CMP slurry composition for polishing tungsten patterned wafers and method for polishing tungsten patterned 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 of the tungsten pattern wafer while decreasing scratch defects.SOLUTION: A CMP slurry composition for polishing a tungsten pattern wafer includes a solvent and an abrasive agent, where the abrasive agent includes silica modified with a polyethylenimine-derived aminosilane. The CMP slurry composition has a pH of about 4 to 7. Also disclosed is a method of polishing a tungsten pattern wafer employing the composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a CMP slurry composition for polishing tungsten pattern wafers and a method for polishing tungsten pattern wafers using the same, and more particularly to a CMP slurry composition for polishing tungsten pattern wafers that can improve the polishing rate and flatness of tungsten pattern wafers and reduce scratch defects, and a method for polishing tungsten pattern wafers using the same. [Background technology]

[0002] Chemical and mechanical polishing (CMP) compositions and methods for polishing (or planarizing) the surface of a substrate are widely known in the art. A polishing composition for polishing a metal layer (e.g., tungsten) on a semiconductor substrate can include abrasive particles and chemical promoters, such as oxidizers, catalysts, etc., suspended in an aqueous solution.

[0003] The process of polishing a metal layer with a CMP slurry 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 layer. Of these, a tungsten pattern wafer polishing composition is used in the step of polishing the metal layer, barrier layer, and oxide layer, but unless the metal layer and oxide layer are polished at an appropriate polishing rate, excellent polishing planarization cannot be achieved. Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a CMP slurry composition for polishing tungsten patterned wafers, which can improve the polishing rate and flatness of tungsten patterned wafers and reduce scratch defects.

[0005] Another object of the present invention is to provide a method for polishing a tungsten patterned wafer using the CMP slurry composition for polishing a tungsten patterned wafer. [Means for solving the problem]

[0006] 1. In one aspect, a CMP slurry composition for polishing tungsten patterned wafers is provided, the composition comprising a solvent and an abrasive, the abrasive comprising silica modified with a polyethyleneimine-derived aminosilane, and the composition may have a pH of about 4 to 7.

[0007] 2. In the above 1, the polyethyleneimine-derived aminosilane may include a reaction product of polyethyleneimine and a compound of the following Chemical Formula 1, a cation derived from the reaction product, or a salt of the reaction product:

[0008] [ka]

[0009] In the above formula 1, L is a substituted or unsubstituted C1-C 20 Alkylene groups, substituted or unsubstituted C3-C 20 Cycloalkylene groups, substituted or unsubstituted C6-C 20 an arylene group or a combination thereof, X is selected from -F, -Cl, -Br, -I, an epoxy group and a glycidyloxy group, and R1 to R3 are each independently hydrogen, a hydroxyl group, a substituted or unsubstituted C1-C 20 Alkyl groups, substituted or unsubstituted C3-C 20 Cycloalkyl groups, substituted or unsubstituted C6-C 20 Aryl groups, substituted or unsubstituted C1-C 20 Alkoxy groups and substituted or unsubstituted C6-C 20 aryloxy groups, and at least one of R1 to R3 is selected from hydroxyl groups, substituted or unsubstituted C1-C 20 Alkoxy groups and substituted or unsubstituted C6-C 20 It can be selected from aryloxy groups.

[0010] 3. In the above 2, in the above Chemical Formula 1, L is selected from a C1-C5 alkylene group, X is selected from -Cl and a glycidyloxy group, and R1 to R3 are each independently selected from a hydroxyl group, a C1-C5 alkyl group, and a C1-C5 alkoxy group, and at least one of R1 to R3 can be selected from a hydroxyl group and a C1-C5 alkoxy group.

[0011] 4. In the above 2 or 3, the compound of Chemical Formula 1 can be selected from chloropropyltrimethoxysilane, chloropropyltriethoxysilane, glycidyloxypropyltrimethoxysilane, and glycidyloxypropyltriethoxysilane.

[0012] 5. In any one of the above 1 to 4, the polyethyleneimine may have a weight average molecular weight (Mw) of about 500 g / mol to 1,000,000 g / mol as measured by GPC (gel permeation chromatography).

[0013] 6. In any one of 1 to 5 above, the silica modified with the polyethyleneimine-derived aminosilane has a positive charge on the surface, a surface potential of about 10 mV to 60 mV, and an isoelectric point at a pH of about 6 to 10.

[0014] 7. In any one of the above 1 to 6, the silica modified with the polyethyleneimine-derived aminosilane can have an average particle size (D50) of about 10 nm to 200 nm.

[0015] 8. In any one of the above 1 to 7, the composition may further contain one or more of an oxidizing agent, a catalyst, and an organic acid.

[0016] 9. In the above 8, the composition may contain about 0.001% to 20% by weight of the abrasive; about 0.01% to 20% by weight of the oxidizing agent; about 0.001% to 10% by weight of the catalyst; about 0.001% to 20% by weight of the organic acid; and the balance of the solvent.

[0017] 10. According to another aspect, there is provided a method for polishing a tungsten patterned wafer, the method comprising the step of polishing a tungsten patterned wafer using the CMP slurry composition for polishing a tungsten patterned wafer described in any one of 1 to 9 above. [Effects of the Invention]

[0018] The present invention has the effect of providing a CMP slurry composition for polishing tungsten pattern wafers, which can improve the polishing rate and flatness of tungsten pattern wafers and reduce scratch defects, and a method for polishing tungsten pattern wafers using the same. DETAILED DESCRIPTION OF THE INVENTION

[0019] In this specification, the singular expression includes the plural expression unless the context clearly dictates otherwise.

[0020] In this specification, the terms "comprise" or "have" mean that the features or components described in the specification are present, and do not preclude the possibility that one or more other features or components may also be added.

[0021] As used herein, substituted C-C 20 Alkylene groups, substituted C3-C 20 Cycloalkylene groups, substituted C6-C 20 Arylene group, substituted C1-C 20 Alkyl groups, substituted C3-C 20 Cycloalkyl groups, substituted C6-C 20 Aryl groups, substituted C1-C 20 Alkoxy groups and substituted C6-C 20 At least one of the substituents of the aryloxy group is C1-C 20 Alkyl groups, C3-C 20 Cycloalkyl groups and C6-C 20 It can be selected from aryl groups.

[0022] When interpreting elements, they are interpreted as including a margin of error even if there is no other explicit description.

[0023] In this specification, the "to" in "a to b" that represents a numerical range defines ≧a and ≦b.

[0024] The present inventors have confirmed that the use of abrasive particles modified with a polyethyleneimine-derived aminosilane as an abrasive in a CMP slurry composition for polishing tungsten pattern wafers, which contains a solvent and an abrasive, improves the polishing rate of tungsten pattern wafers, reduces erosion, etc., improves the flatness of the polished surface of the tungsten pattern wafer, and reduces scratch defects, thereby completing the present invention. Furthermore, the present inventors have 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 compared to the conventional strongly acidic pH of 1 to 3 by using silica modified with a polyethyleneimine-derived aminosilane as an abrasive.

[0025] A CMP slurry composition for polishing tungsten patterned wafers (hereinafter also referred to as "CMP slurry composition") according to one embodiment of the present invention comprises a solvent and an abrasive, the abrasive comprising silica modified with a polyethyleneimine-derived aminosilane, and the composition may have a pH of about 4 to 7.

[0026] The components of a CMP slurry composition according to one embodiment of the present invention will be described in detail below.

[0027] solvent

[0028] The solvent can reduce friction when polishing a tungsten pattern wafer with an abrasive. The solvent can be a polar solvent, a nonpolar solvent, or a combination thereof, such as water (e.g., ultrapure water, deionized water, etc.), organic amine, organic alcohol, organic alcohol amine, organic ether, organic ketone, etc. According to one specific example, the solvent can be, but is not limited to, ultrapure water or deionized water. The solvent can be included as the balance in the CMP slurry composition.

[0029] abrasives

[0030] The abrasive can polish insulating layer films (eg, silicon oxide films) and tungsten pattern wafers at a high polishing rate.

[0031] The abrasive, for example, silica modified with aminosilane derived from polyethyleneimine, is a spherical or non-spherical particle, and the average particle size (D 50 ) can be, for example, about 10 nm to 200 nm (e.g., 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, or 200 nm), about 20 nm to 180 nm, or about 40 nm to 130 nm. Within the above range, the polishing speed for the insulating layer film and tungsten pattern wafer, which are the polishing targets of the present invention, can be achieved, and surface defects (scratches, etc.) after polishing can be prevented, but the term "average particle size (D 50 )" refers to a typical particle size known to those skilled in the art, and refers to the particle size of particles that account for approximately 50% by volume when the abrasive is distributed from smallest to largest by volume.

[0032] The abrasive, for example, silica modified with polyethyleneimine-derived aminosilane, can be contained in the CMP slurry composition in an amount of, for example, about 0.001 wt % to 20 wt %, for example, about 0.01 wt % to 10 wt %, for example, about 0.05 wt % to 5 wt %, or for example, about 0.5 wt % to 3 wt %, and within these ranges, the insulating layer film and tungsten pattern wafer can be polished at a sufficient polishing rate, scratches can be prevented from occurring, and the dispersion stability of the composition can be excellent, but the amount is not limited to this.

[0033] The abrasive may include silica modified with a polyethyleneimine-derived aminosilane.

[0034] Polyethyleneimine is an amine-based polymer with a repeating unit composed of an amine group and a CH2CH2 spacer, and contains many nitrogen atoms. Silica modified with aminosilane derived from polyethyleneimine, which has many nitrogen atoms, has a significantly higher effect of improving the polishing rate and flatness of tungsten pattern wafers than unmodified silica or silica modified with aminosilanes containing a small number of nitrogen atoms (e.g., one or two nitrogen atoms). In addition, silica modified with aminosilane derived from polyethyleneimine can achieve a high polishing rate and flatness improvement effect for tungsten pattern wafers in a weakly acidic pH range, which is higher than conventional strongly acidic pH ranges.

[0035] The polyethyleneimine may include linear polyethyleneimine, branched polyethyleneimine, or a combination thereof. The linear polyethyleneimine may be represented by the following chemical formula A, and the branched polyethyleneimine may be represented by the following chemical formula B, but is not limited thereto:

[0036] [ka]

[0037] [ka]

[0038] According to one specific example, the weight average molecular weight (Mw) of the polyethyleneimine measured by GPC may be about 500 g / mol to 1,000,000 g / mol, for example, about 1,000 g / mol to 500,000 g / mol, for example, about 2,500 g / mol to 250,000 g / mol, or about 5,000 g / mol to 50,000 g / mol. Within this range, the polishing speed for the insulating layer film and tungsten pattern wafer, which are the polishing targets of the present invention, can be increased and surface defects (scratches, etc.) after polishing can be prevented, but the present invention is not limited to this.

[0039] According to one specific example, silica can be modified with a polyethyleneimine-derived aminosilane, which can include a reaction product of polyethyleneimine and a compound of Formula 1 below, a cation derived from the reaction product, or a salt of the reaction product.

[0040] [ka]

[0041] Here, the term "cation derived from the reaction product of polyethyleneimine and the compound of Formula 1" refers to a compound in which at least one nitrogen atom in the reaction product has a positive charge (i.e., N + ) is carried. Meanwhile, in the "salt of the reaction product of polyethyleneimine and the compound of Chemical Formula 1," the cation is as described above, and the anion is, for example, a halogen anion (e.g., F - ,Cl - ,Br - ,I - ); carbonate anion (e.g., CO3 2- ,HCO3 - ), acetate anion (CH3COO - ), citrate anion (HOC(COO - )(CH2COO - ) 2) and other organic acid anions; and / or nitrogen-containing anions (e.g., NO3- ,NO2 - ); Phosphorus-containing anions (e.g., PO4 3- ,HPO4 2- ,H2PO4 - ); sulfur-containing anions (e.g., SO4 2- ,HSO4 - ); Cyanide anion (CN - ) and other inorganic acid anions.

[0042] In the above formula 1, L is a substituted or unsubstituted C1-C 20 Alkylene groups, substituted or unsubstituted C3-C 20 Cycloalkylene groups, substituted or unsubstituted C6-C 20 For example, L can be selected from substituted or unsubstituted C-C 10 It can be an alkylene group, for example a substituted or unsubstituted C1-C5 alkylene group. According to one embodiment, L can be, but is not limited to, an n-propylene group.

[0043] In Formula 1, X can be selected from -F, -Cl, -Br, -I, an epoxy group, and a glycidyloxy group. In one specific example, X can be selected from -Cl and a glycidyloxy group, but is not limited thereto.

[0044] In the above Chemical Formula 1, R1 to R3 each independently represent a hydrogen atom, a hydroxyl group, a substituted or unsubstituted C1-C 20 Alkyl groups, substituted or unsubstituted C3-C 20 Cycloalkyl groups, substituted or unsubstituted C6-C 20 Aryl groups, substituted or unsubstituted C1-C 20 Alkoxy groups and substituted or unsubstituted C6-C 20 aryloxy groups, and at least one of R1 to R3 is selected from hydroxyl groups, substituted or unsubstituted C1-C 20 Alkoxy groups and substituted or unsubstituted C6-C 20 For example, R1 to R3 can each independently be selected from hydrogen, a hydroxyl group, a substituted or unsubstituted C1-C10 Alkyl groups and substituted or unsubstituted C1-C 10 At least one of R1 to R3 is selected from a hydroxyl group and a substituted or unsubstituted C1-C 10 In another example, R1 to R3 are each independently selected from a hydroxyl group, a C1-C5 alkyl group, and a C1-C5 alkoxy group, with at least one of R1 to R3 being selected from a hydroxyl group and a C1-C5 alkoxy group. In one specific example, R1 to R3 are each independently selected from a methoxy group and an ethoxy group, but are not limited thereto.

[0045] According to one embodiment, the compound of Formula 1 can be selected from chloropropyltrimethoxysilane, chloropropyltriethoxysilane, glycidyloxypropyltrimethoxysilane, and glycidyloxypropyltriethoxysilane.

[0046] Silica modified with a reactant of polyethyleneimine and the compound of Formula 1, a cation derived from the reactant, or a salt of the reactant can be prepared by adding the compound, cation, or salt to be modified to unmodified silica and then allowing the mixture to react for a predetermined period of time. The unmodified silica may include at least one of colloidal silica and fumed silica, and preferably includes colloidal silica.

[0047] According to one specific example, silica modified with polyethyleneimine-derived aminosilanes has a positive charge on the surface, a surface potential of about 10 mV to 60 mV (e.g., 10, 20, 30, 40, 50, or 60 mV), and an isoelectric point of about pH 6 to 10, for example about pH 6 to 8, or in another example, about pH 7 to 8.

[0048] In addition to the solvent and the abrasive, the CMP slurry composition may further include one or more of an oxidizer, a catalyst, and an organic acid.

[0049] oxidizing agent

[0050] The oxidizing agent can oxidize the tungsten pattern wafer, making it easier to polish the tungsten pattern wafer.

[0051] 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, rare earth metal oxides, transition metal oxides, and potassium dichromate, which may be used alone or in combination. Here, the term "percompound" refers to a compound containing one or more peroxide groups (-OO-) or an element in its highest oxidation state. According to one embodiment, the oxidizing agent may include a percompound (e.g., hydrogen peroxide, potassium periodate, calcium persulfate, potassium ferricyanide, etc.). According to another embodiment, the oxidizing agent may be, but is not limited to, hydrogen peroxide.

[0052] The oxidizing agent may be included in the CMP slurry composition in an amount of, for example, about 0.01 wt % to 20 wt %, for example, about 0.05 wt % to 10 wt %, or still another example, about 0.1 wt % to 5 wt %, and within this range, the polishing rate of the tungsten pattern wafer can be improved, but the amount is not limited to this.

[0053] catalyst

[0054] The catalyst can improve the polishing rate of the tungsten pattern wafer, and examples thereof include iron ion compounds, iron ion complex compounds, and hydrates thereof.

[0055] The iron ion compound may include, for example, a compound containing a trivalent iron cation. The trivalent iron cation-containing compound is not particularly limited as long as it is a compound in which the trivalent iron cation exists as a free cation in an aqueous solution, and examples of such compounds include, but are not limited to, iron chloride (FeCl), iron nitrate (Fe(NO)), and iron sulfate (Fe(SO)).

[0056] The iron ion complex compound may include, for example, a complex compound containing a trivalent iron cation. The trivalent iron cation complex compound may include a compound formed by reacting an aqueous solution of a trivalent iron cation with an organic or inorganic compound having one or more functional groups, such as carboxylic acids, phosphates, sulfates, amino acids, and amines. Examples of the organic or inorganic compound include citrate, ammonium citrate, paratoluenesulfonic acid (pTSA), 1,3-propylenediaminetetraacetic acid (PDTA), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), nitrilotriacetic acid (NTA), and ethylenediamine-N,N'-disuccinic acid (EDDS). Specific examples of iron trivalent cation-containing complex compounds include, but are not limited to, ferric citrate, ammonium ferric citrate, Fe(III)-pTSA, Fe(III)-PDTA, and Fe(III)-EDTA.

[0057] The catalyst, for example, one or more of an iron ion compound, an iron ion complex compound, and a hydrate thereof, may be included in the CMP slurry composition in an amount of, for example, about 0.001 wt % to 10 wt %, for example, about 0.001 wt % to 5 wt %, for example, about 0.001 wt % to 1 wt %, and for example, about 0.001 wt % to 0.5 wt %, and within this range, the polishing rate of the tungsten pattern wafer can be improved, but the amount is not limited to this.

[0058] organic acid

[0059] The organic acid can keep the pH of the CMP slurry composition stable. Examples of the organic acid include carboxylic acids such as malonic acid, maleic acid, and malic acid, and amino acids such as glycine, isoleucine, leucine, phenylalanine, methionine, threonine, tryptophan, valine, alanine, arginine, cysteine, glutamine, histidine, proline, serine, tyrosine, and lysine.

[0060] The organic acid may be contained in the CMP slurry composition in an amount of, for example, about 0.001 wt % to 20 wt %, for example, about 0.01 wt % to 10 wt %, for example, about 0.01 wt % to 5 wt %, or for example, about 0.01 wt % to 1 wt %, and the pH of the CMP slurry composition can be kept stable within these ranges, but the amount is not limited to these.

[0061] The CMP slurry composition may have a pH of about 4 to 7, for example, greater than about 4 to 7, for example, about 4 to 6, for example, greater than about 4 to 6, for example, about 4.5 to 6, for example, greater than about 4.5 to 6, or for example, about 5 to 6. By using the above-described modified silica as an abrasive, the present invention can achieve a higher polishing rate for tungsten patterned wafers at a weakly acidic pH compared to conventional strongly acidic pHs.

[0062] The CMP slurry composition may further include a pH adjuster to adjust the pH.

[0063] pH adjuster

[0064] The pH adjuster may include one or more inorganic acids, such as nitric acid, phosphoric acid, hydrochloric acid, and sulfuric acid, and may include one or more organic acids, such as acetic acid and phthalic acid, having a pKa value of about 6 or less. The pH adjuster may include one or more bases, such as ammonia water, sodium hydroxide, potassium hydroxide, ammonium hydroxide, sodium carbonate, and potassium carbonate.

[0065] In addition to the above-mentioned components, the CMP slurry composition may further contain, as necessary, common additives such as biocides, surfactants, dispersants, modifiers, surface active agents, etc. The additives may be contained in the composition in an amount of, for example, about 0.001 wt % to 5 wt %, for example, about 0.001 wt % to 1 wt %, or still another example, about 0.001 wt % to 0.5 wt %, and within these ranges, the polishing rate is not affected while the additive effects can be realized, but the amount is not limited thereto.

[0066] According to another aspect, there is provided a method for polishing a tungsten patterned wafer, the method comprising polishing the tungsten patterned wafer using the CMP slurry composition for polishing a tungsten patterned wafer described above.

[0067] The present invention will be described in more detail below with reference to examples, which are presented as preferred examples of the present invention and should not be construed as limiting the present invention in any way.

[0068] Example

[0069] The specific specifications of the components used in the following examples and comparative examples are as follows:

[0070] (1) Abrasive before modification: Colloidal silica (PL-7, Fuso) with an average particle size (D50) of 120 nm

[0071] (2) pH adjuster: nitric acid or ammonia water

[0072] Example 1

[0073] The unmodified abrasive was mixed with trimethoxysilylpropyl-modified polyethyleneimine (50% in isopropanol, Product Code: SSP-060, Gelest) in an amount of 0.04 mmol per solid content of the unmodified abrasive, and the mixture was reacted at 25°C under pH 2.5 conditions for 72 hours to produce silica (average particle size (D50): 125 nm) modified with aminosilane derived from polyethyleneimine.

[0074] A CMP slurry composition was prepared by adding 1.5 wt% of the modified silica prepared above as an abrasive, 0.01 wt% of Fe(III)-EDTA as a catalyst, 0.15 wt% of acetic acid as an organic acid, and deionized water as a solvent, based on the total weight of the CMP slurry composition. The pH of the CMP slurry composition was adjusted to 5.5 using a pH adjuster. Then, 0.3 wt% of hydrogen peroxide was added as an oxidizer.

[0075] Example 2

[0076] A CMP slurry composition was prepared in the same manner as in Example 1, except that instead of trimethoxysilylpropyl-modified polyethyleneimine, a polyethyleneimine-derived aminosilane was used, which was prepared by dissolving 1.0 mmol of [3-(2,3-epoxypropoxy)propyl]trimethoxysilane (EPO, 98% purity, Sigma-Aldrich) and 3.0 mmol of hyperbranched polyethyleneimine (PEI, Mw = 60,000, Sigma-Aldrich) in 150 mL of toluene, stirring at 80°C for 24 hours, and then drying under reduced pressure.

[0077] Comparative Example 1

[0078] A CMP slurry composition was prepared in the same manner as in Example 1, except that the unmodified abrasive was used as the abrasive.

[0079] Comparative Example 2

[0080] A CMP slurry composition was prepared in the same manner as in Example 1, except that the silica was modified using aminopropyltriethoxysilane ((3-Aminopropyl)triethoxysilane 99%, Sigma-Aldrich) instead of trimethoxysilylpropyl-modified polyethyleneimine.

[0081] Comparative Example 3

[0082] A CMP slurry composition was prepared in the same manner as in Example 1, except that the pH of the CMP slurry composition was changed to 3.9 using a pH adjuster.

[0083] Comparative Example 4

[0084] A CMP slurry composition was prepared in the same manner as in Example 1, except that the pH of the CMP slurry composition was changed to 7.1 using a pH adjuster.

[0085] The CMP slurry compositions for tungsten polishing produced in the examples and comparative examples were subjected to polishing evaluation under the polishing evaluation conditions below, and the results are shown in Table 1 below.

[0086] [Polishing evaluation conditions]

[0087] 1. Polishing machine: Reflexion LK 300mm (AMAT)

[0088] 2. Polishing conditions -Polishing pad: VP3100 / Rohm and Haas -Head speed: 35rpm -Platen speed: 33rpm - Polishing pressure: 1.5psi -Retainer Ring Pressure: 8psi -Slurry flow rate: 250ml / min -Polishing time: 60 seconds

[0089] 3. Polishing target -Commercially available tungsten patterned wafers (MIT 854, 300mm) are used - The tungsten pattern wafer was subjected to primary polishing for 60 seconds using a Reflexion LK300mm polisher with 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 mixture flow rate of 250 ml / min, after mixing tungsten polishing CMP slurry STARPLANAR7000 (Samsung SDI) with deionized water in a 1:2 weight ratio and adding 2% hydrogen peroxide by weight of the mixture. This removed the tungsten metal film layer and revealed the oxide / metal pattern.

[0090] 4.Analysis method Polishing rate (unit: Å / min): The polishing rate of the tungsten metal film was calculated by converting the difference in film thickness before and after polishing under the above-mentioned polishing conditions from the electrical resistance value. The polishing rate of the insulating layer film was calculated by converting the difference in film thickness before and after polishing under the above-mentioned polishing conditions using a reflectometer. Flatness (erosion, unit: Å): After polishing with the CMP slurry compositions prepared in the examples and comparative examples under the above polishing conditions, the pattern profile was measured using an InSight CAP Compact Atomic Profiler (Bruker). Erosion was calculated as the height difference between the peri oxide and cell oxide in the 0.18 / 0.18 μm pattern area of ​​the polished wafer. The scan speed was 100 μm / s, and the scan length was 2 mm.

[0091] [Table 1]

[0092] As can be seen from Table 1, when a tungsten pattern wafer was polished using the CMP slurry compositions of Examples 1 and 2, which contained silica modified with polyethyleneimine-derived aminosilane and had a pH within the range of the present invention, the polishing rate and flatness were superior to those of Comparative Examples 1 to 4, which did not contain silica modified with polyethyleneimine-derived aminosilane.

[0093] The present invention has been described above with reference to the preferred embodiments. Those skilled in the art will understand that the present invention can be embodied in various modified forms 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 defined by the appended claims, not the foregoing description, and all variations within the scope of the claims should be construed as being within the scope of the present invention.

Claims

1. A CMP slurry composition for polishing tungsten pattern wafers, comprising a solvent and an abrasive, The abrasive comprises silica modified with aminosilane derived from polyethyleneimine; The composition has a pH of 4 to 7. The polyethyleneimine-derived aminosilane comprises a reaction product of polyethyleneimine and a compound of the following Chemical Formula 1, a cation derived from the reaction product, or a salt of the reaction product. 【Chemistry 1】 In the above Chemical Formula 1, L is selected from a substituted or unsubstituted C1-C20 alkylene group, a substituted or unsubstituted C3-C20 cycloalkylene group, a substituted or unsubstituted C6-C20 arylene group, or a combination thereof; X is selected from —F, —Cl, —Br, —I, an epoxy group, and a glycidyloxy group; R1 to R3 are each independently selected from hydrogen, a hydroxyl group, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C1-C20 alkoxy group, and a substituted or unsubstituted C6-C20 aryloxy group, provided that at least one of R1 to R3 is selected from a hydroxyl group, a substituted or unsubstituted C1-C20 alkoxy group, and a substituted or unsubstituted C6-C20 aryloxy group.

2. In the formula 1, L is selected from C1-C5 alkylene groups; X is selected from —Cl and a glycidyloxy group; 2. The CMP slurry composition for polishing tungsten pattern wafers according to claim 1, wherein R1 to R3 are each independently selected from a hydroxyl group, a C1-C5 alkyl group, and a C1-C5 alkoxy group, and at least one of R1 to R3 is selected from a hydroxyl group and a C1-C5 alkoxy group.

3. 2. The CMP slurry composition for polishing tungsten patterned wafers according to claim 1, wherein the compound of Chemical Formula 1 is selected from the group consisting of chloropropyltrimethoxysilane, chloropropyltriethoxysilane, glycidyloxypropyltrimethoxysilane, and glycidyloxypropyltriethoxysilane.

4. The polyethyleneimine has a weight average molecular weight (Mw) measured by GPC (gel permeation chromatography) of 500 g / mol to 1,000,000 g / mol. CMP slurry composition for polishing tungsten pattern wafers according to any one of claims 1 to 3.

5. The silica modified with the polyethyleneimine-derived aminosilane has a positive charge on the surface, a surface potential of 10 mV to 60 mV, and an isoelectric point at a pH of 6 to 10. CMP slurry composition for polishing tungsten pattern wafers according to any one of claims 1 to 4.

6. The silica modified with the polyethyleneimine-derived aminosilane has an average particle size (D50) of 10 nm to 200 nm. CMP slurry composition for polishing tungsten pattern wafers according to any one of claims 1 to 5.

7. 7. The CMP slurry composition for polishing tungsten patterned wafers according to claim 1, wherein the composition further comprises one or more of an oxidizing agent, a catalyst, and an organic acid.

8. The composition comprises: 0.001% to 20% by weight of said abrasive; 0.01% to 20% by weight of said oxidizing agent; 0.001% to 10% by weight of said catalyst; 0.001% to 20% by weight of said organic acid; and 8. The CMP slurry composition for polishing tungsten patterned wafers according to claim 7, which contains the remaining amount of the solvent.

9. A method for polishing a tungsten pattern wafer, comprising the step of polishing a tungsten pattern wafer using the CMP slurry composition for polishing a tungsten pattern wafer according to any one of claims 1 to 8.

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