KR102619857B1 - Cmp slurry composition for polishing tungsten and method for polishing tungsten using the same - Google Patents

Abstract

A CMP slurry composition for polishing tungsten including a solvent and abrasive particles first modified with amino silane and then secondarily modified with alkyl silane, and a tungsten polishing method using the same are disclosed.

Description

CMP slurry composition for tungsten polishing and tungsten polishing method using the same {CMP SLURRY COMPOSITION FOR POLISHING TUNGSTEN AND METHOD FOR POLISHING TUNGSTEN USING THE SAME}

It relates to a CMP slurry composition for tungsten polishing and a tungsten polishing method using the same. More specifically, it relates to a tungsten polishing method that has a high polishing rate for a tungsten film, a high polishing selectivity of the tungsten film to the oxide film, and can reduce scratches generated during polishing. It relates to a CMP slurry composition and a tungsten polishing method using the same.

Chemical mechanical polishing (CMP) compositions and methods for polishing (or planarizing) the surface of a substrate are well known in the art. A polishing composition for polishing a metal layer (eg, tungsten) on a semiconductor substrate may include abrasive particles suspended in an aqueous solution and a chemical accelerator, such as an oxidizing agent, a catalyst, etc.

The process of polishing a metal layer with a CMP composition includes the steps of polishing only the initial metal layer, polishing the metal layer and barrier layer, and polishing the metal, barrier layer, and oxide film.

An object of the present invention is to provide a CMP slurry composition for tungsten polishing that has a high polishing rate for a tungsten film.

Another object of the present invention is to provide a CMP slurry composition for tungsten polishing that has a high polishing selectivity of the tungsten film to the oxide film.

Another object of the present invention is to provide a CMP slurry composition for tungsten polishing that can reduce scratches occurring during polishing.

Another object of the present invention is to provide a tungsten polishing method using the CMP slurry composition for tungsten polishing.

1. According to one aspect, a CMP slurry composition for tungsten polishing is provided. The composition includes a solvent; and abrasive particles first modified with amino silane and then secondarily modified with alkyl silane; may include.

2. In 1 above, the amino silane may include a compound of formula 1 below, a cation derived from a compound of formula 1 below, or a salt of a compound of formula 1 below:

<Formula 1>

H ₂ N-(CH ₂ ) _n1 -Si(OR ¹ ) ₃

In Formula 1, n1 is selected from an integer of 1 to 12, and R ¹ is selected from hydrogen and a C ₁ -C ₄ alkyl group.

3. In 2 above, in Formula 1, n1 is 3, and R ¹ may be an ethyl group.

4. In any one of 1 to 3 above, the alkyl silane may include a compound of the following formula (2):

<Formula 2>

H ₃ C-(CH ₂ ) _n2 -Si(OR ² ) ₃

In Formula 2, n2 is selected from an integer of 1 to 12, and R ² is selected from hydrogen and a C ₁ -C ₄ alkyl group.

5. In 4 above, in Formula 2, n2 is selected from an integer of 5 to 7, and R ² may be an ethyl group.

6. In any one of 1 to 5 above, amino silane-derived groups and alkyl silane-derived groups may be bonded to the abrasive particles at a molar ratio of 9:1 to 1:9.

7. In any one of 1 to 6 above, the abrasive particles may include silica.

8. In any one of 1 to 7 above, the average particle diameter (D ₅₀ ) of the abrasive particles may be 10 to 200 nm.

9. In any one of items 1 to 8, the abrasive particles may be included in an amount of 0.001 to 20% by weight in the composition.

10. In any one of 1 to 9 above, the composition may further include one or more of an oxidizing agent, a catalyst, and an organic acid.

11. In item 10, the oxidizing agent may be included in an amount of 0.01 to 20% by weight, the catalyst may be included in an amount of 0.001 to 10% by weight, and the organic acid may be included in an amount of 0.001 to 20% by weight in the composition.

12. In any one of 1 to 11 above, the composition may have a pH of 1 to 5.

13. According to another aspect, a tungsten polishing method is provided. The method may include polishing tungsten using the CMP slurry composition for polishing tungsten of any one of 1 to 12 above.

The present invention has the effect of providing a CMP slurry composition for tungsten polishing that has a high polishing rate for a tungsten film, a high polishing selectivity of a tungsten film to an oxide film, and can reduce scratches generated during polishing, and a tungsten polishing method using the same. .

In this specification, singular expressions include plural expressions, unless the context clearly dictates otherwise.

In this specification, terms such as include or have mean that the features or components described in the specification exist, and do not exclude in advance the possibility of adding one or more other features or components.

When interpreting a component, it is interpreted to include the margin of error even if there is no separate explicit description.

In the present specification, in “a to b” indicating a numerical range, “to” is defined as ≥a and ≤b.

The inventor of the present invention, in a CMP slurry composition for tungsten polishing containing a solvent and an abrasive, uses abrasive particles that are first modified with amino silane as an abrasive and then secondarily modified with alkyl silane, thereby increasing the polishing rate for the tungsten film. The present invention was completed after confirming that the polishing selectivity of the tungsten film to the oxide film can be increased and scratches generated during polishing can be reduced.

A CMP slurry composition for tungsten polishing (hereinafter, also referred to as 'CMP slurry composition') according to an embodiment of the present invention includes a solvent; and abrasive particles first modified with amino silane and then secondarily modified with alkyl silane; may include.

Hereinafter, the components of the CMP slurry composition according to one embodiment of the present invention will be described in detail.

Solvents can reduce friction when polishing a tungsten film with an abrasive. The solvent may be a polar solvent, a non-polar solvent, or a combination thereof. For example, water (e.g., ultrapure water, deionized water, etc.), organic amine, organic alcohol, organic alcoholamine, organic ether, organic ketone, etc. can be used According to one embodiment, the solvent may be ultrapure water or deionized water, but is not limited thereto. The solvent may be included in the remaining amount in the CMP slurry composition.

The abrasive particles can polish the tungsten film at a high polishing rate. The abrasive particles may be, for example, metal or non-metal oxide abrasive particles, and may include, for example, one or more of silica, alumina, ceria, titania, and zirconia. According to one embodiment, the abrasive particles may be silica (eg, colloidal silica), but are not limited thereto.

The abrasive particles may be first modified with amino silane and then secondarily modified with alkyl silane. When abrasive particles are primarily modified with amino silane, the surface of the primary modified abrasive particles becomes positively charged in the acidic region, and the tungsten film is polished at a high polishing rate through electrostatic attraction with the negatively charged tungsten film. It can be. However, if the electrostatic attraction is too strong, many scratches may occur during polishing. By secondarily modifying the primary modified abrasive particles with alkyl silane, the distance between the abrasive particles and the tungsten film is increased to alleviate the electrostatic attraction during polishing. Scratches that occur can be reduced.

Abrasive particles that have been first modified with amino silane and then secondarily modified with alkyl silane are added to the unmodified abrasive particles with the amino silane to be modified, reacted for a predetermined time, and then added to the abrasive particles modified with amino silane. It can be prepared by adding an alkyl silane and reacting for a predetermined period of time.

According to one embodiment, the amino silane may include a compound of Formula 1 below, a cation derived from a compound of Formula 1 below, or a salt of a compound of Formula 1 below.

<Formula 1>

H ₂ N-(CH ₂ ) _n1 -Si(OR ¹ ) ₃

Here, 'cation derived from the compound of Formula 1' may mean H ₃ N ⁺ -(CH ₂ ) _n1 -Si(OR ¹ ) ₃ . Meanwhile, in the 'salt of the compound of Formula 1', the cation is H ₃ N ⁺ -(CH ₂ ) _n1 -Si(OR ¹ ) ₃ , and the anion is, for example, a halogen anion (e.g. F ^- , Cl ^- , Br) -, I ^- ); Organic acid anions such as carbonate anions (e.g. CO ₃ ^2- , HCO ₃ ^- ), acetic acid anions (CH ₃ COO ^- ), and citric acid anions (HOC(COO ^- )(CH ₂ COO ^- ) ₂ ); and/or nitrogen-containing anions (e.g. NO ₃ ^- , NO ₂ ^- ); phosphorus containing anions (e.g. PO ₄ ^3- , HPO ₄ ^2- , H ₂ PO ₄ ^- ); sulfur-containing anions (e.g. SO ₄ ^2- , HSO ₄ ^- ); It may be an inorganic acid anion such as cyanide anion (CN ^- ).

In Formula 1, n1 refers to the number of *-CH ₂ -*' (where * and *' are bonding sites with neighboring atoms), and may be selected from an integer of 1 to 12. n1 may be selected from an integer of, for example, 1 to 5, or for example, 2 to 4. According to one implementation, n1 may be 3, but is not limited thereto.

In Formula 1, R ¹ may be selected from hydrogen and C ₁ -C ₄ alkyl group. Within the above range, there may be a difference in hydrolysis rate due to steric hindrance, but it is not limited thereto. R ¹ may be selected from, for example, C ₁ -C ₂ alkyl groups. According to one embodiment, R ¹ may be an ethyl group, but is not limited thereto.

According to another embodiment, the amino silane may include aminopropyltriethoxysilane.

According to one embodiment, the alkyl silane may include a compound of Formula 2 below.

<Formula 2>

H ₃ C-(CH ₂ ) _n2 -Si(OR ² ) ₃

In Formula 2, n2 refers to the number of *-CH ₂ -*' (where * and *' are bonding sites with neighboring atoms), and may be selected from an integer of 1 to 12. Within the above range, the effect of lowering the surface strength may be achieved by using a soft organic silane, but the effect is not limited thereto. n2 may be selected from, for example, an integer of 4 to 8, or, for example, an integer of 5 to 7, but is not limited thereto.

In Formula 2, R ² may be selected from hydrogen and C ₁ -C ₄ alkyl group. Within the above range, there may be a difference in hydrolysis rate due to steric hindrance, but it is not limited thereto. R ² may be selected from, for example, C ₁ -C ₂ alkyl groups. According to one embodiment, R ² may be an ethyl group, but is not limited thereto.

Abrasive particles that are first modified with amino silane and then secondarily modified with alkyl silane may include amino silane-derived groups and alkyl silane-derived groups on the surface of the abrasive particles as follows:

.

Therefore, according to one embodiment, amino silane-derived groups and alkyl silane-derived groups may be bonded to the surface of the abrasive particle at a molar ratio of 9:1 to 1:9. Within the above range, the tungsten film can be polished at a high polishing rate, the polishing selectivity of the tungsten film to the oxide film can be increased, and scratches generated during polishing can be reduced, but the present invention is not limited to this. For example, on the surface of the abrasive particle, amino silane derived groups and alkyl silane derived groups are present in a ratio of 9:1 to 1:1, for example 9:1 to 5:5, for another example 8:2 to 7:3. It may be combined in a molar ratio of .

Abrasive particles that are first modified with amino silane and then secondarily modified with alkyl silane are spherical or non-spherical particles, and the average particle diameter (D ₅₀ ) of the primary particles is, for example, 10 to 200 nm, for example, 20 nm. to 180 nm, for another example, 40 to 130 nm. Within the above range, the tungsten film can be polished at a high polishing rate, the polishing selectivity of the tungsten film to the oxide film can be increased, and scratches generated during polishing can be reduced, but the present invention is not limited to this. Here, 'average particle diameter (D ₅₀ )' refers to the normal particle size known to those skilled in the art, and refers to the particle size of the abrasive particles corresponding to 50% by volume when the abrasive particles are distributed in order from minimum to maximum based on volume. You can.

Abrasive particles that are first modified with amino silane and then secondarily modified with alkyl silane are included in the CMP slurry composition, for example, 0.001 to 20% by weight, for example, 0.01 to 10% by weight, for example, 0.05 to 5% by weight. % by weight, for example, 0.5 to 3% by weight. Within this range, the tungsten film can be polished at a high polishing rate, the polishing selectivity of the tungsten film to the oxide film can be increased, and the polishing selectivity of the tungsten film to the oxide film can be increased, and the amount generated during polishing can be reduced. Scratches can be reduced and the dispersion stability of the composition can be good, but it is not limited to this.

The CMP slurry composition may further include one or more of an oxidizing agent, a catalyst, and an organic acid in addition to a solvent and abrasive particles.

The oxidizing agent can oxidize the tungsten film to facilitate polishing of the tungsten film. Examples of oxidizing agents include inorganic percompounds, organic percompounds, bromic acid or its salts, nitric acid or its salts, chloric acid or its salts, chromic acid or its salts, iodic acid or its salts, iron or its salts, copper or its salts, and rare earths. Metal oxides, transition metal oxides, and potassium dichromate may be included, and these may be used alone or in a mixture of two or more types. Here, 'percompound' may mean a compound containing one or more peroxide groups (-O-O-) or containing an element in the highest oxidation state. According to one embodiment, the oxidizing agent may include a peroxide compound (eg, hydrogen peroxide, potassium periodide, calcium persulfate, potassium ferricyanide, etc.). According to another embodiment, the oxidizing agent may be hydrogen peroxide, but is not limited thereto.

The oxidizing agent may be included in the CMP slurry composition at, for example, 0.01 to 20% by weight, for example, 0.05 to 10% by weight, or for example, 0.1 to 5% by weight, and within the above range, the polishing rate of the tungsten film is adjusted. It can be improved, but it is not limited to this.

The catalyst can improve the polishing speed of the tungsten film, and examples thereof include iron ion compounds, iron ion complexes, and hydrates thereof.

The iron ion compound may include, for example, a compound containing iron trivalent cations. Compounds containing iron trivalent cations are not particularly limited as long as they are compounds in which the iron trivalent cation exists as a free cation in an aqueous solution, and examples of these include iron chloride (FeCl ₃ ), iron nitrate (Fe(NO ₃ ) ₃ ), and iron sulfate. (Fe ₂ (SO ₄ ) ₃ ) and the like, but are not limited thereto.

Iron ion complexes may include, for example, iron trivalent cation-containing complexes. Complex compounds containing iron trivalent cations are compounds formed by reacting iron trivalent cations with an organic or inorganic compound having at least one functional group from, for example, carboxylic acids, phosphoric acids, sulfuric acids, amino acids, and amines in an aqueous solution. may include. Examples of the organic or inorganic compounds include citrate, ammonium citrate, paratoluenesulfonic acid (pTSA), 1,3-propylenediaminetetraacetic acid (PDTA), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and nitrilotriacetic acid (NTA). , EDDS (ethylenediamine-N,N'-disuccinic acid), etc. Specific examples of iron trivalent cation-containing complexes include ferric citrate, ferric ammonium citrate, Fe(III)-pTSA, Fe(III)-PDTA, and Fe(III)-EDTA. It may be mentioned, but it is not limited to this.

A catalyst, for example, an iron ion compound, a complex of iron ions, or a hydrate thereof, may be present in an amount of, for example, 0.001 to 10% by weight, for example, 0.001 to 5% by weight, or another example, in the CMP slurry composition. It may be included at 0.001 to 1% by weight, for example, 0.001 to 0.5% by weight, and within this range, the polishing speed of the tungsten film can be improved, but is not limited thereto.

Organic acids can keep the pH of the CMP slurry composition stable. Examples of organic acids include carboxylic acids such as malonic acid, maleic acid, and malic acid, and glycine, isoleucine, leucine, phenylalanine, methionine, threonine, tryptophan, valine, alanine, arginine, cysteine, glutamine, histidine, proline, serine, tyrosine, and lysine. Amino acids can be mentioned.

The organic acid may be included in the CMP slurry composition at, for example, 0.001 to 20% by weight, for example, 0.01 to 10% by weight, for example, 0.01 to 5% by weight, or for example, 0.01 to 1% by weight. In the above range, the tungsten film can be polished at a high polishing rate, the polishing selectivity of the tungsten film to the oxide film can be increased, and scratches generated during polishing can be reduced, but is not limited to this.

The CMP slurry composition may have a pH of, for example, 1 to 5, or, for example, 2 to 4. In this range, oxidation of tungsten metal may easily occur and the polishing rate may not easily drop, but is not limited thereto. no.

The CMP slurry composition may further include a pH adjuster to adjust the pH.

The pH adjuster may include one or more inorganic acids, such as nitric acid, phosphoric acid, hydrochloric acid, and sulfuric acid, and an organic acid, such as an organic acid with a pK _a value of 6 or less, such as one or more types of acetic acid and phthalic acid. It can be included. The pH adjusting agent may include one or more of a base such as ammonia water, sodium hydroxide, potassium hydroxide, ammonium hydroxide, sodium carbonate, and potassium carbonate.

In addition to the ingredients described above, the CMP slurry composition may further include conventional additives such as biocides, surfactants, dispersants, modifiers, and surface active agents, if necessary. The additive may be included in the composition in an amount of, for example, 0.001 to 5% by weight, for example, 0.001 to 1% by weight, or for example, 0.001 to 0.5% by weight, and within this range, it does not affect the polishing rate. The additive effect can be realized without using the additive, but it is not limited to this.

According to another aspect, a tungsten polishing method is provided. The polishing method may include polishing tungsten using the above-described CMP slurry composition for polishing tungsten.

Hereinafter, the present invention will be described in more detail through examples. However, this is presented as a preferred example of the present invention, and should not be construed as limiting the present invention in any way.

Example

Preparation Example 1: Preparation of modified abrasive particles

Mix 40 g of silica (Nalco, DVSTS006) as abrasive particles and 1.0 g of aminopropyltriethoxysilane as amino silane in 60 g of deionized water, adjust the pH to 2 to 4 using HNO ₃ , and leave at 25°C for 72 hours. The abrasive particles were first modified by reacting for a while. After washing and drying the primary modified abrasive particles, 50 g of the primary modified abrasive particles and 1.0 g of hexyltriethoxysilane as an alkyl silane were mixed with 50 g of deionized water, and the pH was adjusted to 2 to 4 using HNO ₃ . Afterwards, the abrasive particles were secondary modified by reacting at 25° C. for 48 hours to prepare abrasive particles A. As a result of analyzing the abrasive particle A by NMR, amino silane-derived groups and alkyl silane-derived groups were bonded to the surface of the abrasive particle A at a molar ratio of 8:2.

Production example 2

Abrasive particles B were manufactured using the same method as Preparation Example 1, except that n-octyltriethoxysilane was used instead of hexyltriethoxysilane. On the surface of the abrasive particle B, amino silane-derived groups and alkyl silane-derived groups were bonded at a molar ratio of 7:3.

Production example 3

60 g of deionized water was mixed with 40 g of silica (Nalco, DVSTS006) as abrasive particles, 1.0 g of aminopropyltriethoxysilane as amino silane, and 1.0 g of hexyltriethoxysilane as alkyl silane, and the pH was adjusted to 2 using HNO ₃ . After adjusting to ~4, the abrasive particles were modified by reacting at 25°C for 96 hours to prepare abrasive particles C. On the surface of the abrasive grain C, amino silane-derived groups and alkyl silane-derived groups were bonded at a molar ratio of 2:8.

Production example 4

Mix 40 g of silica (Nalco, DVSTS006) as an abrasive particle and 1.0 g of hexyltriethoxysilane as an alkyl silane in 60 g of deionized water, adjust the pH to 2 to 4 using HNO ₃ , and leave at 25°C for 72 hours. The reaction was performed to first modify the abrasive particles. After washing and drying the primary modified abrasive particles, 50 g of primary modified abrasive particles and 1.0 g of aminopropyltriethoxysilane as amino silane were mixed with 50 g of deionized water, and the pH was adjusted to 2 to 4 using HNO ₃ . After adjusting, the abrasive particles were secondary modified by reacting at 25° C. for 48 hours to produce abrasive particles D. On the surface of the abrasive particle D, amino silane-derived groups and alkyl silane-derived groups were bonded at a molar ratio of 3:7.

Example 1: Preparation of CMP slurry composition

Based on the total weight of the CMP slurry composition, it contains 0.5% by weight of abrasive particles A as an abrasive, 0.03% by weight of iron (III) nitrate as a catalyst, 0.04% by weight of malonic acid and 0.03% by weight of glycine as an organic acid, and the remainder is deionized water as a solvent. A CMP slurry composition containing was prepared. The pH of the CMP slurry composition was adjusted to 2.5 using HNO ₃ , a pH adjuster. Afterwards, 4.0% by weight of hydrogen peroxide was added as an oxidizing agent.

Example 2

A CMP slurry composition was prepared using the same method as Example 1, except that abrasive particle B was used instead of abrasive particle A.

Comparative Example 1

A CMP slurry composition was prepared using the same method as Example 1, except that silica, an unmodified abrasive particle, was used instead of abrasive particle A.

Comparative Example 2

A CMP slurry composition was prepared using the same method as Example 1, except that abrasive particle C was used instead of abrasive particle A.

Comparative Example 3

A CMP slurry composition was prepared using the same method as Example 1, except that abrasive particle D was used instead of abrasive particle A.

After polishing evaluation was performed on the CMP slurry compositions prepared in the examples and comparative examples, the results are shown in Table 1 below.

(1) Polishing speed (unit: Å/min): Grind a wafer with tungsten deposited to a thickness of 6,000 Å or a silicon oxide wafer with a PETEOS deposited to a thickness of 20,000 Å using an IC1010 polishing pad on a Reflexion 300mm polisher at a head speed of 101 rpm and a platen speed of 100 rpm. , polishing was performed for 45 seconds under the conditions of polishing pressure of 2.5psi, retainer ring pressure of 8psi, and mixed solution flow rate of 250ml/min. The tungsten film polishing speed was obtained by converting the difference in film thickness before and after polishing from the electrical resistance value. The oxide film polishing speed was obtained by converting the difference in film thickness before and after polishing using an optical interference thickness meter (Reflectometer).

(2) Scratch (unit: ea/WF): After measuring defect inspection on a tungsten wafer polished under the same polishing process conditions as (1) above, confirming the coordinates of the defect location, separating the shape of the defect with a review SEM and calculating the number of scratches. observed.

Abrasive type tungsten film
polishing speed oxide film
polishing speed scratch Example 1 Abrasive grain A 4740 15 102 Example 2 Abrasive grain B 4259 26 263 Comparative Example 1 Unmodified Abrasive Grains 2500 144 407 Comparative Example 2 Abrasive grain C 2742 206 301 Comparative Example 3 Abrasive grain D 2622 148 295

As shown in Table 1, the composition including abrasive particles first modified with amino silane and then secondarily modified with alkyl silane, such as the composition of the present invention, has a polishing rate of the tungsten film and a polishing selectivity of the tungsten film to the oxide film. , scratches have all been improved.

So far, the present invention has been examined focusing on the embodiments. A person skilled in the art to which the present invention pertains will understand that the present invention can be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered from an illustrative rather than a restrictive perspective. The scope of the present invention is indicated in the claims rather than the foregoing description, and all differences within the equivalent scope should be construed as being included in the present invention.

Claims (13)

menstruum; and
Abrasive particles first modified with amino silane and then secondarily modified with alkyl silane; Including,
A CMP slurry composition for tungsten polishing, wherein amino silane-derived groups and alkyl silane-derived groups are bonded to the abrasive particles at a molar ratio of 9:1 to 1:1.
According to paragraph 1,
A CMP slurry composition for tungsten polishing, wherein the amino silane includes a compound of the following formula (1), a cation derived from the compound of the following formula (1), or a salt of a compound of the following formula (1):
<Formula 1>
H ₂ N-(CH ₂ ) _n1 -Si(OR ¹ ) ₃
In Formula 1, n1 is selected from an integer of 1 to 12, and R ¹ is selected from hydrogen and a C ₁ -C ₄ alkyl group.
According to paragraph 2,
In Formula 1, n1 is 3 and ^R1 is an ethyl group, a CMP slurry composition for polishing tungsten.
According to paragraph 1,
A CMP slurry composition for tungsten polishing, wherein the alkyl silane includes a compound of the following formula (2):
<Formula 2>
H ₃ C-(CH ₂ ) _n2 -Si(OR ² ) ₃
In Formula 2, n2 is selected from an integer of 1 to 12, and R ² is selected from hydrogen and a C ₁ -C ₄ alkyl group.
According to paragraph 4,
In Formula 2, n2 is selected from an integer of 5 to 7, and R ² is an ethyl group. A CMP slurry composition for tungsten polishing.
delete According to paragraph 1,
A CMP slurry composition for tungsten polishing, wherein the abrasive particles include silica.
According to paragraph 1,
A CMP slurry composition for tungsten polishing, wherein the abrasive particles have an average particle diameter (D ₅₀ ) of 10 to 200 nm.
According to paragraph 1,
A CMP slurry composition for tungsten polishing, wherein the composition contains 0.001 to 20% by weight of abrasive particles.
According to paragraph 1,
A CMP slurry composition for tungsten polishing, wherein the composition further includes an oxidizing agent, a catalyst, an organic acid, or a combination thereof.
According to clause 10,
A CMP slurry composition for tungsten polishing, comprising 0.01 to 20% by weight of an oxidizing agent, 0.001 to 10% by weight of a catalyst, and 0.001 to 20% by weight of an organic acid in the composition.
According to paragraph 1,
The composition is a CMP slurry composition for tungsten polishing having a pH of 1 to 5.
A method of polishing tungsten, comprising the step of polishing tungsten using the CMP slurry composition for polishing tungsten of any one of claims 1 to 5 and 7 to 12.