KR101260266B1 - Chemical-mechanical polishing slurry composition and method for manufacturing semiconductor device by using the same - Google Patents

Abstract

The present invention relates to a chemical mechanical polishing slurry composition and a method for manufacturing a semiconductor device, the cerium oxide 0.01 to 5% by weight, amino acid, amino sulfonic acid and any one dipole compound selected from the group consisting of 0.001 to 5 weight % And the rest of the solvent.
The chemical mechanical polishing slurry composition of the present invention is a chemical mechanical polishing slurry composition of the present invention, the polishing rate of the silicon oxide film is significantly high, so that it is possible to finish the removal process of the insulating film in a short time, reduce the damage of the polishing surface, time stability and dispersion Excellent stability, low particle generation and scratches.

Description

TECHNICAL-MECHANICAL POLISHING SLURRY COMPOSITION AND METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE BY USING THE SAME

The present invention relates to a chemical mechanical polishing slurry composition and a method for manufacturing a semiconductor device, and more particularly, the polishing rate of the silicon oxide film is remarkably high, so that the process of removing the insulating film can be completed in a short time, and the damage of the polishing surface can be reduced. The present invention relates to a chemical mechanical polishing slurry composition and a method for manufacturing a semiconductor device having excellent stability over time and dispersion stability and low particle generation and scratches.

As the semiconductor device is miniaturized and densified, a finer pattern forming technique is used, and thus the surface structure of the semiconductor device becomes more complicated and the step difference of the surface film becomes larger. In the manufacture of semiconductor devices, chemical-mechanical polishing (CMP) processes are used as the planarization technique for removing the steps in a particular film formed on a substrate.

In the CMP process, the polishing rate, the degree of flattening of the polishing surface, and the degree of scratching are important, and these are determined by the CMP process conditions, the type of slurry, and the type of polishing pad. As the degree of integration increases and the process specifications become stricter, there is a need to quickly planarize an insulating film having a large step.

It is an object of the present invention that the polishing rate of the silicon oxide film is remarkably high, so that the removal process of the insulating film can be completed in a short time, the damage of the polishing surface can be reduced, and the particle generation and scratches are low due to the excellent stability over time and dispersion stability. To provide a chemical mechanical polishing slurry composition.

Another object of the present invention is to provide a method for manufacturing a semiconductor device using the chemical mechanical polishing slurry composition.

Chemical mechanical polishing slurry composition according to an embodiment of the present invention is 0.01 to 5% by weight of cerium oxide, 0.001 to 5% by weight of any one dipole compound selected from the group consisting of amino acids, amino sulfonic acid and combinations thereof, and the rest Content of the solvent.

The chemical mechanical polishing slurry composition may have a positive value of the zeta potential value of the cerium oxide in the range of pH 1 to 7.

The dipole compound may have a difference of at least 3 between the pKa (-) value of the anionic functional group and the pKa (+) value of the cationic functional group.

The amino acids are alanine, valine, leucine, isoleucine, threonine, serine, cysteine, methionine, aspartic acid, asparagine, glutamic acid, glutamine, glycine, n-acetylglycine, lysine, arginine, histidine, phenylalanine, tyrosine, tryptophan, proline, β -Alanine, aminobutyric acid, ornithine, citrulline, homoserine, triyotyrosine, thyroxine, dioxyphenylalanine, derivatives thereof, salts thereof, and combinations thereof.

The amino sulfonic acid may be represented by the following formula (1).

[Formula 1]

H ₂ NR ₁ -SO ₃ H

(In Formula 1, R ₁ is any one selected from the group consisting of an alkylene group having 1 to 10 carbon atoms and an arylene group having 6 to 30 carbon atoms)

The chemical mechanical polishing slurry composition may further include any one pH adjuster selected from the group consisting of inorganic acids, organic acids, and combinations thereof.

According to another embodiment of the present invention, a method of manufacturing a semiconductor device using the chemical mechanical polishing slurry composition is provided.

Hereinafter, the present invention will be described in more detail.

The chemical mechanical polishing slurry composition comprises 0.01 to 5% by weight of cerium oxide, 0.001 to 5% by weight of any dipole compound selected from the group consisting of amino acids, amino sulfonic acids and combinations thereof, and the remainder of the solvent.

Since the chemical mechanical polishing slurry composition does not include an anionic dispersant, the zeta potential value of the cerium oxide has a positive value in the range of pH 1 to 7. Specifically, the chemical mechanical polishing slurry composition may have a zeta potential value of 10 to 50 mV of the cerium oxide in a range of pH 1 to 7, preferably a zeta potential value of 20 to 40 mV in a range of pH 3 to 5 Can be.

As the chemical mechanical polishing slurry composition does not include an anionic dispersant, in particular anionic polymeric dispersant, the surface of the cerium oxide has a positive polarity, and the zeta potential value in the range of pH 1 to 7 is a positive value. When the silicon oxide film surface has a negative polarity, the polishing efficiency is increased by the attractive force between the cerium oxide and the silicon oxide film surface, so that the initial polishing speed in the step pattern is slow. ) Can be suppressed from occurring.

The cerium oxide, which is the abrasive grain, has a lower hardness than silica particles or aluminum oxide particles, but polishes a surface containing silicon such as glass or a semiconductor substrate by a chemical polishing mechanism in which a Si—O—Ce bond is formed between Si and Ce atoms. It is very fast and is advantageous for polishing semiconductor substrates. The cerium oxide may be prepared by calcining cerium carbonate hydrate at 600 ° C. to 900 ° C. in air or wetted from a cerium salt solution.

The cerium oxide may have an average particle diameter of 10 to 500 nm, preferably 10 to 120 nm. If the average particle diameter of the cerium oxide is less than 10nm may be less efficient polishing, if it exceeds 500nm may cause scratches. In addition, the cerium oxide may be included in 0.01 to 5% by weight, preferably 0.1 to 1% by weight based on the entire chemical mechanical polishing slurry composition.

The dipole compound is any one selected from the group consisting of amino acids, amino sulfonic acids and combinations thereof.

The amino acid is a compound containing an amine group at one end and a carboxyl group at the other end, and one end having an amino group has a positive polarity, and the other end having a carboxyl group has a negative polarity. In addition, the amino sulfonic acid is a compound having an amino group at one end and a sulfonic acid group at the other end, and similarly to the amino acid, one end having an amino group has a positive polarity, and the other end having a sulfonic acid group has a negative polarity.

On the other hand, the surface of the cerium oxide in the state containing no anionic dispersant has a positive polarity, the other end having a negative polarity of the dipole is oriented toward the cerium oxide so that the dipole compound is on the surface of the cerium oxide A protective film is formed. For this reason, the dipole compound serves to stabilize the dispersed state of the cerium oxide particles.

Accordingly, the adhesion of the cerium oxide to the surface of the silicon oxide film having a negative polarity can be improved to increase the polishing rate of the silicon oxide film, and the amino sulfonic acid group has a defect on the surface of the silicon oxide film polished by the cerium oxide. defects can be prevented.

The amino acids are alanine, valine, leucine, isoleucine, threonine, serine, cysteine, methionine, aspartic acid, asparagine, glutamic acid, glutamine, glycine, n-acetylglycine, lysine, arginine, histidine, phenylalanine, tyrosine, tryptophan, proline, β -Alanine, aminobutyric acid, ornithine, citrulline, homoserine, triyotyrosine, thyroxine, dioxyphenylalanine and derivatives thereof and mixtures thereof, and alanine or glycine can be preferably used.

The amino sulfonic acid may preferably be represented by the following formula (1).

[Formula 1]

H ₂ NR ₁ -SO ₃ H

In Formula 1, R ₁ may be any one selected from the group consisting of an alkylene group having 1 to 10 carbon atoms and an arylene group having 6 to 30 carbon atoms, and preferably may be an alkylene group having 1 to 5 carbon atoms.

The alkylene group is a divalent atomic group obtained by subtracting two hydrogen atoms from an alkane, and may be represented by the general formula -C _n H _2n- . The arylene group is a divalent atomic group containing one or more benzene rings, for example, benzene ring, biphenyl such as toluene or xylene having an alkyl side chain attached to the benzene ring, such as biphenyl bonded by a single bond, The benzene ring may be a divalent atom group obtained by subtracting two hydrogen atoms from naphthalene or anthracene, such as fluorene, xanthene or anthraquinone, condensed with a cycloalkyl group or a heterocycloalkyl group, or two or more benzene rings.

The alkylene group or the arylene group may be substituted or unsubstituted. Herein, the substituted Iran hydrogen is a halogen atom, a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an amino group, a thio group, a methylthio group, an alkoxy group, a nitrile group, an aldehyde group, an epoxy group, an ether group, an ester group, a carbonyl group, Substituted with any one selected from the group consisting of acetal groups, ketone groups, alkyl groups, perfluoroalkyl groups, cycloalkyl groups, heterocycloalkyl groups, allyl groups, benzyl groups, aryl groups, heteroaryl groups, derivatives thereof, and combinations thereof Means that.

The dipole compound is easy to form a dipole is advantageous in improving polishing properties and dispersion stability. That is, a large difference between the pKa (-) value of the anionic functional group (-COOH, -SO ₃ H) and the pKa (+) value of the cationic functional group (-NH ₂ ) can stably form a dipole in a wide pH range. Can be. For example, for glycine, the pKa (-) value is 2.34 and the pKa (+) value is 9.6. Therefore, it is preferable that the difference between the pKa (-) value and the pKa (+) value of the dipole compound is 3 or more, more preferably 5 or more in pH units. In addition, the more the range between the pKa (−) and pKa (+) values is included in the acidic region, the more suitable the use of the present invention.

Since the dipole compound may have poor dispersion stability when the number of carbons connecting the anionic functional group and the cationic functional group is too large, the carbon number is preferably 1 to 5, more preferably 1 to 2 carbon atoms.

When the silicon oxide film is polished with a cerium oxide slurry not containing the dipole compound, a very large particle defect is generated, which is not suitable as a semiconductor polishing compound, and when the dipole compound is included, the defect is considerably reduced to provide excellent polishing characteristics. Indicates.

The dipole compound may be included in an amount of 0.001 to 5% by weight, preferably 0.01 to 1% by weight, based on the entire chemical mechanical polishing slurry composition. When the content of the dipole compound is less than 0.001% by weight, the effect of increasing the polishing efficiency may be insignificant, may cause damage to the wafer, and when the content of the bipolar compound exceeds 10% by weight, economic efficiency may be reduced.

The chemical mechanical polishing slurry composition may have a pH of 1 to 7, preferably 3 to 5. The pH adjusting agent for adjusting the pH is an acid or inorganic or organic base selected from inorganic acids or organic acids such as nitric acid, hydrochloric acid, sulfuric acid, perchloric acid which can adjust the pH without affecting the properties of the chemical mechanical polishing slurry composition All can be used.

The chemical mechanical polishing slurry composition may further include a quaternary ammonium compound, a lubricant, and the like as necessary.

The quaternary ammonium compound may additionally impart a preservative function and a pH adjusting function, the amount used may be 0.01 to 10% by weight, preferably 0.1 to 5% by weight based on the entire chemical mechanical polishing slurry composition.

Examples of the quaternary ammonium compound include ammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide or tetrabutylammonium hydroxide.

The lubricant is to assist the lubrication function of the chemical mechanical polishing slurry composition, glycerin and ethylene glycol may be used. The lubricant may use 0.01 to 10% by weight, preferably 0.1 to 5% by weight based on the entire chemical mechanical polishing slurry composition.

The solvent included in the chemical mechanical polishing slurry composition may be used as long as it is used in the chemical mechanical polishing slurry composition. For example, deionized water may be used, but the present invention is not limited thereto. In addition, the content of the solvent is the remaining content except the content of the cerium oxide, amino sulfonic acid, dipole compound and additional additives with respect to the entire chemical mechanical polishing slurry composition.

Method of manufacturing a semiconductor device according to another embodiment of the present invention includes the step of polishing the silicon oxide film using the chemical mechanical polishing slurry composition. The method for polishing a silicon oxide film using the chemical mechanical polishing slurry composition can be used as long as it is a polishing method and conditions generally used in the prior art, and is not particularly limited in the present invention. Therefore, in this specification, the detailed description is abbreviate | omitted.

The chemical mechanical polishing slurry composition of the present invention has a significantly high polishing rate of the silicon oxide film, so that the removal process of the insulating film can be completed in a short time, the damage of the polishing surface can be reduced, and the particle generation is excellent due to excellent stability over time and dispersion stability. And scratches are low.

1 is a cross-sectional view showing a substrate used for measuring the polishing properties of the chemical mechanical polishing slurry composition prepared in Experimental Example 1 of the present invention.
2 and 3 are photographs showing the polished wafer surfaces prepared in Comparative Examples 1 and 6 of the present invention.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[Experimental Example 1]

Cerium carbonate hydrate was calcined with a rotary kiln at 860 ° C. to produce cerium oxide particles, and then 3 g of nitric acid was added for deionized water and pH control, followed by pulverization / dispersion with a medium stirred powder grinder. The chemical mechanical polishing slurry composition was prepared by mixing with a dipole compound and deionized water in the same content.

The prepared chemical mechanical polishing slurry composition did not include an anionic dispersant, the cerium oxide had an average particle diameter of 120 nm, and the dispersion had a pH of 4.6. Zeta potential values of the cerium oxide particles were + 33mV at pH 4, + 30mV at pH 5, + 12mV at pH 7 and -19mV at pH 9.

Polishing properties were measured using the chemical mechanical polishing slurry composition prepared above. 1 is a cross-sectional view showing a substrate used for measuring the polishing properties of the prepared chemical mechanical polishing slurry composition. Referring to FIG. 1, the substrate 100 forms a first silicon oxide film 120, a silicon nitride film 130, and the like on a silicon wafer substrate 110, and then forms patterns with various line widths and densities. The second silicon oxide film 140 is formed by plasma CVD using tetraethoxy silane (TEOS). The height of the second silicon oxide layer 140 to be removed from the substrate 100 is about 7000 kPa.

Each of the chemical mechanical polishing slurry compositions prepared above was evaluated for polishing characteristics using a CMP device (G & P Tech Co., Ltd.) at a rotational speed of 150 rpm and a pressure of 300 g / cm ² , respectively. The feed rate of the chemical mechanical polishing slurry composition was 200 ml / min.

Cerium oxide
(weight%) Amino acid ¹⁾
(weight%) Amino sulfonic acid ²⁾
(weight%) Amino acid ³⁾
(weight%) Silicon oxide
Polishing amount (Å / min) pH Wafer surface
condition Comparative Example 1 0.25 0 0 0 13668 4.6 X Example 1 0.25 0.05 0 0 16014 4.6 O Example 2 0.25 0.1 0 0 16284 4.6 O Example 3 0.25 0.5 0 0 16182 4.6 O Example 4 0.25 0 0.05 0 15972 4.6 O Example 5 0.25 0 0.1 0 15822 4.6 O Example 6 0.25 0 0.5 0 16189 4.6 O Example 7 0.25 0 0 0.05 16242 4.6 O Example 8 0.25 0 0 0.1 16164 4.6 O Example 9 0.25 0 0 0.5 16122 4.6 O

1) amino acid: glycine

2) Amino sulfonic acid: Amino sulfonic acid wherein R ₁ in Formula 1 is an alkylene group having 2 carbon atoms

3) Amino Acid: Alanine

Referring to Table 1, it can be seen that Examples 1 to 9 including the dipole compound increased all the removal ability of the silicon oxide film compared to Comparative Example 1.

2 and 3 are photographs showing the polished wafer surfaces prepared in Comparative Examples 1 and 6, respectively. Referring to FIGS. 2 and 3, it can be seen that the wafer surface prepared in Comparative Example 1 has been observed with an optical microscope that large particle defects are formed, thereby damaging the wafer. On the other hand, the wafer surface prepared in Example 6 can be seen that the wafer surface is clean, there is no damage to the wafer.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

100: substrate 110: silicon wafer
120: first silicon oxide film 130: silicon nitride film
140: second silicon oxide film 141: step difference

Claims (7)

0.01 to 5 wt% cerium oxide,
Alanine 0.001-5% by weight, and
The remaining amount of solvent
Chemical mechanical polishing slurry composition comprising a. The method of claim 1,
The chemical mechanical polishing slurry composition is a chemical mechanical polishing slurry composition having a positive value of the zeta potential value of the cerium oxide in the range of pH 1 to 7. The method of claim 1,
Wherein said alanine has a difference of at least 3 between a pKa (-) value of an anionic functional group and a pKa (+) value of a cationic functional group. delete The method of claim 1,
The chemical mechanical polishing slurry composition further comprises amino sulfonic acid,
The amino sulfonic acid is represented by the formula (1) chemical mechanical polishing slurry composition.
[Formula 1]
H ₂ NR ₁ -SO ₃ H
(In Formula 1, R ₁ is any one selected from the group consisting of an alkylene group having 1 to 10 carbon atoms and an arylene group having 6 to 30 carbon atoms) The method of claim 1,
The chemical mechanical polishing slurry composition further comprises any one pH adjuster selected from the group consisting of inorganic acids, organic acids and combinations thereof. A method for manufacturing a semiconductor device comprising polishing using the chemical mechanical polishing slurry composition according to any one of claims 1 to 3, 5 and 6.

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