CMP slurry composition for polishing tungsten pattern wafers and method for polishing tungsten pattern wafers using the same

Abstract

To provide a CMP slurry composition for polishing a tungsten pattern wafer, which can improve the polishing rate and flatness and eliminate a defect in a tungsten pattern wafer surface when polishing the tungsten pattern wafer.SOLUTION: A CMP slurry composition for polishing a tungsten pattern wafer comprises: one or more kinds of a polar solvent and a nonpolar solvent; a polishing agent; and an oxidant. The polishing agent contains silica subjected to property modification by amino silane of which the number of nitrogen atoms is three.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a CMP slurry composition for polishing a tungsten pattern wafer and a method for polishing a tungsten pattern wafer using the same. More specifically, the present invention relates to a CMP slurry composition for polishing a tungsten pattern wafer that improves the polishing rate and flatness of the tungsten pattern wafer and eliminates defects on the polished surface of the tungsten pattern wafer, and a method for polishing a tungsten pattern wafer using the same.

Background Art

[0002] Chemical mechanical polishing (CMP) compositions and methods for polishing (or planarizing) the surface of a substrate are widely known in the related art. A polishing composition for polishing a metal layer (e.g., tungsten) on a semiconductor substrate may include abrasive particles suspended in an aqueous solution and chemical accelerators such as an oxidizing agent, a catalyst, and the like.

[0003] In the process of polishing a metal layer with a CMP composition, there are steps of polishing only the initial metal layer, polishing the metal layer and the barrier layer, and polishing the metal, the barrier layer, and the oxide film. Among these, a tungsten pattern wafer polishing composition is used in the step of polishing the metal layer, the barrier layer, and the oxide film, but excellent polishing planarization can be achieved when the metal layer and the oxide film are polished at an appropriate polishing rate.

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a CMP slurry composition for polishing a tungsten pattern wafer that improves the polishing rate and flatness during polishing of the tungsten pattern wafer and eliminates defects on the surface of the tungsten pattern wafer.

Means for Solving the Problems

[0005] The CMP slurry composition for polishing a tungsten pattern wafer of the present invention contains one or more solvents selected from polar solvents and non-polar solvents; an abrasive; and an oxidizing agent, and the abrasive contains silica modified with an aminosilane having three nitrogen atoms.

[0006] The method for polishing a tungsten pattern wafer of the present invention includes a step of polishing a tungsten pattern wafer using the CMP slurry composition for polishing a tungsten pattern wafer of the present invention.

Effects of the Invention

[0007] The present invention can provide a CMP slurry composition for polishing a tungsten pattern wafer, which improves the polishing rate and flatness during polishing of the tungsten pattern wafer and eliminates defects on the surface of the tungsten pattern wafer.

Modes for Carrying Out the Invention

[0008] In the present specification, in “substituted or unsubstituted”, “substituted” means that one or more hydrogen atoms of the corresponding functional group are substituted with any one of a hydroxyl group, an alkyl group having 1 to 10 carbon atoms or a haloalkyl group, an alkenyl group having 2 to 10 carbon atoms or a haloalkenyl group, an alkynyl group having 2 to 10 carbon atoms or a haloalkynyl group, a cycloalkyl group having 3 to 10 carbon atoms, a cycloalkenyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an arylalkyl group having 7 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an amino group, a halo, a cyano group, and a thiol group.

[0009] In the present specification, the “monovalent aliphatic hydrocarbon group” may be a substituted or unsubstituted linear or branched alkyl group having 1 to 20 carbon atoms, preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms.

[0010] In this specification, the "monovalent alicyclic hydrocarbon group" may be a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, preferably a cycloalkyl group having 3 to 10 carbon atoms, more preferably a cycloalkyl group having 3 to 5 carbon atoms.

[0011] In this specification, the "monovalent aromatic hydrocarbon group" may be a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or a substituted or unsubstituted arylalkyl group having 7 to 20 carbon atoms, preferably an aryl group having 6 to 10 carbon atoms, or an arylalkyl group having 7 to 10 carbon atoms.

[0012] In this specification, the "divalent aliphatic hydrocarbon group", "divalent alicyclic hydrocarbon group" or "divalent aromatic hydrocarbon group" means those obtained by transforming the above-mentioned "monovalent aliphatic hydrocarbon group", "monovalent alicyclic hydrocarbon group" and "monovalent aromatic hydrocarbon group" into divalent forms respectively.

[0013] For example, the "divalent aliphatic hydrocarbon group" may be a substituted or unsubstituted linear or branched alkylene group having 1 to 20 carbon atoms, preferably an alkylene group having 1 to 10 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms; the "divalent alicyclic hydrocarbon group" may be a substituted or unsubstituted cycloalkylene group having 3 to 20 carbon atoms, preferably a cycloalkylene group having 3 to 10 carbon atoms, more preferably a cycloalkylene group having 3 to 5 carbon atoms; the "divalent aromatic hydrocarbon group" may be a substituted or unsubstituted arylene group having 6 to 20 carbon atoms or a substituted or unsubstituted arylalkylene group having 7 to 20 carbon atoms, preferably an arylene group having 6 to 10 carbon atoms, or an arylalkylene group having 7 to 10 carbon atoms.

[0014] In this specification, when describing a numerical range, "X to Y" means not less than X and not more than Y.

[0015] The inventor has used silica modified with aminosilane having three nitrogen atoms as an abrasive in a CMP slurry composition for polishing tungsten pattern wafers containing an abrasive and an oxidizing agent, thereby improving the polishing rate of tungsten pattern wafers during polishing of tungsten pattern wafers, and reducing erosion and the like, improving the flatness of the polished surface of tungsten pattern wafers, and improving scratch defects, and thus completing the present invention. Further, the inventor has been able to improve the polishing rate of tungsten pattern wafers and the flatness of the polished surface of tungsten pattern wafers at a weakly acidic pH as compared with the conventional strongly acidic pH of 1 to 3 by using silica modified with aminosilane having three nitrogen atoms as an abrasive.

[0016] The CMP slurry composition for polishing tungsten pattern wafers of the present invention (hereinafter referred to as "CMP slurry composition") contains one or more solvents selected from polar solvents and non-polar solvents; an abrasive; and an oxidizing agent, and the abrasive contains silica modified with aminosilane having three nitrogen atoms.

[0017] Hereinafter, the components of the CMP slurry composition according to the present invention will be described in detail.

[0018] One or more of polar solvents and non-polar solvents can reduce the friction when polishing a tungsten pattern wafer with an abrasive agent. One or more of polar solvents and non-polar solvents may be water (for example, ultrapure water or deionized water), organic amines, organic alcohols, organic alcohol amines, organic ethers, organic ketones, etc., and preferably may be ultrapure water or deionized water. One or more solvents of polar solvents and non-polar solvents may be contained in the balance in the CMP slurry composition.

[0019] The abrasive can polish an insulating layer film (e.g., silicon oxide film) and a tungsten pattern wafer at a high polishing rate.

[0020] As an abrasive, for example, silica modified with an aminosilane having three nitrogen atoms is spherical or non-spherical particles, and the average particle size (D50) of the primary particles is about 10 nm to 200 nm (for example, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, or 200 nm), specifically about 20 nm to 180 nm, and more specifically about 40 nm to 130 nm. Within the above range, the polishing rate for the insulating layer film and the tungsten pattern wafer to be polished in the present invention can be increased, and surface defects (such as scratches) may not occur after polishing.

[0021] The "average particle size (D50)" means the normal particle size known to those skilled in the art, and when the abrasive is distributed in ascending order from the minimum to the maximum on a weight basis, it means the particle size corresponding to about 50% by weight of the particles.

[0022] As an abrasive, for example, silica modified with an aminosilane having three nitrogen atoms may be contained in an amount of about 0.001 wt% to 20 wt% (for example, 0.001 wt%, 0.002 wt%, 0.003 wt%, 0.004 wt%, 0.005 wt%, 0.006 wt%, 0.007 wt%, 0.008 wt%, 0.009 wt%, 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt% and 20 wt%) in the CMP slurry composition, preferably about 0.01 wt% to 10 wt%, more preferably about 0.05 wt% to 5 wt%, and most preferably about 0.5 wt% to 3 wt%. Within the above range, the insulating layer film and the tungsten pattern wafer can be polished at a sufficient polishing rate, the generation of scratches can be prevented, and the dispersion stability of the composition can be improved.

[0023] The abrasive contains silica modified with an aminosilane having three nitrogen atoms.

[0024] In the case of silica not modified with a silane having less than three nitrogen atoms (unmodified silica), the polishing rate of the tungsten pattern wafer was low or the flatness improvement effect was low. On the other hand, in the case of silica modified with an aminosilane having three nitrogen atoms, the polishing rate of the tungsten pattern wafer and the flatness improvement effect were very high. In addition, silica modified with an aminosilane having three nitrogen atoms can exhibit a high polishing rate and flatness improvement effect of the tungsten pattern wafer in a weakly acidic pH range with a higher pH compared to conventional strong acids.

[0025] Silica modified with an aminosilane having three nitrogen atoms has a positive charge on its surface and may have a surface potential of about 10 mV to 60 mV (for example, 10 mV, 20 mV, 30 mV, 40 mV, 50 mV or 60 mV). Within the above range, the effect of improving flatness and the effect of improving defects after polishing can be obtained.

[0026] In one specific example, the silica may be modified with an aminosilane having three nitrogen atoms as described below.

[0027] The aminosilane having three nitrogen atoms includes the compound of Chemical Formula 1 below, a cation derived from the compound of Chemical Formula 1 below, or a salt of the compound of Chemical Formula 1 below:

[0028]

Chemical Formula

[0029] Preferably, in Chemical Formula 1, X1, X2, and X3 are each independently a hydroxyl group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and at least one of X1, X2, and X3 is a hydroxyl group or a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms. More preferably, in Chemical Formula 1, X1, X2, and X3 are a hydroxyl group or a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms.

[0030] Preferably, Y1, Y2, and Y3 may each independently be a divalent aliphatic hydrocarbon group, more preferably an alkylene group having 1 to 5 carbon atoms.

[0031] Preferably, in Chemical Formula 1, R1 and R2 may each independently be hydrogen.

[0032] For example, the compound of Chemical Formula 1 may include one or more of diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropyltriethoxysilane, diethylenetriaminopropylmethyldimethoxysilane, diethylenetriaminopropylmethyldiethoxysilane, and diethylenetriaminomethylmethyldiethoxysilane.

[0033] In another specific example, the abrasive includes silica modified with a cation derived from the compound of Chemical Formula 1.

[0034] The cation derived from the compound of Chemical Formula 1 means a cation formed by further bonding of hydrogen or a substituent to one or more of the three nitrogens in Chemical Formula 1. The cation may be a monovalent cation to a trivalent cation. For example, the cation may be represented by any one of the following Chemical Formula 1-1 to the following Chemical Formula 1-7:

[0035]

Chemical Formula

[0036]

Chem.

[0037]

Chem.

[0038]

Chem.

[0039]

Chem.

[0040]

Chem.

[0041]

Chem.

[0042] In still another specific example, the abrasive contains silica modified with a salt of the compound of the above chemical formula 1.

[0043] The cation can be represented by any one of the above chemical formulas 1-1 to 1-7. As the anion, a halogen anion (e.g., F - , Cl - , Br - , I -); carbonate anions (e.g., CO3 2- , HCO3 - ), acetate anions (CH3COO - ), citrate anions (HOC(COO - )(CH2COO - )(CH2COO - ), nitrogen-containing anions (e.g., NO3 - ), NO2 3- ); phosphorus-containing anions (e.g., PO4 2- ), HPO4 - ), H2PO4 2- ); sulfur-containing anions (e.g., SO4 - ), HSO4 - ); and inorganic acid anions such as cyanide anions (CN

[0044] Silica modified with the compound of Formula 1, the cation derived from the compound of Formula 1, or the salt of the compound of Formula 1 can be obtained by adding the compound, cation, or salt to be modified to unmodified silica and then reacting for a predetermined period. The unmodified silica may contain one or more of colloidal silica and fumed silica, and preferably may contain colloidal silica.

[0045] The oxidizing agent can oxidize the tungsten patterned wafer and facilitate the polishing of the tungsten patterned wafer.

[0046] The oxidizing agent may contain one or more of inorganic peroxide compounds, organic peroxide compounds, 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, rare earth metal oxides, transition metal oxides, and potassium dichromate. The "peroxide compound" is a compound containing one or more peroxide groups (-O-O-) or a compound containing an element in the highest oxidation state. Preferably, a peroxide compound may be used as the oxidizing agent. For example, the peroxide compound may be one or more of hydrogen peroxide, potassium periodide, calcium persulfate, and potassium ferricyanide, and preferably, hydrogen peroxide.

[0047] The oxidizing agent may be contained in an amount of about 0.01% to 20% by weight (e.g., 0.01% by weight, 0.02% by weight, 0.03% by weight, 0.04% by weight, 0.05% by weight, 0.06% by weight, 0.07% by weight, 0.08% by weight, 0.09% by weight, 0.1% by weight, 0.2% by weight, 0.3% by weight, 0.4% by weight, 0.5% by weight, 0.6% by weight, 0.7% by weight, 0.8% by weight, 0.9% by weight, 1% by weight, 2% by weight, 3% by weight, 4% by weight, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, 10% by weight, 11% by weight, 12% by weight, 13% by weight, 14% by weight, 15% by weight, 16% by weight, 17% by weight, 18% by weight, 19% by weight, or 20% by weight), preferably about 0.05% to 10% by weight, more preferably about 0.1% to 5% by weight. Within this range, the polishing rate of the tungsten pattern wafer can be improved.

[0048] The CMP slurry composition may further contain one or more of a catalyst and an organic acid.

[0049] The CMP slurry composition may further contain one or more of an iron ion compound, a complex compound of an iron ion, and a hydrate thereof as a catalyst.

[0050] The iron ion compound, the iron ion complex compound, or the hydrate thereof can improve the polishing rate of the tungsten metal film.

[0051] The iron ion compound may include a trivalent iron cation-containing compound. The trivalent iron cation-containing compound is not particularly limited as long as the trivalent iron cation exists as a free cation in an aqueous solution state. For example, the trivalent iron cation-containing compound may include one or more of iron chloride (FeCl3), iron nitrate (Fe(NO3)3), and iron sulfate (Fe2(SO4)3), but is not limited thereto.

[0052] The iron ion complex compound may include an iron(III) cation-containing complex compound. The iron(III) cation-containing complex compound may include a compound formed by reacting an iron(III) cation with an organic compound or an inorganic compound having one or more functional groups among carboxylic acids, phosphoric acids, sulfuric acids, amino acids, and amines in an aqueous solution state. The organic compound or the inorganic compound may be, but is not limited to, citric acid, ammonium citrate, p-toluenesulfonic acid (pTSA), PDTA (1,3-propylenediaminetetraacetic acid), EDTA (ethylenediaminetetraacetic acid), DTPA (diethylenetriaminepentaacetic acid), NTA (nitrilotriacetic acid), EDDS (ethylenediamine-N,N'-disuccinic acid), etc. Specific examples of the iron(III) cation-containing complex compound may be, but are not limited to, ferric citrate, ferric ammonium citrate, Fe(III)-pTSA, Fe(III)-PDTA, Fe(III)-EDTA, etc.

[0053] As a catalyst, for example, one or more of an iron ion compound, a complex compound of an iron ion, and a hydrate thereof may be contained in an amount of about 0.001 wt% to 10 wt% (e.g., 0.001 wt%, 0.002 wt%, 0.003 wt%, 0.004 wt%, 0.005 wt%, 0.006 wt%, 0.007 wt%, 0.008 wt%, 0.009 wt%, 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt%) of the composition, preferably about 0.001 wt% to 5 wt%, more preferably about 0.001 wt% to 1 wt%, and most preferably about 0.001 wt% to 0.5 wt%. Within the above range, the polishing rate of the tungsten metal film can be increased.

[0054] The organic acid may be a carboxylic acid such as malonic acid, maleic acid, or malic acid, or an amino acid such as glycine, isoleucine, leucine, phenylalanine, methionine, threonine, tryptophan, valine, alanine, arginine, cysteine, glutamine, histidine, proline, serine, tyrosine, or lysine.

[0055] The organic acid is contained in an amount of about 0.001 wt% to 20 wt% (e.g., 0.001 wt%, 0.002 wt%, 0.003 wt%, 0.004 wt%, 0.005 wt%, 0.006 wt%, 0.007 wt%, 0.008 wt%, 0.009 wt%, 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, and 20 wt%) of the CMP slurry composition, preferably about 0.01 wt% to 10 wt%, more preferably about 0.01 wt% to 5 wt%, and most preferably about 0.01 wt% to 1 wt%. Within the above range, erosion and protrusion can be simultaneously improved during the polishing of the tungsten pattern wafer.

[0056] The CMP slurry composition may have a pH of about 3 to 6 (e.g., 3, 4, 5, or 6), preferably about 4 to 6, and more preferably about 5 to 6. By using the modified silica described above as an abrasive, the present invention can achieve a high polishing rate of the tungsten pattern wafer even at a weakly acidic pH compared to the conventional strong acidity.

[0057] The CMP slurry composition may further contain a pH adjuster to adjust the pH.

[0058] The pH adjuster may contain one or more of inorganic acids such as nitric acid, phosphoric acid, hydrochloric acid, and sulfuric acid, and may contain one or more of organic acids such as organic acids having a pKa value of about 6 or less, such as acetic acid and phthalic acid. The pH adjuster may contain one or more of bases such as aqueous ammonia, sodium hydroxide, potassium hydroxide, ammonium hydroxide, sodium carbonate, and potassium carbonate.

[0059] The CMP slurry composition may further contain ordinary additives such as biocides, surfactants, dispersants, modifiers, and surface active agents. The additives may be contained in the composition in an amount of about 0.001% to 5% by weight, preferably about 0.001% to 1% by weight, and more preferably about 0.001% to 0.5% by weight. Within this range, the polishing rate is not affected, and the effect as an additive can be realized. <0,

[0060] The method for polishing a tungsten-patterned wafer of the present invention includes a step of polishing a tungsten-patterned wafer using the CMP slurry composition for polishing a tungsten-patterned wafer of the present invention.

[0061] Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, this is presented as a preferred exemplification of the present invention, and in no way should it be construed that the present invention is limited thereby.

Example

[0062] The specific specifications of the components used in the following examples and comparative examples are as follows.

[0063] (1) Abrasive before modification: Colloidal silica (Fuso, PL-7) with an average particle size (D50) of 120 nm

[0064] (2) pH adjuster: Nitric acid or aqueous ammonia

[0065] Example 1

[0066] The following compound of Chemical Formula 2 corresponding to 0.04 mmol per gram of the solid content of the abrasive before modification was mixed with the abrasive before modification, and reacted at 25 ° C for 72 hours under the condition of pH 2.5 to produce silica modified with the following compound of Chemical Formula 2 (average particle size (D50): 125 nm).

[0067]

Chemical formula

[0068] Based on the total weight of the CMP slurry composition, 1.5 wt% of the modified silica produced as described above was used as an abrasive, 0.3 wt% of hydrogen peroxide as an oxidizing agent, 0.001 wt% of diammonium ethylenediaminetetraacetate, 0.001 wt% of ferric nitrate nonahydrate which is an iron ion-containing compound, 0.03 wt% of malonic acid as an organic acid, and 0.15 wt% of glycine were contained, and the remaining was deionized water as a solvent, and thus a CMP slurry composition was produced. The pH of the CMP slurry composition was adjusted to pH 5.5 using a pH adjuster.

[0069] Example 2

[0070] A CMP slurry composition was produced in the same manner as in Example 1, except that the hydrogen peroxide content in Example 1 was changed to 0.15 wt%.

[0071] Example 3

[0072] A CMP slurry composition was produced in the same manner as in Example 1, except that the pH of the CMP slurry composition was adjusted to 5.0 using a pH adjuster in Example 1.

[0073] Comparative Example 1

[0074] A CMP slurry composition was produced in the same manner as in Example 1, except that the abrasive before modification was used as the abrasive in Example 1.

[0075] Comparative Example 2

[0076] 3-aminopropyltriethoxysilane corresponding to 0.04 mmol per 1 g of the solid content of the abrasive before modification and the abrasive before modification were mixed and reacted at 25 °C for 72 hours under the condition of pH 2.5 to produce silica modified with 3-aminopropyltriethoxysilane (average particle size (D50): 125 nm). A CMP slurry composition was produced by carrying out the same method as in Example 1 using the produced modified silica.

[0077] Comparative Example 3

[0078] The following compound of Chemical Formula 3 corresponding to 0.04 mmol per 1 g of the solid content of the abrasive before modification and the abrasive before modification were mixed and reacted at 25 °C for 72 hours under the condition of pH 2.5 to produce silica modified with the following compound of Chemical Formula 3 (average particle size (D50): 125 nm). A CMP slurry composition was produced by carrying out the same method as in Example 1 using the produced modified silica.

[0079] [Chemical Formula]

[0080] Comparative Example 4

[0081] A CMP slurry composition was produced by carrying out the same method as in Example 1 except that no oxidizing agent was used in Example 1.

[0082] The CMP slurry composition for tungsten polishing produced in the examples was subjected to polishing evaluation under the following polishing evaluation conditions. The results are shown in Table 1 below.

[0083] [Polishing Evaluation Conditions] 1. Polishing machine: Reflexion LK 300 mm (AMAT) 2. Polishing conditions - Polishing pad: VP3100 / Rohm and Haas - Head speed: 35 rpm - Platen speed: 33 rpm - Polishing pressure: 1.5 psi - Retainer Ring Pressure: 8 psi - Slurry flow rate: 250 ml / min - Polishing time: 60 seconds

[0084] 3. Objects to be polished - Use commercially available tungsten patterned wafers (MIT 854, 300 mm) - A mixed solution was made by mixing CMP slurry STARPLANAR7000 for tungsten polishing (Samsung SDI) and deionized water at a weight ratio of 1:2, and then hydrogen peroxide corresponding to 2% of the weight of the mixed solution was added to the mixed solution. The tungsten patterned wafer was polished on a Reflexion LK 300 mm polishing machine using an IC1010 / SubaIV Stacked (Rodel) polishing pad at a head speed of 101 rpm, a platen speed of 33 rpm, a polishing pressure of 2 psi, a retainer ring pressure of 8 psi, and a flow rate of the mixed solution of 250 ml / min for 60 seconds for the first polishing. Through this, the tungsten metal film layer was removed so that an oxide / metal pattern appeared.

[0085] 4. Analysis methods - Polishing rate (unit: Å / min): The polishing rate of the tungsten metal film was obtained by converting the film thickness difference before and after polishing from the electrical resistance value in the evaluation under the above polishing conditions. The polishing rate of the insulating layer film was obtained by converting the film thickness difference before and after polishing with an optical interference thickness measuring machine (Reflectomer) in the evaluation under the above polishing conditions.

[0086] - Flatness (erosion, unit: Å): After polishing with the CMP slurry composition produced in the examples using the polishing conditions described above, the pattern profile was measured using an InSight CAP Compact Atomic Profiler (Bruker). Erosion was calculated as the height difference between the peroxide and cell-oxide in the 0.18 / 0.18 μm pattern area of the polished wafer. The scan speed was 100 μm / second and the scan length was 2 mm.

[0087]

Table 1

[0088] As shown in Table 1 above, in the composition containing silica modified with an aminosilane having 3 nitrogen atoms and an oxidizing agent like the composition of the present invention, the polishing rate and flatness of the tungsten pattern wafer were all improved.

[0089] On the other hand, in the case of Comparative Example 1 using unmodified silica and Comparative Example 2 using silica modified with an aminosilane having 1 nitrogen atom, there was a problem that the polishing rate of the insulating film was low and the flatness deteriorated. In the case of Comparative Example 3 using silica modified with an aminosilane having 2 nitrogen atoms, there was a problem that the flatness deteriorated. Even when containing silica modified with an aminosilane having 3 nitrogen atoms, in the case of Comparative Example 4 lacking an oxidizing agent, there were problems that the polishing rates of tungsten and the insulating film were low and the flatness deteriorated.

[0090] Simple modifications and changes of the present invention can be easily implemented by those having ordinary knowledge in this field, and all such modifications and changes can be regarded as being included in the scope of the present invention.

Claims

1. One or more solvents selected from polar solvents and non-polar solvents; A polishing agent; An oxidizing agent; A catalyst; and An organic acid comprising, wherein the polishing agent comprises silica modified with an aminosilane having three nitrogen atoms, and is a CMP slurry composition for polishing tungsten patterned wafers, the polishing agent being 0.001% to 20% by weight, the oxidizing agent being 0.01% to 20% by weight, the catalyst being 0.001% to 10% by weight, the organic acid being 0.001% to 20% by weight, and the balance being the solvent comprising a CMP slurry composition for polishing tungsten patterned wafers.

2. The aminosilane having three nitrogen atoms comprises a compound of Chemical Formula 1 below, a cation derived from the compound of Chemical Formula 1 below, or a salt of the compound of Chemical Formula 1 below, the CMP slurry composition for polishing tungsten patterned wafers according to Claim 1: 【Chemical 1】 (In Chemical Formula 1 above, X １ , X ２ and X ３ are each independently hydrogen, a hydroxyl group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylalkyl group having 7 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, X １ , X ２ and X ３ At least one of them is a hydroxyl group, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, Y １ , Y ２ and Y ３ are each independently a divalent aliphatic hydrocarbon group, a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group, R １ and R ２ are each independently hydrogen, a hydroxyl group, a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, a substituted or unsubstituted monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms.).

3. In Chemical Formula 1 above, Said Y １ , Y ２ and Y ３ are each independently an alkylene group having 1 to 5 carbon atoms, Said R １ and R ２ are each independently hydrogen, the CMP slurry composition for polishing a tungsten pattern wafer according to claim 2.

4. The compound of Chemical Formula 1 comprises one or more selected from diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropyltriethoxysilane, diethylenetriaminopropylmethyldimethoxysilane, diethylenetriaminopropylmethyldiethoxysilane, and diethylenetriaminomethylmethyldiethoxysilane, the CMP slurry composition for polishing tungsten patterned wafers according to Claim 2 or 3.

5. The silica modified with an aminosilane having three nitrogen atoms has a positive charge on its surface and has a surface potential of 10 mV to 60 mV, the CMP slurry composition for polishing tungsten patterned wafers according to any one of Claims 1 to 4.

6. The CMP slurry composition for polishing tungsten patterned wafers according to any one of Claims 1 to 5 has a pH of 3 to 6.

7. The silica modified with an aminosilane having three nitrogen atoms has an average particle size (D50) of 10 nm to 200 nm, the CMP slurry composition for polishing tungsten patterned wafers according to any one of Claims 1 to 6.

8. A method for polishing a tungsten patterned wafer, comprising the step of polishing the tungsten patterned wafer using the CMP slurry composition for polishing a tungsten patterned wafer according to any one of Claims 1 to 7.

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