.

[(E) component: dispersion medium]

The polishing composition of the present invention contains a component (E): a dispersion medium (hereinafter simply referred to as "(E) component"). The aforementioned dispersion medium contains a water-soluble organic solvent Better.

The solubility of water-soluble organic solvents in water at 20 ° C is preferably 10 g / 100 ml or more, more preferably 20 g / 100 ml or more, more preferably 30 g / 100 ml, even more preferably 40 g / 100 ml or more, and even more preferably Above 50g / 100ml is better, and evenly mixed with water at any ratio is even better.

As the water-soluble organic solvent, diols are preferred from the viewpoint of flammability or environmental impact. Specific examples of the diols include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, and polypropylene glycol. These may be used singly or in combination of two or more kinds in any ratio.

The water-soluble organic solvent is preferably one or more selected from the group consisting of ethylene glycol, diethylene glycol, and propylene glycol from the viewpoint of flammability or environmental load, viscosity, and solubility stability, and more preferably Glycol. By using these water-soluble organic solvents, since there is no volatile or peculiar odor, the working environment is not deteriorated, and the polishing composition of the present invention can be obtained. In addition, when a substrate is polished using a polishing composition containing such a water-soluble organic solvent, a local exhaust device or a mask for organic work is not required, and the operation is easy.

The content of the water-soluble organic solvent in the component (E) is preferably 30% by mass or more, more preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass, and more preferably It is 95% by mass or less, still more preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less. (E) If the content of the water-soluble organic solvent in the component is If it is 30% by mass or more, the acceleration and acceleration effect of the grinding speed can be obtained. If it is less than 95% by mass, it has a moderate viscosity. Therefore, the polishing composition can be stably retained on the lithographic plate to improve the efficiency of the polishing process.

(E) The content of the component is preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, and still more preferably 98% by mass or less relative to the total amount of the polishing composition. It is preferably 95% by mass or less. (E) If the content of the component is 60% by mass or more, the viscosity of the polishing composition will be reduced, the polishing composition can be stably retained on the lithographic plate, and the efficiency of the polishing process can be improved. High grinding speed.

The content of the water-soluble organic solvent is preferably 40% by mass or more, more preferably 50% by mass or more, more preferably 60% by mass or more, and more preferably 86% by mass or less with respect to the total amount of the polishing composition. It is preferably 80% by mass or less, more preferably 78% by mass or less, and even more preferably 75% by mass or less. When the content of the water-soluble organic solvent is 40% by mass or more, good dissolution stability can be obtained, and when it is 86% by mass or less, a high polishing rate can be obtained.

The component (E) may further contain water from the viewpoint of improving the dispersibility of the abrasive particles, and is preferably a mixture of a water-soluble organic solvent and water, and more preferably selected from ethylene glycol, diethylene glycol, And a mixture of one or more of propylene glycol with water, more preferably a mixture of ethylene glycol and water.

The mass ratio of the water-soluble organic solvent to water (water-soluble organic solvent / water), from the viewpoint of improving the dispersibility of the aforementioned abrasive particles, and from the viewpoint of improving the solubility stability and obtaining a higher polishing rate Jiawei 30/70 ~ 95/5, more preferably 50/50 ~ 90/10, more preferably 60/40 ~ 85/15, and even more preferably 70/30 ~ 80/20.

From the viewpoint of dissolution stability, the content of water is preferably less than 60% by mass, more preferably less than 40% by mass, and even more preferably less than 20% by mass relative to the total amount of the polishing composition. It is preferably 3.0% by mass or more, and still more preferably 5.0% by mass or more. If the water content is less than 60% by mass, the polishing rate tends to decrease slightly, but a practically sufficient polishing rate can be obtained. If the water content is 3.0% by mass or more and less than 40% by mass, it can be obtained Higher grinding speed.

The water used in the present invention is preferably water passed through a filter in order to prevent foreign matter from being mixed into the polishing composition, and pure water is more preferred. When producing the polishing composition of the present invention, it is possible to obtain a desired abrasive particle concentration by previously preparing abrasive particle dispersion water in which abrasive particles are dispersed in water, and then mixing the dispersed water with a water-soluble organic solvent.

The polishing composition of the present invention may contain other components in addition to the components (A) to (E), as long as the effects of the present invention are not impaired. For example, it may further contain an additive (pH adjuster) for adjusting pH. As the pH adjuster, a known acid or alkaline substance can be used. As the acid, for example, inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, and phosphoric acid can be used. Among these, hydrochloric acid and sulfuric acid are preferred. As the basic substance, ammonia water, sodium hydroxide, potassium hydroxide, tetramethylamine hydroxide, and the like can be used. Among these, sodium hydroxide and potassium hydroxide are preferred.

As other additives, as long as the effect of the present invention is not impaired, an additive for suppressing the proliferation of microorganisms in the polishing composition may be added. Bactericides, lubricants for improving lubricity, viscosity increasing agents, antifoaming agents, etc.

When an antifoaming agent is added, it is preferably a polyolefin diol derivative, and its content is preferably 0.10 to 3.0% by mass.

As a manufacturing place for the polishing composition, in order not to be mixed with impurities or other foreign matters, it is preferable to set the working place as a positive pressure in a clean room or a filter to remove airborne particles from the air. This is because if a foreign substance is mixed, there will be scratches on the substrate during polishing.

The viscosity of the abrasive composition of the present invention at 22 ° C is preferably 5 to 35 mPa. s, more preferably 10 ~ 30mPa. s. If the viscosity is set at 5mPa. s or more, the acceleration and acceleration effect of the grinding speed can be obtained. If it is set at 35mPa. Below s, the polishing composition can stably stay on the lithographic plate, improving the efficiency of the polishing process.

The viscosity at 22 ° C was measured by the method described in the examples.

The pH of the polishing composition of the present invention at 25 ° C is preferably 7 to 9, and more preferably 7 to 8. By setting the pH to 7 to 9, deterioration of the substrate can be suppressed.

The pH at 25 ° C was measured by the method described in the examples.

[Manufacturing method of polishing composition]

The method for producing the polishing composition of the present invention is not particularly limited, and the dispersion medium of the component (E) can be charged while being stirred in a beaker or a container. (D) The organic amine compound of a component. For stirring, an electromagnetic stirrer, THREE-ONE MOTOR, etc. can be used.

Next, a nonionic surfactant of the component (C) is added. After the component (C) and the component (D) are uniformly mixed, the fatty acid of the component (B) is added. Stir until component (B) is completely dissolved. Finally, the abrasive grains of the component (A) are put in and subjected to a dispersion treatment to make it uniform. For the dispersion treatment, an electromagnetic stirrer, a THREE-ONE MOTOR, an ultrasonic homogenizer, or the like can be used.

The polishing composition of the present invention can be used as a dispersion of abrasive particles as the component (A) of the reagent 1 and containing the components (B), (C), (D), and (E) as the reagent 2 Products made of two kinds of liquid reagents are transported and stored. The aforementioned reagents 1 and 2 can be mixed immediately before grinding, and then supplied to a grinding machine for use.

In addition, the abrasive grains of the component (A) may be contained in the reagent 1 in the form of abrasive grains dispersed in a certain amount of water. At this time, when used for grinding, the reagents 1 and 2 may be mixed and supplied to a grinder, or the reagent 1 containing the abrasive particle dispersion water and the reagent 2 containing the dispersion liquid may be separately supplied to a polishing plate. The grinding machine at this time is more expected to have a correction ring.

<Polishing method>

The polishing method of the present invention is a method of polishing a substrate of a material of high hardness and high brittleness, which is made of one or more materials selected from the group consisting of sapphire, silicon carbide, gallium nitride, and aluminum nitride, using the aforementioned polishing composition.

Among the aforementioned substrates, in order to obtain a higher polishing speed, A substrate for a light emitting diode made of precious stones is preferred.

Examples of the apparatus used in the polishing method of the present invention include single-sided and double-sided polishing machines. For example, as a single-side grinder, a rotary table that fixes a plate made of a metal or a resin containing a metal, a substrate holding portion (for example, a ceramic plate) that fixes a substrate below, and a pressing portion can be used. The pressing portion has a mechanism for rotating the substrate holding portion in such a manner that the substrate is pressed against the polishing surface of the lithographic plate. At this time, while supplying the polishing composition to a lithographic plate made of a metal or a metal-containing resin, the substrate fixed to the substrate holding portion is pressed against the lithographic plate with a specific polishing load to perform polishing.

As the polishing load in the polishing method of the present invention, a high polishing rate can be obtained by setting, for example, 100 to 500 g / cm ² . As the number of revolutions of the lithographic plate and the substrate holding portion, a high polishing speed can be obtained by setting, for example, 30 to 120 rpm.

The supply amount of the above-mentioned polishing composition in the polishing method of the present invention is set to, for example, 0.1 to 5 ml / min to obtain a high polishing rate. As the metal constituting the lithographic plate, iron, tin, copper, or the like can be used. In addition, as the resin constituting the lithographic plate, an epoxy resin, a melamine resin, or the like can be used.

The polishing method of the present invention can obtain a high polishing speed by using the aforementioned polishing composition in a packaging step of polishing a mirror surface of a high hardness and high brittleness material.

[Example]

Hereinafter, examples and comparative examples will be given more specifically. The present invention will be described, but the present invention is not limited to these examples.

[Average particle size of abrasive particles (central diameter (D50), volume basis)]

The average particle size of the abrasive particles was measured using a laser diffraction scattering particle size distribution measurement device (device name: Microtrac MT3000II, manufactured by Nikkiso Co., Ltd.) to measure the volume particle size distribution. The cumulative volume on the particle size side is a value of 50%.

0.1 g of abrasive particles were weighed in a sample bottle, and 9.9 g of pure water was added to prepare 1% by mass of abrasive particle dispersion water. The abrasive particle dispersion water was dispersed and treated with an ultrasonic homogenizer "US-300T" (model name, manufactured by Nippon Seiki Seisakusho) for 3 minutes, and then measured using the particle size distribution measuring device described above. The measurement conditions are shown below.

Particle permeability: through

Particle refractive index: 2.41 (diamond)

Particle shape: non-spherical

Solvent: water

Solvent refractive index: 1.333

Calculation form: MT3000II

〔Grinding test〕

Using the polishing compositions obtained in the examples and comparative examples, a sapphire substrate polishing test was performed. The conditions of the polishing test are shown below.

Grinder: "SLM-140" (product name, Fuji Nikko Machinery Industry Co., Ltd.)

Grinding load: 150g / cm ²

Number of revolutions of lithography: 61rpm

Number of rotation of pressurizing part: 63rpm

Correction circle revolution: 63rpm

Supply of grinding composition: 0.33ml / min

Lithography: 400mm diameter, copper lithography

Processing time: 20min

Substrate: 4 inch sapphire substrate

〔Grinding speed〕

The thickness of the sapphire substrate before and after polishing was measured using a pin gauge, and the polishing speed was calculated by the following formula (1)

Grinding speed (μm / min) = {[Sapphire substrate thickness before polishing (μm)]-[Sapphire substrate thickness after polishing (μm)]) / [Grinding time (min)] (1)

[Evaluation of Dissolution Stability]

The mixed liquids obtained in the examples and comparative examples were used as samples for evaluation of solubility and stability. After the samples for evaluation were stored at room temperature (25 ° C) and ice water at 0 ° C for 1 hour, the presence or absence of the precipitate was visually observed The following evaluation criteria are used to evaluate. The results are shown in Tables 1 to 7.

(Evaluation criteria)

A: There are no precipitates at room temperature and at 0 ° C.

B: No precipitates at room temperature, but precipitates at 0 ° C.

〔Viscosity〕

The mixed liquids obtained in the examples and comparative examples were used as measurement samples, and the viscosity of the mixed liquids was measured.

Vibration Viscometer: Viscomate VM-100A-L (model name, manufactured by Yamaichi Denki Co., Ltd.)

Measurement temperature: 22 ° C

[PH value]

The mixed liquids obtained in the examples and comparative examples were used as measurement samples, and the pH of the mixed liquids was measured.

pH meter: D-13 (model name, manufactured by Horiba)

Measurement temperature: 25 ° C

Examples 1 to 18, Comparative Examples 1 to 7, and Reference Example 1

The polishing composition was prepared by using the component compositions shown in Tables 1 to 7. The composition of each component is mass% relative to the total amount of the polishing composition, and each component is as described below. The water was ion-exchanged water.

Hereinafter, a method for preparing the polishing composition will be described.

First, the components (E), (D), and (C) are weighed in a beaker in this order, and stirred with an electromagnetic stirrer until uniform, and then mixed. Next, component (B) is added, and it stirs until it melt | dissolves, and a mixed liquid is obtained. The component (A) of the abrasive grains was further added to the mixed liquid to obtain a polishing composition.

Dissolution stability, viscosity, and pH were evaluated using the results obtained above. Mixing is performed. The evaluation of the dissolution stability obtained by using the aforementioned mixed solution, and the measured values of viscosity and pH were regarded as the evaluation of the dissolution stability of the polishing composition, and measured values of viscosity and pH.

The polishing test was performed using the obtained polishing composition.

[(A) Ingredient]

． Diamond: average particle size (central diameter, volume basis) D50 = 3.65 μm, manufactured by Beijing Grish (grade PCD G3.5)

[(B) Ingredient]

． Fatty acid: Lauric acid [made by Nippon Oil (Stock) Co., Ltd., trade name: NAA (registered trademark) -122]

[(C) component]

． Polyoxyethylene tallow alkyl amine [manufactured by Nippon Oil Co., Ltd., trade name: Nymeen (registered trademark) T2-210]

． Polyoxyethylene laurylamine [manufactured by Nippon Oil Co., Ltd., trade name: Nymeen (registered trademark) L-207]

． Polyoxyethylene sorbitan monolaurate [manufactured by Kao Corporation, trade name: Leo Doll Super TW-L120]

． Polyoxyethylene sorbitan monooleate [manufactured by Nippon Oil Co., Ltd., trade name: Nonion OT-221]

[(D) component]

． Triethanolamine (manufactured by Sanwa Oil & Fat Industrial Co., Ltd.)

[(E) Ingredient] (Water-soluble organic solvent)

． Glycol (manufactured by Yamaichi Chemical Industry Co., Ltd.)

． Diethylene glycol (manufactured by Kanto Chemical Co., Ltd.)

． Propylene glycol (made by ADEKA)

[Other ingredients] (Defoamer)

． Polyolefin diol derivative [manufactured by Nippon Oil Co., Ltd., trade name: Disfoam (registered trademark) CC-118]

(Fatty acid amidine)

． Diethanolammonium laurate [manufactured by Nippon Oil Co., Ltd., trade name: Star Home (registered trademark) DL]

． Stearylenoic acid diethanolammonium [manufactured by Nippon Oil Co., Ltd., trade name: Star Home (registered trademark) DO]

． Coconut oil fatty acid diethanolamidine [made by Nippon Oil, Inc., trade name: Star Home (registered trademark) F]

(Anionic Surfactant)

． Polyoxyethylene-alkyl ether-sulfate-triethanolamine salt [manufactured by Nippon Oil Co., Ltd., trade name: Persoft (registered trademark) EL-T]

[Table 1]

[table 3]

[table 5]

[TABLE 6]

[TABLE 7]

It can be seen that Examples 1 to 18 have better dissolution stability than Comparative Examples 1 to 7, and can obtain a higher polishing rate. This is considered to be because the fatty acid can be stably dissolved by adding a nonionic surfactant and an organic amine compound.

In Comparative Example 4, Comparative Example 5, and Comparative Example 6, lauric acid diethanolamide, octadecenoic acid diethanolamine, and coconut oil fatty acid diethanolamine were added in an amount of 5 mass% of fatty acid amine to replace fatty acids and organics. Amine compounds. Compared with Examples 1-18, the polishing speed is relatively low. In addition, Comparative Example 4 shows that it does not have solubility stability.

These results indicate that the addition of fatty acids and organic amine compounds greatly contributes to the improvement in polishing speed. In Examples 1 to 18, dissociable amine salts are formed by the addition of fatty acids and organic amine compounds. Therefore, it is considered that the affinity of fatty acids for lithography is increased. As a result, the lubricity is improved and the polishing speed is improved compared to fatty acid amidines. Also promoted.

Comparative Example 1 is a polishing composition without adding a surfactant, but the polishing rate is lower than that of Examples 1 to 18. Moreover, it was also shown that it does not have solubility stability.

Comparative Example 3 is a case where an anionic surfactant is used. Compared with Examples 1-18, the polishing speed is relatively low. This is because the fatty acid and the organic amine compound are present as salts in the polishing composition, and the nonionic surfactant may increase the solubility. On the other hand, it is thought that the anionic surfactant will hinder the interaction between the fatty acid and the organic amine compound, the fatty acid is more stable, will not be dissolved in the polishing composition, and good results cannot be obtained.

Example 18 is a polyolefin diol derivative in which 1% by mass of a defoamer is added. Similar to Examples 1 to 17, it has excellent dissolution stability and a high polishing rate. Thereby, when bubbles may be generated during polishing, it is shown that the effect of the present invention is not impaired even if an antifoaming agent is added to the polishing composition.

[Industrial availability]

The polishing composition of the present invention can be used as an abrasive in the mirror polishing step of a substrate with high hardness and high brittleness, such as a sapphire substrate for a light emitting diode (LED), a SiC substrate for a power semiconductor device, a GaN substrate, and an AlN substrate.

Claims (12)

A polishing composition comprising (A) component: one or more kinds of abrasive particles selected from diamond, boron nitride, boron carbide, and silicon carbide; and (B) component: fatty acid having carbon number of 10 or more and 22 or less And (C) component: nonionic surfactant, and (D) component: organic amine compound, and (E) component: containing one or more selected from ethylene glycol, diethylene glycol, and propylene glycol For the abrasive composition of a water-soluble organic solvent dispersion medium, the average particle size of the abrasive particles of the component (A) is more than 1.0 μm and less than 10.0 μm, and the content of the (C) component is 0.30 to 10% by mass, relative to (B). The molar ratio [(D) / (B)] of the component (D) is 45/55 to 90/10, and the content of the water-soluble organic solvent in the component (E) is relative to the total amount of the polishing composition. It is more than 50% by mass and less than 86% by mass. For example, the polishing composition of claim 1, wherein the content of (A) component is 0.03 to 3.0% by mass, the content of (B) component is 0.10 to 10% by mass, and the content of (D) component is 1.0 to 20% by mass And (E) content of a component is 60-98 mass%. The abrasive composition according to claim 1 or 2, wherein the abrasive particles are diamond. The polishing composition according to claim 1 or 2, wherein the fatty acid is at least one selected from the group consisting of lauric acid and octadecenoic acid. The polishing composition according to claim 1 or 2, wherein the non-ionic surfactant is one or more selected from the group consisting of polyetheramine and a sorbate-ethylene oxide adduct. The polishing composition according to claim 1 or 2, wherein the non-ionic surfactant is selected from the group consisting of polyoxyethylene laurylamine, polyoxyethylene tallow alkylamine, polyoxyethylene sorbitan monolaurate, and One or more of polyoxyethylene sorbitan monooleate. The polishing composition according to claim 1 or 2, wherein the organic amine compound is an alkanolamine. The polishing composition according to claim 1 or 2, wherein the organic amine compound is triethanolamine. The polishing composition according to claim 1 or 2, wherein the dispersion medium is a mixture of one or more water-soluble organic solvents and water selected from the group consisting of ethylene glycol, diethylene glycol, and propylene glycol. The polishing composition according to claim 1 or 2, wherein the dispersion medium is a mixture of a water-soluble organic solvent and water, and the mass ratio of the water-soluble organic solvent to water (water-soluble organic solvent / water) is 30/70 ~ 95/5. A polishing method for polishing a substrate made of one or more materials selected from the group consisting of sapphire, silicon carbide, gallium nitride, and aluminum nitride, using a polishing composition according to claim 1 or 2. The polishing method according to claim 11, wherein the substrate is a substrate for a light emitting diode made of sapphire.