KR20140004307A - Method of preparing ceria particle, ceria particle thereby and polishing slurry comprising the same - Google Patents

Abstract

The present invention relates to a method for manufacturing ceria particles, ceria particles manufactured thereby and polishing slurries comprising the same. The ceria particles manufactured by the method for manufacturing ceria particles of the present invention are usefully controlled in a crystal structure, a shape, a size and the like since the ceria particles are able to be synthesized in a supercritical condition or a subcritical condition, are able to exhibit excellent polishing properties such as scratch reduction and the like and are able to be economically and efficiently manufactured. Accordingly, the ceria particles are able to be applied to improved CMP technology according to design reduction and are able to be widely applied to fine polishing fields. The present invention is able to perform a polishing process suitable for the manufacture process of a semiconductor. [Reference numerals] (S100) Manufacture a solution containing ceria by mixing a metal salt aqueous solution containing a supercritical fluid and cerium salt; (S110) Produce ceria particles by putting the solution containing ceria in a reactor and making the solution containing ceria react under a supercritical condition; (S120) Separate and collect ceria particles from a solution containing ceria particles

Description

Method for producing cerium oxide particles, thereby cerium oxide particles and polishing slurry comprising the same {METHOD OF PREPARING CERIA PARTICLE, CERIA PARTICLE THEREBY AND POLISHING SLURRY COMPRISING THE SAME}

The present invention relates to a method for producing cerium oxide particles, cerium oxide particles thereby and a polishing slurry comprising the same.

Cerium oxide particles are highly functional ceramic materials widely used in catalysts, phosphors, cosmetics, abrasives, etc., and the chemical mechanical planarization process (CMP), which is one of the semiconductor manufacturing processes, is required due to the recent development of the semiconductor industry and the demand for highly integrated semiconductors. It is attracting attention as a main component of the polishing slurry used in the). The cerium oxide particles used as the CMP polishing slurry can generally be produced by a liquid phase method, a gas phase method, or a solid phase method. The liquid phase method is a method for producing cerium oxide particles directly from cerium salt by adding a pH adjuster such as ammonia to the cerium salt starting material. The liquid phase method has the advantage of being economical because the raw material cost and equipment cost are relatively low, but it is difficult to control the growth of particles because the reaction between the starting materials occurs easily from the nucleation stage. The vapor phase method is a method of directly producing cerium oxide particles by vaporizing a cerium metal salt precursor and then combining it with oxygen, and the like, and include flame combustion decomposition, gas condensation decomposition, plasma vaporization, or laser vaporization. However, the gas phase method has a problem that the unit cost and equipment cost of the cerium metal salt precursor are high, making it difficult to mass-produce. The solid phase method is a method for producing cerium oxide particles by heat-treating a precursor at a high temperature, and research on this has been actively conducted in recent years, but the solid phase method not only affects physical properties such as particle size of abrasive particles, but also shapes. There is a problem that affects the polishing rate, flatness, scratch generation, etc. during the semiconductor CMP process.

In view of the above problems, in recent years, interest in the method for producing cerium oxide particles having a particle size of a specific size or less and at the same time having a uniform particle size distribution is amplified.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for producing cerium oxide particles which can easily produce cerium oxide particles having a uniform and fine particle diameter.

Another object of the present invention is to provide a cerium oxide particle produced by the above production method.

Still another object of the present invention is to provide a polishing slurry comprising the cerium oxide particles as abrasive particles.

Still another object of the present invention is to provide a method of polishing a substrate using the polishing slurry.

However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

A first aspect of the present invention can provide a method for producing cerium oxide particles, which forms cerium oxide particles under supercritical or subcritical conditions.

According to one aspect of the present invention, the supercritical or subcritical condition may be a reaction temperature of 250 ° C. to 600 ° C. and a reaction pressure of 50 bar to 500 bar, but is not limited thereto.

According to one aspect of the invention, the supercritical or subcritical conditions are selected from the group consisting of supercritical or subcritical carbon dioxide, supercritical or subcritical alkanes, supercritical water or subcritical water, and supercritical or subcritical alcohols At least one of which may be used, but is not limited thereto.

According to one aspect of the invention, a step of preparing a cerium oxide-containing solution by mixing a metal salt aqueous solution comprising a supercritical or subcritical fluid and cerium salt; Introducing the cerium oxide-containing solution into a reactor to react under supercritical or subcritical conditions to form cerium oxide particles; And separating and recovering the cerium oxide particles from the solution containing the cerium oxide particles. However, the present invention is not limited thereto.

According to one aspect of the present invention, the cerium salt may include at least one selected from the group consisting of nitrate, sulfate, chloride, carbonate, acetate and phosphate of cerium, but is not limited thereto.

According to one side of the present invention, the aqueous metal salt solution may further include a salt of at least one metal selected from the group consisting of Zn, Co, Ni, Fe, Al, Ti, Ba and Mn, but is not limited thereto. It doesn't happen.

The second aspect of the present invention may provide cerium oxide particles prepared by the method according to the first aspect of the present invention.

According to one side of the present invention, the average particle diameter of the secondary particles of cerium oxide may be about 10 nm to about 0.5 μm, but is not limited thereto.

A third aspect of the invention, the cerium oxide particles according to the second aspect of the present invention; Abrasive additives; And a dispersing agent.

According to one side of the present invention, the polishing additive may include at least one selected from the group consisting of anionic polymer, nonionic polymer, ammonium salt, organic acid and pH adjusting agent containing a carboxyl group (COOH), It is not limited to this.

According to one aspect of the invention, the anionic polymer containing the carboxyl group (COOH), polyacrylic acid (polyacrylic acid), polysulfonic acid (polysulfonic acid), polyacrylamide / acrylic acid copolymer (polyacrylamide / acrylic acid copolymer), poly Selected from the group consisting of acrylic / sulfonic acid copolymers, polysulfonic acid / acrylamide copolymers, and polyacrylic acid / malonic acid copolymers At least one of which is to be included, but is not limited thereto.

According to one side of the present invention, the anionic polymer including the carboxyl group (COOH), may be about 0.01% to about 1% by weight of the polishing additive, but is not limited thereto.

According to one side of the present invention, the nonionic polymer may be a polyalkyl oxide, but is not limited thereto.

According to one aspect of the invention, the nonionic polymer, polyoxyethylene oxide (polyoxyethylene oxide; PEO), polyethylene oxide (polyethylene oxide) and at least one selected from the group consisting of polypropylene oxide (polypropylene oxide) It may be, but is not limited thereto.

According to one side of the present invention, the nonionic polymer may be about 0.001 wt% to about 1 wt% of the polishing additive, but is not limited thereto.

According to one side of the present invention, the organic acid, picolinic acid (nicotinic acid), nicotinic acid (nicotinic acid), isicotinic acid (isonicotinic acid), fusaric acid (fusaric acid), dinicotinic acid (dinicotinic acid) , Dipiconilic acid, lutinic acid, quinolic acid, glutamic acid, alanine, glycine, cystine, histidine ), Asparagine, guanidine, guanidine, hydrazine, ethylenediamine, formic acid, acetic acid, benzoic acid, oxalic acid, succinic acid, malic acid, maleic acid, maleic acid, malonic acid, citric acid, lactic acid, tricarballyic acid, tartaric acid, as Aspartic acid, glutaric acid, adipic acid, suberic acid and puma Acid (fumaric acid), phthalic acid (phthalic acid), pyridine-carboxylic acid (pyridinecarboxylic acid), and it may be to include at least one, but is selected from the group consisting of salt, but is not limited thereto.

According to one side of the present invention, the dispersing agent may include, but is not limited to, one or more amine groups and one or more carboxyl groups.

According to one aspect of the invention, the dispersant, a group consisting of serine, glutamine, glutine, betaine, proline, pyroglutamic acid and amino butyric acid It may be to include at least one selected from, but is not limited thereto.

A fourth aspect of the present invention can provide a method of polishing a substrate using the polishing slurry according to the second aspect of the present invention.

Since the cerium oxide particles produced by the method for producing cerium oxide particles of the present invention can be synthesized under supercritical or subcritical conditions, the crystal structure, shape and size can be easily controlled, and excellent polishing properties such as scratch reduction are possible. Can be produced economically and efficiently. Accordingly, the present invention can be applied to an improved CMP technique due to reduction in design, and thus can be widely applied to the field of fine polishing. Thus, a polishing process suitable for a semiconductor manufacturing process can be performed.

1 is a flow chart of the manufacturing process of the cerium oxide particles according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. Also, terminologies used herein are terms used to properly represent preferred embodiments of the present invention, which may vary depending on the user, intent of the operator, or custom in the field to which the present invention belongs. Therefore, the definitions of the terms should be made based on the contents throughout the specification. Like reference symbols in the drawings denote like elements.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between .

Throughout the specification, when a member is located on another member, it includes not only when a member is in contact with another member but also when another member exists between the two members.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a polishing slurry for initial step removal of the present invention and a method of polishing a substrate or a wafer using the polishing slurry will be described in detail with reference to embodiments and drawings. However, the present invention is not limited to these embodiments and drawings.

A first aspect of the present invention can provide a method for producing cerium oxide particles, which forms cerium oxide particles under supercritical or subcritical conditions.

The supercritical or subcritical condition can be, but is not limited to, a reaction temperature of about 250 ° C to about 600 ° C and a reaction pressure of about 50 bar to about 500 bar. Cerium oxide particle generation can be carried out in such supercritical or subcritical conditions. When the reaction temperature is less than about 250 ° C or the reaction pressure is less than about 50 bar, the size of the cerium oxide particles to be produced is increased, the particle size distribution is widened and the crystallinity is decreased. When the reaction temperature exceeds about 600 ° C , And when the reaction pressure exceeds about 500 bar, the high temperature and high pressure must be maintained, resulting in low economical efficiency.

In the present invention, the reaction time for producing the cerium oxide particles may take about 1 to about 30 minutes, or about 2 to about 10 minutes. If the reaction time is less than about 1 minute, there is a problem that the crystallinity is reduced, and if the reaction time exceeds about 30 minutes, there is a problem that the size of the nanoparticles is increased and the particle size distribution is widened.

The supercritical or subcritical condition may be to use at least one selected from the group consisting of supercritical or subcritical carbon dioxide, supercritical or subcritical alkanes, supercritical water or subcritical water, and supercritical or subcritical alcohol. And, depending on the type of reaction and the type of product, and the reaction conditions can be used, but is not limited thereto. Among these, as examples of the use of the supercritical or subcritical alkanes, alkanes having about 1 to about 10 carbon atoms may be used.

1 is a flow chart of the manufacturing process of the cerium oxide particles according to an embodiment of the present invention.

Referring to FIG. 1, first, a cerium oxide-containing solution may be prepared by mixing a metal salt aqueous solution including a supercritical fluid and a cerium salt (S100).

The supercritical fluid may be, for example, using at least one selected from the group consisting of supercritical carbon dioxide, supercritical alkanes, supercritical water, and supercritical alcohol, but is not limited thereto.

The cerium salt may include at least one selected from the group consisting of nitrate, sulfate, chloride, carbonate, acetate and phosphate of cerium, but is not limited thereto.

The aqueous metal salt solution may further include a salt of at least one metal selected from the group consisting of Zn, Co, Ni, Fe, Al, Ti, Ba, and Mn, but is not limited thereto.

Subsequently, the cerium oxide-containing solution may be introduced into a reactor and reacted under supercritical conditions to form cerium oxide particles (S110).

The supercritical conditions may include, but are not limited to, a reaction temperature of about 250 ° C to about 600 ° C and a reaction pressure of about 50 bar to about 500 bar.

The reactor can be designed to suit the desired particle distribution, and the reaction temperature and reaction pressure can be reacted by appropriately adjusting the injection speed, injection position, injection concentration, and the like of the fluid.

Additionally, after the step of reacting the cerium oxide-containing solution to form cerium oxide particles, the method may further include cooling the solution including the cerium oxide particles. In a cooling process, general methods, such as a heat exchanger and a cooler, can be used, for example.

Subsequently, the cerium oxide particles may be separated and recovered from the solution containing the cerium oxide particles (S120).

In the separating and recovering the cerium oxide particles, a general method of separating solids from a liquid, such as filtration using a filter having an appropriate pore size, or using a centrifuge, may be used.

Additionally, after the separating and recovering the cerium oxide particles, the cerium oxide particles may further include washing and drying the cerium oxide particles. In the washing step, for example, a general method such as washing with water or an organic solvent may be used, and in the drying step, for example, a method such as vacuum drying, oven drying, freeze drying and the like may be used. In the organic solvent washing, for example, methanol, ethanol, propanol, acetone, tetrahydrofuran and the like can be used.

The second aspect of the present invention may provide cerium oxide particles prepared by the method according to the first aspect of the present invention.

When the particle size of the cerium oxide particles is too small, the polishing rate for planarizing the substrate will be reduced. When the particle size is too large, the cerium oxide particles are difficult to planarize and mechanical disadvantages such as scratched polishing surfaces In consideration of occurrence, the average particle diameter of the secondary particles may be about 10 nm to about 0.5 mu m, but is not limited thereto.

A third aspect of the invention, the cerium oxide particles according to the second aspect of the present invention; Abrasive additives; And a dispersing agent.

According to one aspect of the invention, the polishing additive includes, for example, at least any one selected from the group consisting of anionic polymers, nonionic polymers containing a carboxyl group (COOH), ammonium salts, organic acids and pH adjusting agents. It may be, but is not limited thereto.

The anionic polymer including the carboxyl group (COOH) is, for example, polyacrylic acid, polysulfonic acid, polyacrylamide / acrylic acid copolymer, polyacrylic acid / sulfonic acid At least any one selected from the group consisting of a polyacrylic acid / sulfonic acid copolymer, a polysulfonic acid / acrylamide copolymer, and a polyacrylic acid / malonic acid copolymer It may be to include one, but is not limited thereto.

The anionic polymer including the carboxyl group (COOH) may be about 0.01 wt% to about 1 wt% of the polishing additive, but is not limited thereto. When the anionic polymer containing the carboxyl group (COOH) is less than about 0.01% by weight, the protection of the polished surface may be better performed during polishing, and when it is more than about 1% by weight, the polishing additive causes scratches. Easy to let

The nonionic polymer may be, for example, polyalkyl oxide, but is not limited thereto.

The nonionic polymer may include, for example, at least one selected from the group consisting of polyoxyethylene oxide (PEO), polyethylene oxide, and polypropylene oxide. However, the present invention is not limited thereto.

The nonionic polymer may be about 0.001 wt% to about 1 wt% of the polishing additive, but is not limited thereto. When the nonionic polymer is less than about 0.001% by weight, the polysilicon film stop function may be lowered. When the nonionic polymer is more than about 1% by weight, the hydrophobicity of the nonionic polymer may cause contamination, such as reattachment of particles after polishing. Can be.

Wherein the ammonium salt is selected from the group consisting of ammonium nitrate, ammonium formate, ammonium citrate, ammonium acetate, ammonium benzoate, ammonium bromide, ammonium carbonate, ammonium chloride, ammonium chromate, ammonium dichromate, ammonium oxalate, ammonium sulfamate, But are not limited to, those selected from the group consisting of ammonium sulfite, ammonium tartrate, ammonium tetrafluoroborate, ammonium thiocyanate, ammonium thiosulfate, ammonium ascorbate, and combinations thereof It is not.

The ammonium salt may be about 0.001 wt% to about 1 wt% of the polishing additive, but is not limited thereto. If the amount of the ammonium salt is less than about 00 wt%, it does not affect the stabilization of the slurry composition. If the ammonium salt is more than about 00 wt%, the electric double layer of the cerium oxide particles in the slurry composition is rapidly reduced to decrease the dispersion stability .

The organic acid may be selected from, for example, picolinic acid, nicotinic acid, isonicotinic acid, fusaric acid, dinicotinic acid, A compound selected from the group consisting of dipiconilic acid, lutidinic acid, quinolinic acid, glutamic acid, alanine, glycine, cystine, histidine, asparagine, but are not limited to, asparagine, guanidine, hydrazine, ethylenediamine, formic acid, acetic acid, benzoic acid, oxalic acid, succinic acid, Malic acid, maleic acid, malonic acid, citric acid, lactic acid, tricarballyic acid, tartaric acid, aspartic acid, aspartic acid, glutaric acid, adipic acid, suberic acid and fumaric acid, But is not limited to, at least one selected from the group consisting of phthalic acid, pyridinecarboxylic acid, and salts thereof.

The organic acid may be from about 10% to about 90% by weight of the polishing additive, but is not limited thereto. Less than about 10 weight percent can exhibit lower polishing characteristics, and greater than about 90 weight percent can increase substrate surface defects.

The dispersant may be one containing at least one amine group and at least one carboxyl group, but is not limited thereto.

The dispersant is selected from the group consisting of, for example, serine, glutamine, betaine, proline, pyroglutamic acid and amino butyric acid But it is not limited thereto. The serine may be, for example, L-serine, D-serine or DL-serine, but is not limited thereto.

The dispersant may be about 0.01 wt% to about 5 wt% of the polishing additive, but is not limited thereto. When the content of the dispersant is less than about 0.01% by weight, the slurry is less adsorbed on the polishing surface, thereby reducing the polishing rate. When the content of the initial step removal dispersant exceeds about 5% by weight, the excess dispersant Dosing decreases dispersion stability resulting in coagulation which results in micro scratches and defects.

The pH adjusting agent may serve to adjust the pH of the polishing additive to adjust the degree of dispersion of the coated abrasive particles. The pH adjusting agent may be, for example, ammonia, ammonium methyl propanol (AMP), tetra methyl ammonium hydroxide (TMAH), potassium hydroxide, sodium hydroxide, magnesium hydroxide, rubidium hydroxide, cesium hydroxide, sodium bicarbonate, sodium carbonate, triethanolamine, Tromethamine, niacinamide, nitric acid, sulfuric acid, phosphoric acid, hydrochloric acid, acetic acid, citric acid, glutaric acid, glutic acid, formic acid, lactic acid, malic acid, malonic acid, maleic acid, oxalic acid, phthalic acid, succinic acid, tartaric acid and combinations thereof It may be to include one selected from the group consisting of, but is not limited thereto.

The pH adjusting agent is to adjust the pH of the polishing additive to control the degree of dispersion of the coated abrasive particles, but may be about 0.01% to about 1% by weight of the polishing additive, but is not limited thereto.

The fourth aspect of the present invention can provide a method of polishing a substrate using the polishing slurry according to the second aspect of the present invention.

While supplying the polishing slurry of the present invention between the polishing film on the substrate and the polishing pad of the polishing apparatus for polishing the substrate, the polishing film can be polished by relatively moving while the polishing film is in contact with the polishing pad. have.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the equivalents of the claims, as well as the claims.

Claims (10)

A method for producing cerium oxide particles, wherein the cerium oxide particles are formed under supercritical or subcritical conditions.
The method of claim 1,
Wherein the supercritical or subcritical condition has a reaction temperature of 250 DEG C to 600 DEG C and a reaction pressure of 50 bar to 500 bar.
The method of claim 1,
The supercritical or subcritical condition uses at least one selected from the group consisting of supercritical or subcritical carbon dioxide, supercritical or subcritical alkanes, supercritical water or subcritical water, and supercritical or subcritical alcohols. Method for producing phosphorus and cerium oxide particles.
The method of claim 1,
Preparing a cerium oxide-containing solution by mixing a metal salt aqueous solution including a supercritical or subcritical fluid and a cerium salt;
Introducing the cerium oxide-containing solution into a reactor to react under supercritical or subcritical conditions to form cerium oxide particles; And
Separating and recovering the cerium oxide particles from the solution containing the cerium oxide particles;
A method for producing the cerium oxide particles comprising a.
5. The method of claim 4,
Wherein the cerium salt comprises at least any one selected from the group consisting of nitrate, sulfate, chloride, carbonate, acetate and phosphate of cerium.
5. The method of claim 4,
The metal salt aqueous solution, Zn, Co, Ni, Fe, Al, Ti, Ba and Mn, further comprising a salt of at least one metal selected from the group consisting of, cerium oxide particles production method.
Cerium oxide particles prepared by the method of any one of claims 1 to 6.
The method of claim 7, wherein
Wherein the average particle diameter of the secondary particles of the cerium oxide is 10 nm to 0.5 占 퐉.
Cerium oxide particles of claim 7;
Abrasive additives; And
Dispersing agent;
≪ / RTI >
The method of claim 9,
The polishing additive, at least one selected from the group consisting of an anionic polymer, a nonionic polymer, an ammonium salt, an organic acid and a pH adjusting agent containing a carboxyl group (COOH), polishing slurry.

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