TW201321489A - Polishing solution composition for semiconductor wafer - Google Patents

Abstract

The topic of the present invention is to provide a polishing solution composition capable of effectively reducing LPD with its size below 50 nm on the wafer surface during polishing of the semiconductor wafer. The polishing solution composition for semiconductor wafer of the present invention comprises water, silicon dioxide particle, alkaline compound, water-soluble polymer compound, and polyethylene glycol, and satisfies the below-mentioned conditions (a) - (c). (a): the shape coefficient SF1 of the afore-mentioned silicon dioxide particle is 1.00-1.20; (b) the average primary particle size of the afore-mentioned silicon dioxide particle obtained by utilizing the nitrogen adsorption method is 5-100 nm, and the particle size variation coefficient CV value obtained from the graph analysis of the transmission electron microscope photo is 0-15%; and (c) the number average molecular weight of the afore-mentioned polyethylene glycol is 200-15,000.

Description

Slurry composition for semiconductor wafer

The present invention relates to a polishing liquid composition suitable for LPD improvement in mirror polishing of a surface of a semiconductor wafer.

A general semiconductor wafer manufacturing method is composed of the following steps: 1) a step of cutting a single crystal ingot to obtain a thin disk-shaped wafer, and 2) a chamfering step of chamfering the outer peripheral portion of the wafer, 3) a rubbing step of flattening the chamfered wafer, 4) an etching step of removing the processed deformation of the rubbed wafer, 5) a grinding step of mirroring the surface of the etched wafer, 6) washing and grinding Wafer cleaning step.

The polishing step is performed while the polishing liquid composition is supplied onto the surface of the polishing pad while the semiconductor wafer of the object to be polished is pressed against the polishing pad and moved relatively. The grinding step is generally carried out by a plurality of stages of primary grinding, secondary grinding, and final grinding. The purpose of primary polishing and secondary polishing is to remove deep scratches on the surface of the wafer generated during the rubbing or etching step. In contrast, the final polishing is performed to remove surface defects remaining after primary polishing and secondary polishing, and to accurately It is carried out by flattening. The evaluation criteria of the quality of the semiconductor wafer after the final polishing generally use LPD (light spot defect) and the degree of turbidity (degree of surface haze).

The LPD is a micro surface defect that causes irregular reflection when a specular semiconductor wafer is irradiated with strong light, and is caused by scratches caused by coarse abrasive grains or foreign matter during polishing or by adhering substances or particles due to abrasive grains or foreign matter. A work-affected layer caused by adhesion of abrasive grains, foreign matter, or the like.

On the other hand, the degree of turbidity is the degree of haze exhibited by the reflected light when the semiconductor wafer in the mirror state is irradiated with strong light. A semiconductor wafer having high flatness has less chaotic reflection and a good degree of haze. The smaller the value of the number of LPDs or the degree of haze, the higher the quality of the wafer.

The final grinding step for improving the degree of LPD or haze is generally carried out by adding an alkali compound to the cerium oxide particles dispersed in water, followed by adding a polishing liquid composition of the water-soluble polymer compound. The water-soluble polymer compound having stress relaxation energy not only reduces damage due to abrasive grains or foreign matter, but also has an effect of imparting hydrophilicity to the surface of the semiconductor wafer and preventing adhesion of abrasive grains or foreign matter. Further, by adding a compound having an alcoholic hydroxyl group which improves the wettability of the interface of the semiconductor wafer, the effect of reducing scratches and preventing adhesion can be further improved, and planarization with high precision can be realized.

On the other hand, in recent years, as the design of semiconductor wafers has progressed toward the miniaturization of the wiring width, the requirements for the LPD and the degree of turbidity of the semiconductor wafer have become higher. In particular, the LPD can be observed to a degree of 50 nm or less due to the rapid progress of the surface defect inspection device, whereby the suppression of defects of a significant degree of tens of nm can not achieve sufficient effects by the conventional polishing liquid composition.

Patent Document 1 discloses a polishing liquid composition containing hydroxyethyl cellulose, more than 0.005 mass%, and less than 0.5 mass% of polyethylene oxide, an alkali compound, water, and cerium oxide. However, it has not been shown to have an effect on the reduction of LPD below 50 nm.

Patent Document 2 discloses that when a spherical surface having high smoothness and a narrow particle size distribution and substantially no modified coarse cerium oxide fine particles as a component of a polishing composition is used, the polishing rate and the substrate to be polished are displayed. The surface roughness and the occurrence of linear scratches on the substrate to be polished are balanced. However, it is not clear to what extent the LPD reduction effect is.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] JP-A-2004-128089

[Patent Document 2] JP-A-2008-273780

An object of the present invention is to provide a polishing liquid composition capable of effectively reducing LPD having a size of 50 nm or less on a wafer surface during polishing of a semiconductor wafer.

The polishing liquid composition for a semiconductor wafer according to the present invention is a polishing liquid composition for a semiconductor wafer, comprising water, cerium oxide particles, an alkali compound, a water-soluble polymer compound, and polyethylene glycol, and Meet the conditions of (a) to (c) below,

(a): the shape factor SF1 of the cerium oxide particle represented by the following formula (1) is 1.00 to 1.20,

(1) SF1=(D _L ² ×π/4)/S

(However, D _{L is} the maximum length (nm) of the cerium oxide particles obtained by the transmission electron micrograph, and S is the projected area (nm ² ) of the cerium oxide particles),

(b): The average primary particle diameter of the cerium oxide particle obtained by the nitrogen adsorption method is 5 to 100 nm, and the particle diameter variation coefficient CV value obtained by image analysis of a transmission electron microscope photograph is 0~ 15% range,

(c): The number average molecular weight of the polyethylene glycol is 200 to 15,000.

The second aspect is the polishing liquid composition for a semiconductor wafer according to the first aspect, wherein the alkali compound is an inorganic salt and/or an ammonium salt of an alkali metal.

The third aspect is the polishing liquid composition for a semiconductor wafer according to the second aspect, wherein the inorganic salt of the alkali metal is lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate or carbonic acid. At least one selected from the group consisting of lithium hydrogen phosphate, sodium hydrogencarbonate, and potassium hydrogencarbonate.

The fourth aspect is the polishing liquid composition for a semiconductor wafer according to the second aspect, wherein the ammonium salt is from ammonium hydroxide, ammonium carbonate, ammonium hydrogencarbonate, tetramethylammonium hydroxide, tetraethylammonium hydroxide, At least one selected from the group consisting of tetramethylammonium chloride and tetraethylammonium chloride.

The fifth aspect is the polishing liquid composition for a semiconductor wafer according to the first aspect, wherein the water-soluble polymer compound is at least one selected from the group consisting of a cellulose derivative and a polyvinyl alcohol.

The sixth aspect is the polishing liquid composition for a semiconductor wafer according to the fifth aspect, wherein the cellulose derivative is carboxymethylcellulose, hydroxyethylcellulose, hydroxyethylmethylcellulose, or hydroxypropyl group. At least one selected from the group consisting of cellulose, hydroxypropylmethylcellulose, methylcellulose, ethylcellulose, ethylhydroxyethylcellulose, and carboxymethylethylcellulose.

The seventh aspect is the polishing liquid composition for a semiconductor wafer according to the fifth aspect, wherein the cellulose derivative is hydroxyethyl cellulose having a weight average molecular weight in terms of polyethylene oxide of 100,000 to 3,000,000.

The polishing liquid composition for a semiconductor wafer according to any one of the first aspect to the seventh aspect, wherein the content of the cerium oxide particles is based on a total mass of a polishing liquid composition for a semiconductor wafer. , 0.005 to 50% by mass.

The ninth aspect is the polishing liquid composition for a semiconductor wafer according to any one of the first aspect to the eighth aspect, wherein the content of the alkali compound is based on the total mass of the polishing liquid composition for a semiconductor wafer. 0.001 to 30% by mass.

The polishing liquid composition for a semiconductor wafer according to any one of the first aspect to the ninth aspect, wherein the content of the water-soluble polymer compound is a total mass of the polishing liquid composition for a semiconductor wafer. The benchmark is 0.01 to 2.0% by mass.

The polishing liquid composition for a semiconductor wafer according to any one of the first aspect, wherein the content of the polyethylene glycol is a total mass of the polishing liquid composition for a semiconductor wafer. The standard is 0.01 to 0.5% by mass.

According to the present invention, by combining the cerium oxide particles having a shape of a true spherical shape and uniformly controlling the particle size distribution and the polyethylene glycol of a specific molecular weight, it is possible to provide damage to the surface of the semiconductor wafer and prevent abrasive particles or foreign matter. A semiconductor wafer with a reduced LPD of 50 nm or less for attachment.

The polishing liquid composition for a semiconductor wafer of the present invention is one containing water and cerium oxide particles, an alkali compound, a water-soluble polymer compound, and polyethylene glycol.

[cerium oxide particles]

The shape factor SF1 of the cerium oxide particles represented by the following formula (1) is 1.00 to 1.20.

(1) SF1=(D _L ² ×π/4)/S

(However, D _{L is} the maximum length (nm) of the cerium oxide particles obtained from the transmission electron microscope photograph, and S is the projected area (nm ² ) of the cerium oxide particles).

In the above formula (1), D _{L is} the maximum length of the cerium oxide particles (the maximum length between any two points around the image) obtained by image analysis of a transmission electron microscope (TEM) photograph, and S is the projected area of the cerium oxide particles obtained by image analysis of a through-hole electron microscope photograph. In detail, the electronic data is fed into the image analysis device with a resolution of 150 dpi (dot/inch) scanning with a transmission electron microscope photograph at a magnification of 200,000 times, and the number of pixels occupied by the cerium oxide particles is converted. The area is used as the projected area. For example, in a photo of 200,000 times, since each inch becomes 127 nm, the length of one side is 0.847 nm, and the area of each point is converted to 0.717 nm ² .

SF1 calculates the maximum length D _L and the projected area S of the 1000 particles identified by the image analyzing device, and calculates the calculated value of the formula (1) for each particle, and uses the average value as SF1.

The closer SF1 is to 1.00, the closer the shape is to a true spherical shape. By dropping the value of SF1 within the above range, defects or damage on the semiconductor wafer can be reduced. In order to further reduce the LPD of the wafer surface in the present invention, SF1 is preferably in the range of 1.00 to 1.18, preferably in the range of 1.00 to 1.15.

The primary particle diameter of the cerium oxide particles obtained by the nitrogen adsorption method is 5 to 100 nm. When the polishing rate is lower than 5 nm, the particle agglomeration is likely to occur, and the stability of the polishing composition is lowered. Further, when it is larger than 100 nm, it is easy to cause scratches on the semiconductor wafer, and the flatness of the polished surface is deteriorated.

In the present invention, the primary particle diameter of the cerium oxide particles used is preferably in the range of 10 to 70 nm, more preferably 20, without lowering the polishing rate, exerting the effect of the particle shape, and reducing the LPD on the surface of the semiconductor wafer. Range of ~50nm.

The particle size variation coefficient CV of the cerium oxide particle represented by the following formula (2) is 0 to 15%.

(2) CV value (%) = σ / D _A × 100

(However, σ is the standard deviation of the particle diameter, and D _A is the average particle diameter).

In the above formula (2), σ and D _A are obtained by image analysis of a transmission electron microscope photograph. Specifically, the diameter of each particle is determined by using an image analysis device (for example, manufactured by NIRECO Co., Ltd.: LUZEX AP) for any 1000 particles in a transmission electron microscope photograph of cerium oxide particles. Calculate D _A (nm) and σ. The closer the CV value is to 0%, the more uniform the distribution.

In the present invention, in order to further reduce the LPD of the surface of the semiconductor wafer, the CV value is preferably 10% or less, more preferably 7% or less.

The cerium oxide particles are colloidal cerium oxide, and are preferably produced by using an aqueous citric acid solution or an alkyl phthalate as a raw material.

As for the method for preparing the cerium oxide particles, when an aqueous solution of citric acid is used as a raw material, an aqueous solution of citric acid obtained by de-alkaliizing an aqueous solution of citric acid or a small amount of an alkali compound added to a citric acid aqueous solution is preferably used. A method in which an aqueous solution is added to a heel solution to grow the particle size of the cerium oxide particles. In this case, the residual liquid component used is composed of water and an alkali compound, colloidal ceria particles having a primary particle diameter of 3 to 25 nm, or water and an alkali compound.

In the particle growth reaction of the cerium oxide particles, the reaction temperature is preferably from 90 to 150 °C. Further, the residual liquid SiO ₂ /M ₂ O (M is an alkali metal) molar is preferably from 0 to 40. Further, the addition rate of the aqueous solution of citric acid or the aqueous solution of hydrazine hydride is preferably set such that the SiO ₂ /M ₂ O (M is an alkali metal) molar ratio of the reaction medium rises by 0.01 to 0.5 in one minute.

In the method for producing the cerium oxide particles, when an alkyl phthalate is used as a raw material, it is preferred to add an alkyl phthalate to the residual liquid to grow the particle size of the cerium oxide particles. At this time, the components of the raffinate are composed of water and an alkali compound and colloidal ceria particles having a primary particle diameter of 3 to 25 nm, or consisting of water and an alkali compound.

In the particle growth reaction of the cerium oxide particles, the reaction temperature is preferably 45 ° C or higher and the boiling point of the reaction medium or lower. Further, the concentration of the alkali compound of the residual liquid is preferably from 0.002 to 0.1 mol per liter of the residual liquid, and the concentration of water is 30 mol or more per liter of the residual liquid. The amount of the alkyl phthalate to be added is preferably from 7 to 80 moles per mole of the alkali compound per mole of the atom in the residual liquid. The addition rate of the alkyl phthalate is preferably set such that the SiO ₂ /M'OH (M'OH is an alkali metal hydroxide or ammonium hydroxide) molar ratio of the reaction medium rises by 0.1 to 1.0 in one minute.

The cerium oxide particles may be adjusted to have a SiO ₂ concentration of 10 to 30% by mass, and a hydrothermal treatment at a temperature of 120 to 300 ° C for about 2 to 20 hours.

When the cerium oxide particles contain coarse particles of 0.5 μm or more, it is necessary to remove the coarse particles. The removal step of the coarse particles is exemplified by a forced sedimentation method or a precision filtration method. Filters used for precision filtration include deep filters, pleated filters, membrane filters, hollow fiber filters, and the like, and any of them may be used. Further, the filter may be made of cotton, polypropylene, polystyrene, polyfluorene, polyether oxime, nylon, cellulose, glass, or the like, and any of them may be used. The filtration accuracy of the filter is expressed by absolute filtration accuracy (capturing the size of particles of 99.9% or more), but in terms of production efficiency (processing time or blocking of the filter, etc.), the above-mentioned cerium oxide particles are preferably used. Filter processing with absolute filtration accuracy of 0.5μm to 1.0μm.

The content of the cerium oxide particles relative to the total mass of the polishing liquid composition (total mass of the polishing liquid composition) is generally 0.05 to 50% by mass, preferably 0.1 to 20% by mass, more preferably 5 to 10% by mass. quality%. When it is 0.05% by mass or less, the polishing performance cannot be sufficiently exhibited, and if it is 50% by mass or more, the stability of the polishing liquid composition is deteriorated.

[alkali compound]

The alkali compound is an inorganic salt and/or an ammonium salt of an alkali metal, and these functions function as a processing accelerator. The inorganic salt of the alkali metal is at least one selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, lithium hydrogencarbonate, sodium hydrogencarbonate, and potassium hydrogencarbonate. It is preferably sodium hydroxide, potassium hydroxide, sodium carbonate or potassium carbonate.

The ammonium salt is at least selected from the group consisting of ammonium hydroxide, ammonium carbonate, ammonium hydrogencarbonate, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetramethylammonium chloride and tetraethylammonium chloride. One of which is preferably ammonium hydroxide.

The amount of the base compound to be added is preferably different depending on the substance to be used, but is generally 0.01 to 30% by mass based on the total mass of the polishing liquid composition. In particular, when an alkali metal salt is used as the alkali compound, it is preferably 0.01 to 1.0% by mass, and when an ammonium salt is used as the alkali compound, it is preferably 0.01 to 5% by mass. When the addition amount is less than 0.01% by mass, the effect as a processing accelerator is insufficient, and conversely, even if it is added in an amount of 30% by mass or more, further improvement in polishing performance cannot be expected. Further, two or more kinds of the above-mentioned alkali compounds may be used in combination.

[Water-soluble polymer compound]

The water-soluble polymer compound is at least one selected from the group consisting of a cellulose derivative and a polyvinyl alcohol. The weight average molecular weight of the water-soluble polymer compound is measured by GPC (gel permeation chromatography), and the weight average molecular weight (Mw) in terms of polyethylene oxide is 100,000 to 3,000,000, preferably 300,000 to 2,500,000, more preferably 500,000~2,000,000.

The aforementioned cellulose derivative is derived from carboxymethylcellulose, hydroxyethylcellulose, hydroxyethylmethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, methylcellulose, ethylcellulose. And at least one selected from the group consisting of ethyl hydroxyethyl cellulose and carboxymethyl ethyl cellulose, more preferably hydroxyethyl cellulose.

The amount of the water-soluble polymer compound added is preferably from 0.01 to 2.0% by mass based on the total mass of the polishing liquid composition. When the amount is less than 0.01% by mass, the wettability of the surface of the semiconductor wafer after polishing is insufficient. On the other hand, when 2.0% by mass or more is added, the viscosity of the polishing composition becomes too high.

Since the cellulose derivative contains a foreign matter having a size of from micrometer to submicron, the foreign matter is preferably removed. The removal step of the foreign matter is preferably a precision filtration method. Filters used in precision filtration include deep filters, pleated filters, membrane filters, and hollow fiber filters, and any of them can be used. Further, the filter may be made of cotton, polypropylene, polystyrene, polyfluorene, polyether oxime, nylon, cellulose, glass, or the like, and any of them may be used. The filtration accuracy of the filter is expressed by absolute filtration accuracy (capturing the size of particles of 99.9% or more), but in terms of production efficiency (processing time or blocking of the filter, etc.), the cellulose derivative is preferably Filter processing with absolute filtration accuracy of 0.5μm to 1.0μm.

[polyethylene glycol]

The number average molecular weight of the polyethylene glycol is 200 to 15,000. In terms of LPD which further reduces the surface of the semiconductor wafer, the number average molecular weight is preferably 10,000 or less, more preferably 5,000 or less.

The amount of the polyethylene glycol added is 0.01 to 0.5% by mass based on the total mass of the polishing liquid composition. When the amount of polyethylene glycol added is less than 0.01% by mass, LPD cannot be improved. When the amount is more than 0.5% by mass, the wettability is too high, so that the sliding property is low, and the impedance of the polishing pad and the surface of the wafer is lowered. Therefore, the polishing rate is lowered and the LPD is deteriorated. In order to further reduce the LPD on the surface of the semiconductor wafer, the amount of polyethylene glycol added is preferably 0.02 to 0.4% by mass, more preferably 0.03 to 0.2% by mass.

[grinding liquid composition]

The polishing liquid composition of the present invention can also be prepared into a high concentration stock solution for storage or transportation, and used by being diluted with pure water when used in a polishing apparatus. The dilution ratio is 5 to 100 times, preferably 10 to 50 times.

The so-called semiconductor wafer to which the polishing composition of the present invention can be applied is a germanium wafer, a SiC wafer, a GaN wafer, a GsAs wafer, or a GaP wafer.

The polishing apparatus for polishing a semiconductor wafer has a one-side polishing method and a double-side polishing method, and any of the polishing liquid compositions of the present invention can be used.

When the polishing liquid composition of the present invention contains coarse particles of 0.5 μm or more, it is necessary to remove coarse particles before polishing. The step of removing the coarse particles is preferably a precision filtration method. Filters used for precision filtration include deep filters, pleated filters, membrane filters, and hollow fiber filters, and any of them can be used. Further, the filter may be made of cotton, polypropylene, polystyrene, polyfluorene, polyether oxime, nylon, cellulose, glass, or the like, and any of them may be used. The filtration accuracy of the filter is expressed by absolute filtration accuracy (capturing the size of particles of 99.9% or more), but in the polishing composition of the present invention, in terms of production efficiency (processing time or blockage of the filter, etc.), It is well treated with a filter with an absolute filtration accuracy of 0.5 μm to 1.0 μm.

[Examples]

[Analytical methods and test methods]

[1] Method for measuring SF1, [2] Method for measuring CV value, [3] Primary particle diameter determined by nitrogen adsorption method, [4] Determination of molecular weight of water-soluble polymer compound unless otherwise specified The following analytical methods [1] to [4] were measured or calculated, and the results are shown in Table 1.

[1] Method for measuring shape factor SF1 (true sphericity of particles) by image analysis

A cerium oxide particle of a photographic sample was taken 200,000 times by a transmission electron microscope (manufactured by JEOL Ltd., JEM-1010). The shape factor SF1 was calculated by the following equation (1) using an image analysis device (manufactured by NIRECO Co., Ltd.: LUZEX AP) for any 1000 particles in the obtained photograph projection.

(1) SF1=(D _L ² ×π/4)/S

(However, D _{L is} the maximum length (nm) of the cerium oxide particles obtained from the transmission electron microscope photograph, and S is the projected area (nm ² ) of the cerium oxide particles).

[2] Method for measuring particle size variation coefficient CV value (particle size distribution)

A cerium oxide particle of a photographic sample was taken 200,000 times by a transmission electron microscope (manufactured by JEOL Ltd., JEM-1010). The image analysis apparatus (manufactured by NIRECO Co., Ltd.: LUZEX AP) was used to measure the particle diameter of any 1000 particles in the obtained photograph projection image, and the standard deviation of the average particle diameter and the particle diameter was determined from the value. (2) Calculate the particle diameter variation coefficient CV value.

(2) CV value (%) = σ / D _A × 100

(However, σ is the standard deviation of the particle diameter, and D _A is the average particle diameter).

[3] Calculation method of average primary particle diameter of cerium oxide particles obtained by nitrogen adsorption method

After 10 ml of the aqueous sol of the cerium oxide particles was brought into contact with the cation exchange resin, the sample was dried in a mortar at 110 ° C for 12 hours. Further, it was dried at 300 ° C for 1 hour as a sample for measurement. The measurement apparatus of the nitrogen adsorption method (BET method) used Monosorb manufactured by Quantachrome. The average primary particle diameter of the cerium oxide particles was determined by the following formula (3) using the value of the specific surface area calculated by the nitrogen adsorption method.

(3) Average primary particle size (nm) = 2727 / specific surface area of nitrogen adsorption (m ² /g)

[4] Determination of molecular weight of water-soluble polymer compounds

The weight average molecular weight was measured by gel permeation chromatography under the following conditions.

Column: OHpak SB-806M HQ (8.0mmID×300mm)

Column temperature: 40 ° C

Dissolved solution: 0.1M sodium nitrate aqueous solution

Sample concentration: 0.11% by mass

Flow rate: 0.5mL/min

Injection volume: 200μL

Detector: RI (differential refractometer)

[5] Method for evaluating the polishing characteristics of semiconductor wafers

Water, ammonia, hydroxyethyl cellulose, and polyethylene glycol were added to the cerium oxide particles having different SF1 and CV values, and the polishing liquid composition was prepared and filtered by a filter having an absolute filtration accuracy of 1.0 μm. Using a polishing slurry in which the polishing composition was diluted to 40 times, the ruthenium wafer which was once ground under the same conditions was trimmed under the following conditions.

Grinder: 900 Φ single-sided processing machine

Load: 120g/cm ²

Platen speed: 40rpm

Rotating head revolutions: 40rpm

Diluting of the polishing composition: 350 ml/min

Grinding time: 5 minutes

Wafer: 矽 Wafer P ^- (100)

Apply a conventional SC1 wash to the polished wafer after finishing (in ammonia: hydrogen peroxide: water mixture ratio = 1:1~2:5~7 cleaning solution (SC1 liquid)) 75~85°C immersion treatment for 10~20 minutes) and SC2 washing (immersed in hydrochloric acid: hydrogen peroxide: water=1:1~2:5~7 cleaning solution (SC2 liquid) at 75~85°C After 10 to 20 minutes of treatment, the impurities on the surface of the wafer are removed. The LPD of the finished wafer surface after finishing polishing was measured using Surf Scan SP-2 manufactured by KLA-Tencor. LPD is represented by a number of 37 nm or more. In Table 1, (○) indicates that the number of LPDs of 37 nm or more per wafer is less than 80, (Δ) indicates that 80 or more are less than 200, and (×) indicates 200 or more.

[Example 1]

Adding water 156g to an aqueous cerium oxide sol 79g containing an average primary particle diameter of 37 nm, an SF1 of 1.11, a CV value of 7%, and a cerium oxide particle having a cerium oxide particle content of 30% by mass. 28 g of ammonia water of 28 g%, 59 g of hydroxyethylcellulose having a weight average molecular weight of 600,000, and 1.5 g of polyethylene glycol having a number average molecular weight of 1,000, a cerium oxide concentration of 8 mass%, and an ammonia content of 0.46 mass%, weight. A polishing liquid composition in which the average molecular weight of 600,000 hydroxyethyl cellulose is 0.22% by mass and the polyethylene glycol having a number average molecular weight of 1,000 is 0.1% by mass (the rest is water, the same applies hereinafter). The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity of 25 mPa s at 25 °C.

[Embodiment 2]

Except for the aqueous cerium oxide sol containing a cerium oxide concentration of 30% by mass of cerium oxide particles having an average primary particle diameter of 31 nm, an SF1 of 1.17, and a CV value of 7%, which is a raw material of methyl decanoate. In the same manner as in Example 1, a cerium oxide concentration of 8 mass%, ammonia of 0.46 mass%, a weight average molecular weight of 600,000 hydroxyethyl cellulose of 0.22 mass%, and a number average molecular weight of 1,000 polyethylene glycol of 0.1 mass were prepared. % of the slurry composition. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity of 3.2 mPa ‧ at 25 °C.

[Example 3]

Except for the aqueous cerium oxide sol containing a cerium oxide concentration of 30% by mass of cerium oxide particles having an average primary particle diameter of 37 nm, an SF1 of 1.20, and a CV value of 12% as a raw material. In the same manner as in Example 1, a cerium oxide concentration of 8 mass%, ammonia of 0.46 mass%, a weight average molecular weight of 600,000 hydroxyethyl cellulose of 0.22 mass%, and a number average molecular weight of 1,000 polyethylene glycol of 0.1 mass were prepared. % of the slurry composition. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity of 0.1 mPa ‧ at 25 °C.

[Comparative Example 1]

Except for the aqueous cerium oxide sol containing a cerium oxide concentration of 30% by mass of cerium oxide particles having an average primary particle diameter of 32 nm, an SF1 of 1.34, and a CV value of 32% as a raw material. In the same manner as in Example 1, a cerium oxide concentration of 8 mass%, ammonia of 0.46 mass%, a weight average molecular weight of 600,000 hydroxyethyl cellulose of 0.22 mass%, and a number average molecular weight of 1,000 polyethylene glycol of 0.1 mass were prepared. % of the slurry composition. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity of 0.1 mPa ‧ at 25 °C.

[Comparative Example 2]

Except for the aqueous cerium oxide sol containing a cerium oxide concentration of 30% by mass of cerium oxide particles having an average primary particle diameter of 29 nm, an SF1 of 1.89, and a CV value of 13% as a raw material of methyl decanoate as a raw material, In the same manner as in Example 1, a cerium oxide concentration of 8 mass%, ammonia of 0.46 mass%, a weight average molecular weight of 600,000 hydroxyethyl cellulose of 0.22 mass%, and a number average molecular weight of 1,000 polyethylene glycol of 0.1 mass were prepared. % of the slurry composition. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity of 3.2 mPa ‧ at 25 °C.

[Example 4]

Adding water 156g to an aqueous cerium oxide sol 79g containing an average primary particle diameter of 31 nm, an SF1 of 1.17, a CV value of 7%, and a cerium oxide particle having a cerium oxide concentration of 30% by mass of cerium oxide particles as a raw material. 28 g of 28% by mass aqueous ammonia, 59 g of hydroxyethyl cellulose having a weight average molecular weight of 1.2 million, and 1.5 g of polyethylene glycol having a number average molecular weight of 1,000, and having a cerium oxide concentration of 8 mass% and ammonia of 0.46 mass%, weight. A polishing liquid composition having an average molecular weight of 1.2 million hydroxyethyl cellulose of 0.22% by mass and a polyethylene oxide having a number average molecular weight of 1,000 was 0.1% by mass. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity at 25 ° C of 7.0 mPa ‧ s.

[Example 5]

Adding water 156g to an aqueous cerium oxide sol 79g containing an average primary particle diameter of 31 nm, an SF1 of 1.17, a CV value of 7%, and a cerium oxide particle having a cerium oxide concentration of 30% by mass of cerium oxide particles as a raw material. 28 g of 28% by mass aqueous ammonia, 59 g of hydroxyethyl cellulose having a weight average molecular weight of 1.7 million, and 1.5 g of polyethylene glycol having a number average molecular weight of 1,000, a cerium oxide concentration of 8 mass%, and an ammonia content of 0.46 mass%, weight. A polishing liquid composition in which hydroxyethylcellulose having an average molecular weight of 1.7 million was 0.22% by mass and polyethylene glycol having a number average molecular weight of 1,000 was 0.1% by mass. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity of 11.0 mPa ‧ at 25 °C.

[Embodiment 6]

In the same manner as in Example 5 except that the amount of the hydroxyethylcellulose having a weight average molecular weight of 1.7 million was 0.43 mass%, the cerium oxide concentration was adjusted to 8 mass%, the ammonia was 0.46 mass%, and the number average molecular weight was 1,000. The polyethylene glycol was 0.1% by mass of the polishing liquid composition. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity of 12.0 mPa ‧ at 25 °C.

[Comparative Example 3]

Adding water 156g to an aqueous cerium oxide sol 79g containing an average primary particle diameter of 31 nm, an SF1 of 1.17, a CV value of 7%, and a cerium oxide particle having a cerium oxide concentration of 30% by mass of cerium oxide particles as a raw material. 28 g of 28% by mass aqueous ammonia, 59 g of hydroxyethyl cellulose having a weight average molecular weight of 600,000, and a cerium oxide concentration of 8 mass%, ammonia of 0.46 mass%, and weight average molecular weight of 600,000 hydroxyethyl cellulose of 0.22. Mass% of the slurry composition. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity of 3.2 mPa ‧ at 25 °C.

[Embodiment 7]

Adding water 156g to an aqueous cerium oxide sol 79g containing an average primary particle diameter of 31 nm, an SF1 of 1.17, a CV value of 7%, and a cerium oxide particle having a cerium oxide concentration of 30% by mass of cerium oxide particles as a raw material. 28 g of ammonia water of 5 g%, 59 g of hydroxyethylcellulose having a weight average molecular weight of 600,000, and 1.5 g of polyethylene glycol having a number average molecular weight of 200, and a cerium oxide concentration of 8 mass% and an ammonia content of 0.46 mass%, weight. A polishing liquid composition having an average molecular weight of 600,000 hydroxyethylcellulose of 0.22% by mass and a polyethylene oxide having a number average molecular weight of 200 of 0.1% by mass. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity at 25 ° C of 3.1 mPa ‧ s.

[Embodiment 8]

In the same manner as in Example 7, except that polyethylene glycol having a number average molecular weight of 10,000 was used, hydroxyethylcellulose having a cerium oxide concentration of 8 mass%, ammonia of 0.46 mass%, and a weight average molecular weight of 600,000 was prepared to be 0.22 mass. %, a polyethylene glycol having a number average molecular weight of 10,000 is 0.1% by mass of a polishing liquid composition. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity of 0.1 mPa ‧ at 25 °C.

[Embodiment 9]

In the same manner as in Example 7, except that polyethylene glycol having a number average molecular weight of 15,000 was used, hydroxyethylcellulose having a cerium oxide concentration of 8 mass%, ammonia of 0.46 mass%, and a weight average molecular weight of 600,000 was prepared to be 0.22 mass. %, a polyethylene glycol having a number average molecular weight of 15,000 was 0.1% by mass of a polishing liquid composition. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity of 0.1 mPa ‧ at 25 °C.

[Comparative Example 4]

Except that polyethylene glycol having a number average molecular weight of 100 was used, the same procedure as in Example 7 was carried out, and hydroxyethyl cellulose having a concentration of cerium oxide of 8 mass%, ammonia of 0.46 mass%, and a weight average molecular weight of 600,000 was prepared. A polyethylene composition having a mass % and a number average molecular weight of 100 is 0.1% by mass of a polishing liquid composition. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity of 3.2 mPa ‧ at 25 °C.

[Comparative Example 5]

In the same manner as in Example 7, except that polyethylene glycol having a number average molecular weight of 50,000 was used, hydroxyethylcellulose having a concentration of cerium oxide of 8 mass%, ammonia of 0.46 mass%, and a weight average molecular weight of 600,000 was prepared to be 0.22 mass. %, a polyethylene glycol having a number average molecular weight of 50,000 is 0.1% by mass of a polishing liquid composition. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity of 0.1 mPa ‧ at 25 °C.

[Embodiment 10]

Adding water 156g to an aqueous cerium oxide sol 79g containing an average primary particle diameter of 31 nm, an SF1 of 1.17, a CV value of 7%, and a cerium oxide particle having a cerium oxide concentration of 30% by mass of cerium oxide particles as a raw material. 28 g of 28% by mass aqueous ammonia, 59 g of hydroxyethyl cellulose having a weight average molecular weight of 1.2 million, and 1.5 g of polyethylene glycol having a number average molecular weight of 600, and having a cerium oxide concentration of 8 mass%, ammonia of 0.46 mass%, and weight. A polishing liquid composition having an average molecular weight of 1.2 million hydroxyethyl cellulose of 0.22% by mass and a polyethylene glycol having a number average molecular weight of 600 of 0.1% by mass. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity at 25 ° C of 7.0 mPa ‧ s.

[Comparative Example 6]

Except for the aqueous cerium oxide sol containing a cerium oxide concentration of 30% by mass of cerium oxide particles having an average primary particle diameter of 32 nm, an SF1 of 1.34, and a CV value of 32% as a raw material. In the same manner as in Example 10, a cerium oxide concentration of 8 mass%, an ammonia content of 0.46 mass%, a weight average molecular weight of 1.2 million hydroxyethyl cellulose of 0.22 mass%, and a number average molecular weight of 600 polyethylene glycol of 0.1 mass were prepared. % of the slurry composition. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity of 6.8 mPa ‧ at 25 °C.

[Example 11]

The addition amount of the polyethylene glycol having a number average molecular weight of 1,000 was 0.05% by mass, and the same procedure as in Example 2 was carried out to prepare a cerium oxide concentration of 8 mass%, ammonia of 0.46 mass%, and a weight average molecular weight of 600,000. The hydroxyethylcellulose was 0.22% by mass, and the polyethylene glycol having a number average molecular weight of 1,000 was 0.05% by mass of a polishing liquid composition. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity of 3.2 mPa ‧ at 25 °C.

[Embodiment 12]

The addition amount of the polyethylene glycol having a number average molecular weight of 1,000 was 0.2% by mass, and the same procedure as in Example 2 was carried out to prepare a cerium oxide concentration of 8 mass%, ammonia of 0.46 mass%, and a weight average molecular weight of 600,000. The hydroxyethyl cellulose was 0.22% by mass, and the polyethylene glycol having a number average molecular weight of 1,000 was 0.2% by mass of a polishing liquid composition. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity of 3.2 mPa ‧ at 25 °C.

[Example 13]

The addition amount of the polyethylene glycol having a number average molecular weight of 1,000 was 0.4% by mass, and the same procedure as in Example 2 was carried out to prepare a cerium oxide concentration of 8 mass%, ammonia of 0.46 mass%, and a weight average molecular weight of 600,000. The hydroxyethyl cellulose was 0.22% by mass, and the polyethylene glycol having a number average molecular weight of 1,000 was 0.4% by mass of a polishing liquid composition. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity of 3.2 mPa ‧ at 25 °C.

[Comparative Example 7]

The addition amount of the polyethylene glycol having a number average molecular weight of 1,000 was 1.0% by mass, and the same procedure as in Example 2 was carried out to prepare a cerium oxide concentration of 8 mass%, ammonia of 0.46 mass%, and a weight average molecular weight of 600,000. The hydroxyethylcellulose was 0.22% by mass, and the polyethylene glycol having a number average molecular weight of 1,000 was 1.0% by mass of a polishing liquid composition. The resulting slurry composition had a pH of 10.7 and an Ostwald viscosity of 3.2 mPa ‧ at 25 °C.

As shown in Table 1, in Comparative Examples 1, 2 and 6 in which SF1 exceeded 1.20, Comparative Example 3 containing no polyethylene glycol, and Comparative Example 7 in which the amount of polyethylene glycol added was more than 0.5% by mass, polyethylene glycol The LPD evaluation results of Comparative Example 4 in which the number average molecular weight was less than 200 and Comparative Example 5 exceeding 15,000 were not good, and in Comparative Examples 1 to 13, the evaluation results of LPD were excellent.

[Industry possible use]

The polishing liquid composition for a semiconductor wafer of the present invention is excellent in finishing polishing performance, and a polishing liquid composition excellent in LPD reduction on the surface of a semiconductor wafer can be preferably used.

Claims (11)

A polishing liquid composition for a semiconductor wafer comprising water, cerium oxide particles, an alkali compound, a water-soluble polymer compound, and polyethylene glycol, and satisfying the following conditions (a) to (c), (a) The shape factor SF1 of the cerium oxide particle represented by the following formula (1) is 1.00 to 1.20, (1) SF1 = (D _L ² × π / 4) / S (however, D _L is a penetrating electron) The maximum length (nm) of the cerium oxide particles obtained by the micrograph, S is the projected area (nm ² ) of the cerium oxide particles, and (b): the average of the cerium oxide particles obtained by the nitrogen adsorption method. The primary particle diameter is 5 to 100 nm, and the particle diameter variation coefficient CV value obtained by image analysis of a transmission electron microscope photograph is 0 to 15%, and (c): the number average molecular weight of the polyethylene glycol is 200. ~15,000. The polishing liquid composition for a semiconductor wafer according to the first aspect of the invention, wherein the alkali compound is an inorganic salt and/or an ammonium salt of an alkali metal. The slurry composition for semiconductor wafers according to claim 2, wherein the inorganic salt of the alkali metal is lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate or lithium hydrogencarbonate. At least one selected from the group consisting of sodium hydrogencarbonate and potassium hydrogencarbonate. The slurry composition for semiconductor wafers according to claim 2, wherein the ammonium salt is from ammonium hydroxide, ammonium carbonate, ammonium hydrogencarbonate, tetramethylammonium hydroxide, tetraethylammonium hydroxide, and chlorination. At least one selected from the group consisting of tetramethylammonium and tetraethylammonium chloride. The polishing liquid composition for a semiconductor wafer according to the first aspect of the invention, wherein the water-soluble polymer compound is at least one selected from the group consisting of a cellulose derivative and a polyvinyl alcohol. The slurry composition for semiconductor wafers according to claim 5, wherein the cellulose derivative is carboxymethylcellulose, hydroxyethylcellulose, hydroxyethylmethylcellulose, hydroxypropylcellulose And at least one selected from the group consisting of hydroxypropylmethylcellulose, methylcellulose, ethylcellulose, ethylhydroxyethylcellulose, and carboxymethylethylcellulose. The polishing liquid composition for a semiconductor wafer according to claim 5, wherein the cellulose derivative is hydroxyethyl cellulose having a weight average molecular weight of 100,000 to 3,000,000 in terms of polyethylene oxide. The polishing liquid composition for a semiconductor wafer according to any one of claims 1 to 7, wherein the content of the cerium oxide particles is 0.005 based on the total mass of the polishing composition for a semiconductor wafer. 50% by mass. The polishing liquid composition for a semiconductor wafer according to any one of claims 1 to 8, wherein the content of the alkali compound is 0.001 to 30 by mass based on the total mass of the polishing composition for a semiconductor wafer. %. The polishing liquid composition for a semiconductor wafer according to any one of claims 1 to 9, wherein the content of the water-soluble polymer compound is 0.01 based on the total mass of the polishing composition for a semiconductor wafer. ~2.0% by mass. The polishing liquid composition for a semiconductor wafer according to any one of claims 1 to 10, wherein the content of the polyethylene glycol is 0.01% based on the total mass of the polishing composition for a semiconductor wafer. 0.5% by mass.