KR20170004462A - Slurry comprising for sti polishing - Google Patents

Abstract

The present invention relates to a slurry composition for STI polishing having excellent polishing selectivity of a silicon oxide film and a silicon nitride film. According to an embodiment of the present invention, the slurry composition for STI polishing comprises: a polishing liquid including cerium oxide polishing particles manufactured under supercritical or subcritical conditions, and a dispersing agent; and a polymer additive including a sulfonic group.

Description

SLURRY COMPRISING FOR STI POLISHING [0002]

The present invention relates to a slurry composition for STI polishing.

In general, the shallow trench isolation chemical mechanical planarization (STI CMP) process controls the selectivity ratio of the silicon oxide film and the silicon nitride film to CMP. A polymer capable of selectively adsorbing to the silicon nitride film is used for the selectivity between the films. STI CMP generally proceeds at a pH of about 5 because the zeta potential of the surface of the silicon oxide film and silicon nitride film is opposite in the vicinity of pH 5. At around pH 5, the silicon nitride film has a cationic charge. Using this property, a polymer containing a carboxyl group having anionic charge is used. By using an anionic polymer containing such a carboxyl group as a passivation agent, the polishing of the silicon nitride film is prevented from proceeding at the time of polishing. It is a general STI CMP process to prevent the polishing process from proceeding after the silicon nitride film is exposed through the selection ratio of the high silicon oxide film and the silicon nitride film. However, as the silicon oxide film of the STI structure becomes more soft, defects and scratches in the silicon oxide film are more difficult to control. Accordingly, new particles and a new STI polishing slurry composition are needed to solve these problems.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a silicon oxide film having excellent shallow trench isolation (STI) And an excellent polishing selectivity between the silicon oxide film and the silicon nitride film.

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.

According to an embodiment of the present invention, there is provided an abrasive comprising: a polishing liquid comprising cerium oxide abrasive particles and a dispersant prepared under supercritical or subcritical conditions; And a polymer additive comprising a sulfone group. The present invention also provides a slurry composition for STI polishing.

The Ce ^{3 +} content of the surface of the cerium oxide abrasive grains may be 10% to 60%.

The average particle diameter of the cerium oxide abrasive grains may be 1 nm to 50 nm.

The cerium oxide abrasive grains may be 0.1 wt% to 20 wt% of the STI polishing slurry composition.

The dispersing agent may be at least one selected from the group consisting of polyacrylic acid, polyacrylic acid ammonium salt, polymethacrylic acid, polymethacrylic acid ammonium salt, polyacrylic maleic acid, carboxylic acid, carboxylate, sulphonic ester, sulphonic ester salt, sulphonic acid, And an anionic polymer comprising at least one selected from the group consisting of an ester and a phosphoric ester salt. The dispersant may be 0.01% by weight to 10% by weight of the STI polishing slurry composition.

The sulfone group-containing polymer additive may be selected from the group consisting of polystyrene sulfonate (PSS), benzene sulfonate, C _1-4 alkyl benzene sulfonate, di-C _1-4 alkyl benzene sulfonate, C _5-10 alkane sulfonate, A salt thereof, and a salt thereof.

The sulfone group-containing polymer additive may be 0.1 wt% to 5 wt% of the STI polishing slurry composition.

The pH of the sulfone group-containing polymer additive may be 3 to 6.

The slurry composition for STI polishing according to an embodiment of the present invention may contain at least one of ammonia, potassium hydroxide, sodium hydroxide, magnesium hydroxide, rubidium hydroxide, cesium hydroxide, sodium hydrogen carbonate, sodium carbonate, triethanolamine, tromethamine, But are not limited to, sulfuric acid, phosphoric acid, hydrochloric acid, acetic acid, citric acid, glutaric acid, gluconic acid, formic acid, lactic acid, malic acid, malonic acid, maleic acid, oxalic acid, phthalic acid, succinic acid, tartaric acid, ammonium methyl propanol (AMP) ), And the pH adjusting agent may be 0.01 wt% to 1 wt% of the STI polishing slurry composition.

The pH of the STI polishing slurry composition may be 4 to 8.

The slurry composition for STI polishing according to an embodiment of the present invention may have a polishing selectivity ratio of silicon nitride film to silicon oxide film in a shallow trench isolation (STI) process of 10: 1 to 150: 1.

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.

The supercritical or subcritical condition may be at least one selected from the group consisting of supercritical or subcritical carbon dioxide, supercritical or subcritical alkane, supercritical water or subcritical, and supercritical or subcritical alcohol Lt; / RTI >

Wherein the cerium oxide abrasive grains are prepared by mixing an aqueous metal salt solution containing supercritical or subcritical fluid and a cerium salt to prepare a cerium oxide-containing solution; Introducing the cerium oxide-containing solution into a reactor and reacting under supercritical or subcritical conditions to form cerium oxide abrasive grains; Separating and recovering the cerium oxide abrasive particles from a solution containing the cerium oxide abrasive grains; And heat treating the recovered cerium oxide abrasive grains.

The cerium salt may be at least one selected from the group consisting of cerium nitrate, ammonium nitrate, sulfate, chloride, carbonate, acetate and phosphate.

The aqueous metal salt solution may further comprise a salt of at least one metal selected from the group consisting of Zn, Co, Ni, Fe, Al, Ti, Ba and Mn.

The heat treatment may be performed at a temperature of 200 ° C to 900 ° C.

The STI polishing slurry composition of the present invention is excellent in crystallinity of abrasive grains by using cerium oxide abrasive grains synthesized under a supercritical or subcritical condition and is excellent in the surface of a silicon oxide film in a shallow trench isolation (STI) Defects, and scratches. In addition, by including a sulfone group-containing polymer additive as a passivation agent for the silicon nitride film, it is possible to obtain an excellent polishing selectivity between the silicon oxide film and the silicon nitride film.

FIG. 1 shows the SiO ₂ polishing rate and the Si ₃ N ₄ polishing rate using the slurry composition according to Example 1 of the present invention and Comparative Examples 1 to 4.
2 shows the SiO ₂ polishing rate and the Si ₃ N ₄ polishing rate using the slurry composition according to Example 1, Example 2, and Comparative Example 1 of the present invention.
FIG. 3 shows XPS analysis results of cerium oxide particles prepared under supercritical or subcritical conditions according to 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 these terms should be based on the contents throughout this specification. Like reference symbols in the drawings denote like elements.

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.

Hereinafter, the STI polishing slurry composition of the present invention will be specifically described with reference to examples and drawings. However, the present invention is not limited to these embodiments and drawings.

According to an embodiment of the present invention, there is provided an abrasive comprising: a polishing liquid comprising cerium oxide abrasive particles and a dispersant prepared under supercritical or subcritical conditions; And a polymer additive comprising a sulfone group. The present invention also provides a slurry composition for STI polishing.

The STI polishing slurry composition according to an embodiment of the present invention is excellent in crystallinity of abrasive grains by using cerium oxide abrasive grains synthesized under supercritical or subcritical conditions and is used in a shallow trench isolation (STI) Surface defects and scratches of the silicon oxide film can be reduced. Further, by including a polymer additive containing a sulfone group, it is possible to suppress polishing of the nitride film and to have a good selectivity between the silicon oxide film and the silicon nitride film.

The cerium oxide abrasive grains may have a surface Ce ^{3 +} content of 10% to 60%, preferably 5% to 30%. When the Ce ^{3 +} content on the surface is less than 10%, it is difficult to secure the target amount of polishing, and when the Ce ^{3 +} content is more than 60%, it is difficult to secure the dispersibility of the slurry.

The Ce ^{3 +} content of the surface of the cerium oxide abrasive grains can be analyzed using XPS. For example, theta probe base system manufactured by Thermo Fisher Scientific Co can be used. The Ce ^{3 +} content of the surface of the cerium oxide abrasive grains can be calculated by the following formula (1).

[Chemical Formula 1]

Ce ^{3 +} content (%) = (Ce ^{3 +} peak area) / [(Ce ^{3 +} peak area) + (Ce ^{4 +} peak area)]

The average particle diameter of the cerium oxide abrasive grains may be 1 nm to 50 nm, preferably 5 nm to 20 nm, more preferably 7 nm to 15 nm, which is excellent in the crystallinity of the cerium oxide abrasive grains. If the cerium oxide abrasive grains are less than 1 nm, there is a problem that the polishing performance is poor and the selection ratio is difficult to implement. If the cerium oxide abrasive grains are more than 50 nm, it is difficult to control surface defects, scratches, polishing rate and selectivity.

The cerium oxide abrasive grains may be 0.1 wt% to 20 wt%, preferably 0.5 wt% to 10 wt%, and more preferably 1 wt% to 5 wt% of the STI polishing slurry composition . If the amount of the cerium oxide abrasive grains is less than 0.1% by weight, the polishing rate is lowered. If the amount of the cerium oxide abrasive grains is more than 20% by weight, defects due to cerium oxide abrasive grains may occur.

The dispersing agent is for dispersing cerium oxide abrasive grains. The dispersing agent is selected from the group consisting of polyacrylic acid, ammonium polyacrylate, polymethacrylic acid, polymethacrylic acid ammonium salt, polyacrylic maleic acid, carboxylic acid, carboxylic acid salt, sulphonic ester, , An anionic polymer containing at least one selected from the group consisting of sulfonic acid, sulfonic acid salt, phosphonic ester, and phosphonic ester salt.

The dispersant may be 0.01% by weight to 10% by weight, preferably 0.1% by weight to 5% by weight in the STI polishing slurry composition. If the amount of the dispersant is less than 0.01% by weight, the selectivity is lowered and the dispersibility becomes insufficient. If the dispersant is more than 10% by weight, the slurry composition reacts with the abrasive grains There is a problem that adsorption causes aggregation phenomenon and causes defects or scratches.

The sulfone group-containing polymer additive is to increase the polishing selectivity of the oxide film / nitride film by suppressing the polishing of the nitride film by adsorption to the nitride film during polishing. RSO ₃ H (where R is an aliphatic or aromatic hydrocarbon or an aliphatic or aromatic hydrocarbon (PSS), benzenesulfonate, C _1-4 alkylbenzenesulfonate, di-C _1-4 < / RTI >< RTI ID = 0.0 & Alkyl benzene sulfonate, C _5-10 alkane sulfonate, and salts thereof. The C _1-4 alkylbenzenesulfonate may be, for example, toluene sulfonate, cumene sulfonate, and the di-C _1-4 alkylbenzenesulfonate may be, for example, xylene sulfonate, It can be Nate. They may also be sodium, lithium, calcium, potassium and ammonium salts thereof.

The pH of the sulfone group-containing polymer additive may be 3 to 6.

The sulfone group-containing polymer additive may be 0.1% by weight to 5% by weight, preferably 0.5% by weight to 3% by weight in the STI polishing slurry composition. When the sulfone group-containing polymer additive is less than 0.1 wt%, passivation of the silicon nitride film does not occur, and there is a concern that the cerium oxide abrasive grains are agglomerated. When the addition amount exceeds 5 wt%, the polishing performance of the silicon oxide film is deteriorated So that the polishing selectivity with the nitride film decreases.

The slurry composition for STI polishing according to an embodiment of the present invention may contain at least one of ammonia, potassium hydroxide, sodium hydroxide, magnesium hydroxide, rubidium hydroxide, cesium hydroxide, sodium hydrogen carbonate, sodium carbonate, triethanolamine, tromethamine, But are not limited to, sulfuric acid, phosphoric acid, hydrochloric acid, acetic acid, citric acid, glutaric acid, gluconic acid, formic acid, lactic acid, malic acid, malonic acid, maleic acid, oxalic acid, phthalic acid, succinic acid, tartaric acid, ammonium methyl propanol (AMP) And at least one pH adjusting agent selected from the group consisting of pH adjusting agents. The pH adjusting agent may control the dispersion degree of the coated abrasive grains by adjusting the pH of the STI polishing slurry composition.

The pH adjusting agent may be 0.01 to 1% by weight, preferably 0.1 to 0.5% by weight based on the STI polishing slurry composition so that the pH of the STI polishing slurry composition ranges from 4 to 8 .

The slurry composition for STI polishing according to an embodiment of the present invention may have a polishing selectivity ratio of silicon nitride film to silicon oxide film in a shallow trench isolation (STI) process of 10: 1 to 150: 1.

The cerium oxide abrasive grains according to an embodiment of the present invention are prepared under supercritical or subcritical conditions and are prepared by mixing an aqueous metal salt solution containing a supercritical fluid or a subcritical fluid and a cerium salt to prepare a cerium oxide- ; Introducing the cerium oxide-containing solution into a reactor and reacting under supercritical or subcritical conditions to form cerium oxide abrasive grains; Separating and recovering the cerium oxide abrasive particles from a solution containing the cerium oxide abrasive grains; And heat treating the recovered cerium oxide abrasive grains.

The cerium oxide abrasive grains may be prepared by first mixing a metal salt aqueous solution containing a supercritical fluid and a cerium salt to prepare a cerium oxide-containing solution.

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

The cerium salt may be at least one selected from the group consisting of cerium nitrate, ammonium nitrate, sulfate, chloride, carbonate, acetate and phosphate.

The aqueous metal salt solution may further comprise a salt of at least one metal selected from the group consisting of Zn, Co, Ni, Fe, Al, Ti, Ba and Mn.

The cerium oxide-containing solution may then be introduced into a reactor and reacted under supercritical conditions to form cerium oxide abrasive grains. 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. Cerium oxide abrasive grain formation can be performed under 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 abrasive particles to be produced is increased, the particle size distribution is widened, and the crystallinity is decreased. Or when the reaction pressure exceeds about 500 bar, the high temperature and high pressure must be maintained, resulting in low economic efficiency.

The reaction time for producing the cerium oxide abrasive particles of the present invention may be from several seconds to one hour, preferably from several seconds to 30 minutes. When the reaction time is not sufficient, there is a problem that the crystallinity is decreased. When the reaction time is too long, the size of the nanoparticles is increased and the particle size distribution is widened.

The supercritical or subcritical condition may be at least one selected from the group consisting of supercritical or subcritical carbon dioxide, supercritical or subcritical alkane, supercritical water or subcritical, and supercritical or subcritical alcohol And can be selectively used depending on the type of reaction, kind of product, and reaction conditions, but the present invention is not limited thereto. Among them, examples of the supercritical or subcritical alkane include an alkane having 1 to 10 carbon atoms.

Additionally, the method may further comprise cooling the solution comprising the cerium oxide abrasive particles after the step of reacting the cerium oxide-containing solution to form cerium oxide abrasive grains. In the cooling step, general methods such as a heat exchanger and a cooler can be used.

The cerium oxide abrasive grains can then be separated and recovered from a solution containing the cerium oxide abrasive grains. In the step of separating and recovering the cerium oxide abrasive grains, a general method of separating the solid from a liquid such as filtration using a filter having an appropriate pore size or using a centrifugal separator can be used.

Additionally, after the step of separating and recovering the cerium oxide abrasive grains, washing and drying of the cerium oxide abrasive grains may be further included. In the washing step, for example, general methods such as water or organic solvent washing can be used. In the drying step, for example, vacuum drying, oven drying, freeze drying and the like can be used.

The cerium oxide abrasive grains can then be heat-treated. The heat treatment may be performed at a temperature of 200 ° C to 900 ° C. If the heat treatment temperature is less than 200 ° C, crystal water and impurities can not be removed and it is difficult to expect a heat treatment effect. If the heat treatment temperature exceeds 900 ° C, there is a problem of grain growth.

The cerium oxide abrasive grains synthesized under the supercritical or subcritical conditions of the present invention can easily control the crystal structure, shape and size, and are superior to the cerium oxide abrasive grains prepared by the liquid phase method with excellent abrasive properties such as scratches and defect reduction Lt; / RTI > Further, since the density can be increased to the theoretical density without further grain growth through heat treatment, the crystallinity is excellent and the polishing rate is high.

The cerium oxide abrasive grains synthesized in supercritical or subcritical conditions of the present invention can reduce the surface defects and scratches of the silicon oxide film in the STI process, It is possible to have an excellent polishing selectivity between the silicon oxide film and the silicon nitride film.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

[Example 1]

A cerium oxide-containing solution was prepared by mixing an aqueous solution of cerium nitrate containing water and a cerium salt. Thereafter, the cerium oxide-containing solution was introduced into a reactor in a supercritical state and reacted at a reaction temperature of 350 DEG C and a reaction pressure of 250 bar to form abrasive grains. Thereafter, the cerium oxide particles were produced through a collection and filtration process.

4 wt% of 10 nm cerium oxide abrasive grains synthesized by supercritical hydrothermal synthesis, 4 wt% of polymethacrylic acid as a dispersant, and 4 wt% of cerium oxide abrasive grains were mixed to prepare a polishing solution.

0.3 wt% of polystyrene sulfonate (PSS) as a polymer additive was adjusted to pH 5.

The polishing solution and the polymer additive were mixed at a ratio of 1: 1 to prepare a slurry composition for STI polishing.

[Example 2]

A slurry composition for STI polishing was prepared in the same manner as in Example 1 except that 0.1 wt% of polystyrene sulfonate (PSS) was added.

[Comparative Example 1]

A slurry composition was prepared in the same manner as in Example 1, except that polystyrene sulfonate (PSS) was not added.

[Comparative Example 2]

A slurry composition was prepared in the same manner as in Example 1, except that 0.3 wt% of polyacrylic acid (PAA) 2k was added instead of polystyrene sulfonate (PSS).

[Comparative Example 3]

A slurry composition was prepared in the same manner as in Example 1 except that 0.3 wt% of polyacrylic acid (PAA) 5k was added instead of polystyrene sulfonate (PSS).

[Comparative Example 4]

A slurry composition was prepared in the same manner as in Example 1, except that 0.3 wt% of polyacrylic acid (PAA) 10k was added instead of polystyrene sulfonate (PSS).

The slurry compositions containing the cerium oxide abrasive grains of Examples 1 and 2 and Comparative Examples 1 to 3 were polished under the following polishing conditions.

[Polishing condition]

1. Grinder: CETR CP-4

2. Pad: IC-1010 (Rohm & Hass)

3. Polishing time: 60 s

Table RPM (Table RPM): 70 rpm

5. Flow rate: 100 ml / min

6. Wafers used: 6 cm x 6 cm coupon wafer (SiO ₂ , Si ₃ N ₄ )

7. Pressure: 4.0 psi

Table 1 below shows the SiO ₂ polishing rate and the Si ₃ N ₄ polishing rate according to the content of the polymer additive using the slurry composition according to Examples 1 and 2 and Comparative Examples 1 to 4.

Polymer
additive content
(weight%) SiO ₂ polishing rate
(Å / min) Si ₃ N ₄ removal rate
(Å / min) Selection ratio Example 1 PSS 0.3 447 7 63.9 Example 2 PSS 0.1 458 22 20.8 Comparative Example 1 - - 457 58 7.9 Comparative Example 2 PAA 2k 0.3 49 24 2.0 Comparative Example 3 PAA 5k 0.3 38 37 1.0 Comparative Example 4 PAA 10k 0.3 34 57 0.6

FIG. 1 shows the SiO ₂ polishing rate and the Si ₃ N ₄ polishing rate using the slurry composition according to Example 1 of the present invention and Comparative Examples 1 to 4. Referring to Table 1 and FIG. 1, when polishing was carried out using a slurry composition comprising polyacrylic acid (PAA) according to Comparative Examples 1 to 4, the active sites on the surface of the supercritical cerium oxide abrasive particles were blocked without, the use of a slurry composition comprising a polystyrene sulfonate (PSS) of the first embodiment, reduction in SiO ₂ Si ₃ N ₄ removal rate It can be seen that passivation of the film is possible.

2 shows the SiO ₂ polishing rate and the Si ₃ N ₄ polishing rate using the slurry composition according to Example 1, Example 2, and Comparative Example 1 of the present invention. Referring to Table 1 and FIG. 2, the SiO ₂ film of Examples 1 and 2, which is a slurry composition containing polystyrene sulfonate (PSS) rather than the polishing selectivity of Comparative Example 1, which is a slurry composition containing no polystyrene sulfonate (PSS) It can be seen that the polishing selectivity ratio of the comparative Si ₃ N ₄ film is high. In addition, it can be seen that the polishing selectivity ratio of the Si ₃ N ₄ film to the SiO ₂ film of Example 1, which is 0.3 wt%, is higher than that of Example 2 where the polystyrene sulfonate (PSS) content is 0.1 wt%.

FIG. 3 shows XPS analysis results of cerium oxide particles prepared under supercritical or subcritical conditions according to the present invention.

Peak: 883.3 886.9 (Ce ³⁺ ) 889.9 899.5 902 905.2 (Ce ³⁺ ) 908.5 917.9

Example 1 in the supercritical or sub-results from the XPS analysis results of the cerium oxide particles produced in the critical conditions by the formula described in the above calculation the Ce ^{3 +} content, it can be seen that the Ce ^{3 +} content is 16.8% . It can be seen that Ce ^{3 +} is a reactive site in the cerium oxide particles, and thus the polishing amount can be increased.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. 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 (17)

A polishing liquid comprising cerium oxide abrasive particles and a dispersant prepared under supercritical or subcritical conditions; And
Polymeric additives including sulfone groups;
By weight based on the total weight of the slurry.
The method according to claim 1,
The Ce ^{3 +} content of the cerium oxide abrasive grain surface is from 10% to 60%, STI polishing slurry composition.
The method according to claim 1,
Wherein the cerium oxide abrasive grains have an average particle diameter of 1 nm to 50 nm.
The method according to claim 1,
Wherein the cerium oxide abrasive grains are 0.1 wt% to 20 wt% of the STI polishing slurry composition.
The method according to claim 1,
The dispersing agent may be at least one selected from the group consisting of polyacrylic acid, polyacrylic acid ammonium salt, polymethacrylic acid, polymethacrylic acid ammonium salt, polyacrylic maleic acid, carboxylic acid, carboxylate, sulphonic ester, sulphonic ester salt, sulphonic acid, And an anionic polymer comprising at least one selected from the group consisting of esters and phosphonic ester salts,
Wherein the dispersant is 0.01 wt% to 10 wt% of the STI polishing slurry composition.
The method according to claim 1,
The sulfone group-containing polymer additive may be selected from the group consisting of polystyrene sulfonate (PSS), benzene sulfonate, C _1-4 alkyl benzene sulfonate, di-C _1-4 alkyl benzene sulfonate, C _5-10 alkane sulfonate, And at least one selected from the group consisting of a metal salt and a metal salt.
The method according to claim 1,
Wherein the sulfone group-containing polymer additive is 0.1 wt% to 5 wt% of the slurry composition for STI polishing.
The method according to claim 1,
Wherein the sulfone group-containing polymer additive has a pH of 3 to 6.
The method according to claim 1,
Sodium hydroxide, sodium carbonate, triethanolamine, tromethamine, niacinamide, nitric acid, sulfuric acid, phosphoric acid, hydrochloric acid, acetic acid, citric acid, glutaric acid, glutaric acid, At least one pH adjusting agent selected from the group consisting of cholic acid, formic acid, lactic acid, malic acid, malonic acid, maleic acid, oxalic acid, phthalic acid, succinic acid, tartaric acid, ammonium methyl propanol (AMP) and tetramethyl ammonium hydroxide (TMAH);
Further comprising:
Wherein the pH adjusting agent is 0.01 wt% to 1 wt% of the STI polishing slurry composition.
The method according to claim 1,
Wherein the STI polishing slurry composition has a pH of from 4 to 8.
The method according to claim 1,
Wherein the polishing selectivity ratio of the silicon nitride film to the silicon oxide film in the shallow trench isolation (STI) process is 10: 1 to 150: 1.
The method according to 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 according to claim 1,
The supercritical or subcritical condition may be at least one selected from the group consisting of supercritical or subcritical carbon dioxide, supercritical or subcritical alkane, supercritical water or subcritical, and supercritical or subcritical alcohol By weight based on the total weight of the slurry composition.
The method according to claim 1,
The cerium oxide abrasive grains contain,
Mixing an aqueous metal salt solution comprising a supercritical or subcritical fluid and a cerium salt to produce a cerium oxide-containing solution;
Introducing the cerium oxide-containing solution into a reactor and reacting under supercritical or subcritical conditions to form cerium oxide abrasive grains;
Separating and recovering the cerium oxide abrasive particles from a solution containing the cerium oxide abrasive grains; And
Heat treating the recovered cerium oxide abrasive grains;
By weight based on the total weight of the slurry.
15. The method of claim 14,
Wherein the cerium salt comprises at least any one selected from the group consisting of cerium nitrate, ammonium nitrate, sulfate, chloride, carbonate, acetate and phosphate.
15. The method of claim 14,
Wherein the metal salt aqueous solution further comprises a salt of at least one metal selected from the group consisting of Zn, Co, Ni, Fe, Al, Ti, Ba and Mn.
15. The method of claim 14,
Wherein the heat treatment is performed at a temperature of 200 ° C to 900 ° C.

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