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

Abstract

To provide a CMP slurry composition for tungsten polishing that does not reduce the polishing rate of tungsten, reduces the etching rate of tungsten wafers, and improves the step coverage characteristics of tungsten wafers.SOLUTION: A CMP slurry composition for tungsten polishing, including one or more solvents selected from polar and non-polar solvents, an abrasive, and a corrosion inhibitor, in which the corrosion inhibitor includes a polyaminosilane or a salt thereof having a weight-average molecular weight of 500 to 5,000 g / mol and a method for polishing tungsten using the same are provided.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a CMP slurry composition for tungsten polishing and a method for polishing tungsten using the same.

Background Art

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

[0003] The step of polishing a metal layer with a CMP slurry composition is performed in a stage of polishing only the initial metal layer, a stage of polishing the metal layer and the barrier layer, and a stage of polishing the metal, the barrier layer and the oxide film.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] One object of the present invention is to provide a CMP slurry composition for tungsten polishing that can maintain the polishing rate of tungsten without decreasing, reduce the etching rate of a tungsten wafer, and improve the step performance of the tungsten wafer.

[0006] Another object of the present invention is to provide a method for polishing tungsten using the CMP slurry composition for tungsten polishing.

[0007] According to one embodiment, a CMP slurry composition for tungsten polishing is provided.

Means for Solving the Problems

[0008] The CMP slurry composition for tungsten polishing includes one or more solvents such as a polar solvent and a non-polar solvent, an abrasive, and a corrosion inhibitor, and the corrosion inhibitor includes a polyaminosilane having a weight average molecular weight of 500 g / mol to 5,000 g / mol or a salt thereof.

[0009] According to one embodiment, a method for polishing tungsten includes polishing tungsten using the CMP slurry composition for tungsten polishing.

[0010] It is possible to provide a CMP slurry composition for tungsten polishing that can improve the step performance of a tungsten wafer by reducing the etching rate of the tungsten wafer without reducing the polishing rate of tungsten.

[0011] It is possible to provide a method for polishing tungsten using the CMP slurry composition for tungsten polishing.

Embodiments for Carrying Out the Invention

[0012] Hereinafter, it will be described in detail so that those having ordinary knowledge in the technical field can easily implement specific embodiments. However, the present invention can be embodied in various different forms and is not limited to the embodiments described herein.

[0013] The terms used herein are for illustrative purposes only in describing exemplary embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0014] In this specification, the "weight average molecular weight" can be obtained by using a polystyrene conversion value using gel permeation chromatography (GPC) or by checking a product catalog. For example, the weight average molecular weight can be measured under the following conditions.

[0015] Analytical device: Product of Tosoh Corporation, HLC-8120GPC Column: Product of Tosoh Corporation, G7000HXL + GMHXL + GMHXL Column size: Each 7.8 mm φ × 30 cm, total 90 cm Column temperature: 40 °C Flow rate: 0.8 ml / min Injection volume: 100 μl Eluent: Tetrahydrofuran Detector: Differential refractometer (RI) Standard sample: Polystyrene

[0016] In this specification, "substituted or unsubstituted" in "substituted" means that one or more hydrogen atoms of the corresponding functional group are substituted by any one of a hydroxyl group, a halogen, an alkyl group or haloalkyl group having 1 to 10 carbon atoms, an alkenyl group or haloalkenyl group having 2 to 10 carbon atoms, an alkynyl group or haloalkynyl group having 2 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a cycloalkenyl group having 3 to 10 carbon atoms, an aryl group having 6 to 30 carbon atoms, an arylalkyl group having 7 to 30 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, an amino group, a cyano group, a nitro group or a thiol group.

[0017] In this specification, "monovalent organic group" may mean a monovalent aliphatic hydrocarbon group, a monovalent alicyclic hydrocarbon group or a monovalent aromatic hydrocarbon group.

[0018] In this specification, "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.

[0019] In this specification, "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.

[0020] In this specification, the "monovalent aromatic hydrocarbon group" can be a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 30 carbon atoms, preferably an aryl group having 6 to 10 carbon atoms or an arylalkyl group having 7 to 10 carbon atoms.

[0021] In this specification, the "divalent organic group" can mean a divalent aliphatic hydrocarbon group, a divalent alicyclic hydrocarbon group, or a divalent aromatic hydrocarbon group.

[0022] In this specification, the "divalent aliphatic hydrocarbon group", "divalent alicyclic hydrocarbon group", or "divalent aromatic hydrocarbon group" means that the above-mentioned "monovalent aliphatic hydrocarbon group", "monovalent alicyclic hydrocarbon group", and "monovalent aromatic hydrocarbon group" are each transformed into a divalent form.

[0023] For example, the "divalent aliphatic hydrocarbon group" can 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" can 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" can be a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkylene group having 7 to 30 carbon atoms, preferably an arylene group having 6 to 10 carbon atoms or an arylalkylene group having 7 to 10 carbon atoms.

[0024] When describing the numerical range in this specification, "X to Y" means X or more and Y or less.

[0025] According to one embodiment, it is possible to provide a CMP slurry composition for tungsten polishing, which has the effect of not reducing the polishing rate of tungsten during tungsten polishing, reducing the etching rate of a tungsten pattern wafer, and improving the step performance of the tungsten pattern wafer.

[0026] A CMP slurry composition for tungsten polishing according to an embodiment (hereinafter referred to as "CMP slurry composition") includes one or more solvents of a polar solvent and a non-polar solvent, an abrasive, and a corrosion inhibitor, and the corrosion inhibitor includes a polyaminosilane having a weight average molecular weight of 500 g / mol to 5,000 g / mol or a salt thereof.

[0027] Hereinafter, the components in the CMP slurry composition according to an embodiment will be described in detail.

[0028] Corrosion inhibitor The composition includes a polyaminosilane having a weight average molecular weight of 500 g / mol to 5,000 g / mol or a salt thereof as a corrosion inhibitor. The polyaminosilane may include a polymer of one or more aminosilanes produced by polymerization of aminosilanes.

[0029] The aminosilane can include an aminoalkoxysilane or an aminoaryloxysilane compound having a free amino group together with an alkoxysilane group and / or an aryloxysilane group involved in polymerization.

[0030] The alkoxysilane group or aryloxysilane group can facilitate the production of a polyaminosilane that satisfies the weight average molecular weight by polymerizing aminosilanes. In addition, the alkoxysilane group or aryloxysilane group can facilitate the realization of the above-described effects of the composition of the present application by providing silicon-bonded hydroxyl groups (*-Si-OH) and / or siloxane groups (*-O-Si-O-*) that can be generated during polymerization.

[0031] Here, the "alkoxysilane group" means a functional group in which at least one or more alkoxy groups are bonded to silicon, and does not mean a functional group in which only an alkoxy group is bonded to silicon. The alkoxysilane group may be a functional group in which an alkoxy group is singly bonded to silicon, or a functional group in which an alkoxy group and a functional group other than an alkoxy group are further bonded.

[0032] Here, the "aryloxysilane group" means a functional group in which at least one or more aryloxy groups are bonded to silicon, and does not mean a functional group in which only an aryloxy group is bonded to silicon. The aryloxysilane group may be a functional group in which an aryloxy group is singly bonded to silicon, or may be a functional group in which an aryloxy group and a functional group other than the aryloxy group are further bonded.

[0033] The amino group is not involved in the polymerization, but at least a part thereof may exist in a free state in the polyaminosilane. The free amino group can adsorb to tungsten, thereby acting as a corrosion inhibitor to reduce the etching rate of the tungsten patterned wafer, improve the step performance, and make it easy to prevent the polishing rate of tungsten from decreasing. Further, the amino groups can form hydrogen bonds with each other, or form hydrogen bonds with silicon-bonded hydroxyl groups (*-Si-OH) in the polyaminosilane to stabilize the structure of the polyaminosilane, thereby easily obtaining the effect of the polyaminosilane in the composition.

[0034] Here, the "amino group" means a primary amine group (-NH2), a secondary amine group (-NH-), or a tertiary amine group TIFF2025107165000001.tif25143 may be meant.

[0035] In one embodiment, the polyaminosilane may have silicon-bonded hydroxyl groups (*-Si-OH), siloxane groups (*-O-Si-O-*), and free amino groups.

[0036] In one embodiment, the aminosilane can be an aminosilane having 1 or more nitrogen atoms, for example, 1 to 4, for example, 1 to 3 nitrogen atoms. Specifically, the aminosilane includes a compound of the following formula 1.

[0037]

Chemical formula

[0038] (In the above formula 1, X1, X2, and X3 are each independently hydrogen, a hydroxyl group, a halogen, 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, at least one of X1, X2, and X3 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, Y1 is a divalent aliphatic hydrocarbon group, a divalent alicyclic hydrocarbon group, or a divalent aromatic hydrocarbon group, R1 and R2 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, a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, a functional group of the following formula 2, or a functional group of the following formula 3.)

[0039]

Chemical formula

[0040] (In the above formula 2, * is the bonding site to the nitrogen (N) of formula 1, Y2 is a divalent aliphatic hydrocarbon group, a divalent alicyclic hydrocarbon group, or a divalent aromatic hydrocarbon group, R3 and R4 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 30 carbon atoms.)

[0041]

Chemical formula

[0042] (In the above formula 3, * represents the bonding site to the nitrogen (N) of formula 1, Y3 and Y4 are each independently a divalent aliphatic hydrocarbon group, a divalent alicyclic hydrocarbon group, or a divalent aromatic hydrocarbon group, R5, R6, and R7 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 30 carbon atoms.)

[0043] In one embodiment, 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 the above formula 1, X1, X2, and X3 can be a hydroxyl group or a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms. The hydroxyl group and the substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms can facilitate the polymerization of the aminosilane by an acid or base catalyst.

[0044] In one embodiment, Y1 can be a divalent aliphatic hydrocarbon group, more preferably an alkylene group having 1 to 5 carbon atoms.

[0045] In one embodiment, R1 and R2 can each independently be hydrogen. For example, the above formula 1 can be a silane containing an amino group (-NH2) with one nitrogen atom. For example, the compound of the above formula 1 can be an aminopropyltrialkoxysilane such as 3-aminopropyltriethoxysilane (APTES), 3-aminopropyltrimethoxysilane, etc.

[0046] In one embodiment, R1 is hydrogen and R2 can be the functional group of Formula 2. For example, the compound of Formula 1 can be an aminosilane with two nitrogen atoms. Preferably, Y2 can be a divalent aliphatic hydrocarbon group, more preferably an alkylene group having 1 to 5 carbon atoms. Preferably, R3 and R4 can each independently be hydrogen or an amino group-containing silane with two nitrogen atoms. For example, the compound of Formula 1 can include one or more of aminoethylaminopropyltrimethoxysilane, aminoethylaminopropyltriethoxysilane, aminoethylaminopropylmethyldimethoxysilane, aminoethylaminopropylmethyldiethoxysilane, aminoethylaminomethyltriethoxysilane, and aminoethylaminomethylmethyldiethoxysilane.

[0047] In one embodiment, R1 is hydrogen and R2 can be the functional group of Formula 3. For example, the compound of Formula 1 can be an aminosilane with three nitrogen atoms. Preferably, Y3 and Y4 can each independently be a divalent aliphatic hydrocarbon group, more preferably an alkylene group having 1 to 5 carbon atoms. Preferably, R6 and R7 can each independently be hydrogen or an amino group-containing silane with three nitrogen atoms. For example, the compound of Formula 1 can include one or more of diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropyltriethoxysilane, diethylenetriaminopropylmethyldimethoxysilane, diethylenetriaminopropylmethyldiethoxysilane, and diethylenetriaminomethylmethyldiethoxysilane.

[0048] In one embodiment, the aminosilane can be an aminosilane in salt form, and the aminosilane in salt form can also polymerize to produce a polyaminosilane. The salt of the aminosilane can mean a neutral salt of a cation and an anion derived from the compound of Formula 1 described above.

[0049] The cation can be a quaternary ammonium cation derived from the nitrogen of Formula 1 described above. The anion can be a halogen anion (e.g., F - , Cl - , Br- , I - ); carbonate anions (e.g., CO3 2- , HCO3 - ), acetate anions (CH3COO - ), citrate anions (HOC(COO - )(CH2COO - ), etc.; 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 anions (CN - ), etc. can be mentioned.

[0050] One or more aminosilanes can produce polyaminosilane by polymerization. The polymerization can be carried out in the presence of one or more catalysts in an acid catalyst and / or a base catalyst. As the acid catalyst, strong acids, weak acids, etc., for example, HCl, HNO3, HCOOH, CH3COOH, HOC(=O)-C(=O)OH (oxalic acid), etc. can be used. As the base catalyst, strong bases, weak bases, etc., for example, NaOH, KOH, NH4OH, etc. can be used. The polymerization can be carried out at 25°C to 85°C, for example, 40°C to 70°C. Within the above range, the production of polyaminosilane can be facilitated. The polymerization can be carried out in water or a water-miscible solvent (a mixture of water and an organic solvent). In the above polymerization, the reaction pH can be acidic or basic pH, becoming 2 to 6, 3 to 5, or 9 to 13, for example, 10 to 12. Within the above range, the production of polyaminosilane can be facilitated.

[0051] The composition contains a polyaminosilane having a weight average molecular weight of 500 g / mol to 5,000 g / mol or a salt thereof. By including the polyaminosilane having a weight average molecular weight of 500 g / mol to 5,000 g / mol instead of the aminosilane, the composition can provide the effect of not reducing the polishing rate of tungsten during tungsten polishing, reducing the etching rate of the tungsten wafer, and improving the step performance.

[0052] When the weight average molecular weight of the polyaminosilane is less than 500 g / mol, the effect of adding the polyaminosilane becomes weak, the effect of reducing the etching rate of the tungsten wafer becomes low, and the step performance may not be improved much. When the weight average molecular weight of the polyaminosilane exceeds 5,000 g / mol, the polishing rate during tungsten polishing may be significantly reduced. According to one embodiment, the weight average molecular weight of the polyaminosilane or its salt can be 1,000 g / mol to 3,000 g / mol.

[0053] In one embodiment, the polyaminosilane having a weight average molecular weight of 500 g / mol to 5,000 g / mol or a salt thereof can provide the effect of not reducing the polishing rate of tungsten during tungsten polishing at an acidic to weakly acidic pH, reducing the etching rate of the tungsten wafer, and improving the step performance. For example, the pH can be adjusted by adjusting one or more of the reaction temperature, reaction pH, type and / or concentration of the acid catalyst used, type and / or concentration of the base catalyst used, and / or reaction time when producing the polyaminosilane by polymerization of the aminosilane.

[0054] The composition can be produced by adding a polyaminosilane having a weight average molecular weight of 500 g / mol to 5,000 g / mol or a salt thereof. That is, when producing the composition, it may be difficult to produce a polyaminosilane having a weight average molecular weight of 500 g / mol to 5,000 g / mol by adding an aminosilane.

[0055] The polyaminosilane or its salt having a weight average molecular weight of 500 g / mol to 5,000 g / mol may be contained in the CMP slurry composition in an amount of 0.001 wt% to 10 wt%, for example, 0.001 wt% to 1 wt%. Within the above range, the polishing rate of tungsten does not decrease, the etching rate of the tungsten pattern wafer can be reduced, and the step performance of the tungsten pattern wafer can be easily improved.

[0056] In one embodiment, the composition may contain, as a corrosion inhibitor, a polyaminosilane or its salt having a weight average molecular weight of 500 g / mol to 5,000 g / mol alone. That is, the polyaminosilane or its salt having a weight average molecular weight of 500 g / mol to 5,000 g / mol may be contained at 100 wt% among all the corrosion inhibitors contained in the composition. Here, the "corrosion inhibitor" can include ordinary substances known for reducing the etching rate of tungsten in a polishing composition for tungsten. For example, the corrosion inhibitor can include amino acids, amine compounds, and the like.

[0057] The amino acid may include, but is not limited to, one or more of glycine, lysine, isoleucine, leucine, phenylalanine, methionine, threonine, tryptophan, valine, alanine, arginine, cysteine, glutamine, histidine, proline, serine, tyrosine, lysine.

[0058] The amine compound may be, for example, hexylamine, tetramethyl-p-phenylenediamine, octylamine, diethylenetriamine, dibutylbenzylamine, aminopropylsilanol, aminopropylsiloxane, dodecylamine, a mixture thereof, and the like.

[0059] The amine compound can include a primary amine, a secondary amine, a tertiary amine, or a quaternary amine. The amine compound can further include a monoamine, a diamine, a triamine, a tetraamine, or an amine-based polymer having a large number of repeating amine groups (for example, 4 or more amine groups).

[0060] The amine compound may contain a long-chain alkyl group. The long-chain alkyl group means an alkyl group having 10 or more carbon atoms (for example, 12 or more carbon atoms or 14 or more carbon atoms). The amine compound includes, for example, dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, oleylamine, N-methyldioctylamine, N-methyloctadecylamine, cocoamidopropylamine oxide, benzyldimethylhexadecylammonium chloride, benzalkonium chloride, cocoalkylmethyl[polyoxyethylene(15)]ammonium chloride, octadecylmethyl[polyoxyethylene(15)]ammonium chloride, cetyltrimethylammonium bromide, and the like.

[0061] The amine compound can contain a polyvalent cationic amine. A polyvalent cationic amine (as the term is used in this application) is an amine compound having a number (two or more) of amine groups in which each amine group is cationic (i.e., has a positive charge). Thus, a polyvalent cationic amine can include a polyquaternary amine. A polyquaternary amine means that the amine compound contains two to four quaternary ammonium groups such that the polyquaternary amine becomes a diquaternary amine, a triquaternary amine, or a tetraquaternary amine compound. Diquaternary amine compounds can include, for example, N,N’-methylenebis(dimethyltetradecylammonium bromide), 1,1,4,4-tetrabutylpiperazinediium dibromide, N,N,N’,N’,N’-pentamethyl-N-tallow-1,3-propanediammonium dichloride, N,N’-hexamethylenebis(tributylammonium hydroxide), decamethonium bromide, didodecyl-tetramethyl-1,4-butanediaminium diiodide, 1,5-dimethyl-1,5-diazoniabicyclo(3.2.2)nonane dibromide, and the like. Triquaternary amine compounds can include, for example, N(1),N(6)-didodecyl-N(1),N(1),N(6),N(6)-tetramethyl-1,6-hexanediaminium diiodide. Tetraquaternary amine compounds can include, for example, methanetetrayltetrakis(tetramethylammonium bromide). Polyquaternary amine compounds can further contain a long-chain alkyl group (e.g., having 10 or more carbon atoms). For example, polyquaternary amine compounds having a long-chain alkyl group can include N,N’-methylenebis(dimethyltetradecylammonium bromide), N,N,N’,N’,N’-pentamethyl-N-tallow-1,3-propanediammonium dichloride, didodecyl-tetramethyl-1,4-butanediaminium diiodide, and N(1),N(6)-didodecyl-N(1),N(1),N(6),N(6)-tetramethyl-1,6-hexanediaminium diiodide.

[0062] In another embodiment, the composition may further include a corrosion inhibitor other than a polyaminosilane having a weight average molecular weight of 500 g / mol to 5,000 g / mol or a salt thereof as a corrosion inhibitor. For convenience, a polyaminosilane having a weight average molecular weight of 500 g / mol to 5,000 g / mol or a salt thereof is used as the first corrosion inhibitor, and a corrosion inhibitor other than a polyaminosilane having a weight average molecular weight of 500 g / mol to 5,000 g / mol or a salt thereof is used as the second corrosion inhibitor.

[0063] The second corrosion inhibitor may include one or more of the above-mentioned amino acids and amine compounds. Preferably, the second corrosion inhibitor can be an amino acid, more preferably glycine.

[0064] The second corrosion inhibitor may be contained in the CMP slurry composition at 10 wt% or less, for example, 0.01 wt% to 5 wt%, 0.02 wt% to 2 wt%. Within the above range, the effect of adding a polyaminosilane having a weight average molecular weight of 500 g / mol to 5,000 g / mol or a salt thereof is not affected, and the effect of adding the second corrosion inhibitor can be obtained.

[0065] The corrosion inhibitor may be contained in the CMP slurry composition at 0.001 wt% to 10 wt%, for example, 0.001 wt% to 1 wt%, 0.002 wt% to 0.2 wt%. Within the above range, the polishing rate of tungsten does not decrease, the etching rate of the tungsten wafer is reduced, and the improvement of the step performance can be facilitated.

[0066] Solvent One or more solvents, including polar solvents and non-polar solvents, can reduce the friction when polishing tungsten with an abrasive. One or more of the polar solvents and non-polar solvents can be water (e.g., ultrapure water or deionized water), organic amines, organic alcohols, organic alcohol amines, organic ethers, organic ketones, etc. Preferably, ultrapure water or deionized water can be used. One or more solvents, including polar solvents and non-polar solvents, can be contained in the CMP slurry composition in a residual amount, e.g., 30 wt% to 99 wt%.

[0067] Abrasive The abrasive can polish the insulating layer film (e.g., silicon oxide film) and tungsten at a high polishing rate.

[0068] The abrasive can contain one or more of silica, alumina, ceria, titania, and zirconia as metal or non-metal oxides. In one embodiment, the use of silica as the abrasive can facilitate the realization of the effects of the present application.

[0069] The abrasive can be spherical or non-spherical particles, and the average particle size (D50) of the primary particles can be 10 nm to 200 nm, specifically 20 nm to 180 nm, more specifically 30 nm to 150 nm. Within the above range, the polishing rate for the insulating layer film and tungsten to be polished can be increased, and surface defects (such as scratches) after polishing can be prevented from occurring.

[0070] The "average particle size (D50)" means the normal particle size known to those skilled in the art, and refers to the particle size of the particles corresponding to 50% by volume when the abrasive is distributed in ascending order from the smallest to the largest on a weight basis.

[0071] The abrasive can be contained in the CMP slurry composition in an amount of 0.001 wt% to 20 wt%, preferably 0.01 wt% to 10 wt%, more preferably 0.05 wt% to 5 wt%, and most preferably 0.1 wt% to 3 wt%. Within the above range, the insulating layer film and tungsten can be polished at a sufficient polishing rate, scratches can be prevented from occurring, and the dispersion stability of silica can be improved.

[0072] The abrasive can include one or more of an unmodified abrasive and a modified abrasive.

[0073] In one embodiment, the abrasive can be included in the composition as an unmodified abrasive with the metal or non-metal oxide itself.

[0074] In another embodiment, the abrasive can be included in the composition with the metal or non-metal oxide modified with one or more modifying substances. The modified abrasive can significantly improve the polishing rate and flatness compared to the unmodified abrasive, and can also reduce scratches. In addition, the modified abrasive can achieve a high tungsten polishing rate even in a weakly acidic pH range with a higher pH compared to conventional strong acids.

[0075] Preferably, the modified abrasive can include silica modified with one or more aminosilanes.

[0076] The modified abrasive has a positive charge on its surface and can have a surface potential of 10 mV to 60 mV. Within this range, the flatness improvement effect and the defect improvement effect after polishing can be obtained.

[0077] In one embodiment, the modifying substance can include one or more of the above-mentioned aminosilanes or their salts. The modification can be performed by adding the modifying substance to the unmodified abrasive and then reacting for a predetermined time. In one embodiment, the unmodified abrasive can include one or more of colloidal silica and fumed silica, and preferably can include colloidal silica.

[0078] The CMP slurry composition can further include one or more of an oxidizing agent, a catalyst, and an organic acid.

[0079] The oxidizing agent can oxidize tungsten to make the polishing of tungsten easier.

[0080] The oxidizing agent can include one or more of 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. The "percompound" is a compound that contains one or more peroxide groups (-O-O-) or contains an element in the highest oxidation state. Preferably, a percompound can be used as the oxidizing agent. For example, the percompound can be one or more of hydrogen peroxide, potassium periodide, calcium persulfate, and potassium ferricyanide, preferably hydrogen peroxide. Preferably, the oxidizing agent can be included in the CMP slurry composition immediately before polishing.

[0081] The oxidizing agent can be contained in the CMP slurry composition in an amount of 0.01 wt% to 20 wt%, preferably 0.05 wt% to 10 wt%, more preferably 0.1 wt% to 5 wt%. Within this range, the polishing rate of tungsten can be improved.

[0082] The catalyst can further include one or more of iron ion compounds, iron ion complex compounds, and their hydrates.

[0083] One or more of iron ion compounds, iron ion complex compounds, and their hydrates can improve the polishing rate of tungsten.

[0084] The iron ion compound can 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 can include one or more of iron chloride (FeCl3), iron nitrate (Fe(NO3)3), and iron sulfate (Fe2(SO4)3), but is not limited thereto.

[0085] The iron ion complex compound can include an iron(III) cation-containing complex compound. The iron(III) cation-containing complex compound can include a compound formed by reacting an iron(III) cation with an organic compound or an inorganic compound having one or more functional groups such as carboxylic acids, phosphoric acids, sulfuric acids, amino acids, and amines in an aqueous solution state, or a salt thereof. The organic compound or the inorganic compound can be citrate, 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., but is not limited thereto. Specific examples of the iron(III) cation-containing complex compound can be ferric citrate, ammonium salt of ferric citrate, Fe(III)-pTSA, Fe(III)-PDTA, Fe(III)-EDTA, etc., but is not limited thereto.

[0086] One or more of a catalyst, for example, an iron ion compound, a complex compound of an iron ion, and a hydrate thereof, can be contained in the CMP slurry composition at 0.001 wt% to 10 wt%, preferably 0.001 wt% to 5 wt%, more preferably 0.001 wt% to 1 wt%, and most preferably 0.001 wt% to 0.5 wt%. Within the above range, the polishing rate of the tungsten film can be increased.

[0087] The organic acid can be a carboxylic acid such as malonic acid, maleic acid, and malic acid.

[0088] The organic acid can be contained in the CMP slurry composition at 0.001% to 20% by weight, preferably 0.01% to 10% by weight, more preferably 0.01% to 5% by weight, and most preferably 0.01% to 1% by weight. Within the above range, erosion and protrusion can be simultaneously improved during tungsten polishing.

[0089] The CMP slurry composition can have a pH of 2 to 6. By using the above-mentioned unmodified silica or modified silica as an abrasive in the present invention, a high tungsten polishing rate can be achieved even at a weakly acidic pH compared to the conventional strong acidity.

[0090] The CMP slurry composition may further contain a pH adjuster to adjust the pH.

[0091] The pH adjuster can include one or more of inorganic acids such as nitric acid, phosphoric acid, hydrochloric acid, and sulfuric acid, and can include one or more of organic acids such as organic acids having a pKa value of 6 or less, such as acetic acid and phthalic acid. The pH adjuster can include one or more of bases such as aqueous ammonia, sodium hydroxide, potassium hydroxide, ammonium hydroxide, sodium carbonate, and potassium carbonate.

[0092] The CMP slurry composition can further contain ordinary additives such as biocides, surfactants, dispersants, modifiers, and surface active agents. The additives can be contained in the composition at 0.001% to 5% by weight, preferably 0.001% to 1% by weight, more preferably 0.001% to 0.5% by weight. Within the above range, the polishing rate is not affected, and the effects of the additives can be realized.

[0093] The tungsten polishing method of the present invention includes a step of polishing tungsten using the CMP slurry composition for tungsten polishing of the present invention.

Examples

[0094] Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to preferred embodiments of the present invention. However, this is presented as a preferred exemplification of the present invention and should not be construed as limiting the present invention in any way.

[0095] The specific specifications of the components used in the following examples and comparative examples are as follows. (1) Unmodified abrasive: Colloidal silica (Fuso, PL-7) with an average particle size (D50) of 120 nm (2) pH adjuster: Nitric acid or aqueous ammonia

[0096] Example 1 Having the following amino silane of Formula 4, polymerized at pH 2.5 and 65 °C for 8 hours to produce a polymer of the following amino silane of Formula 4 with a weight average molecular weight of 1,500 g / mol.

[0097]

Chemical formula

[0098] With respect to the total weight of the CMP slurry composition to be produced, it contains 1.5% by weight of unmodified silica as an abrasive, 0.03% by weight of malonic acid as an organic acid, 0.15% by weight of glycine as a corrosion inhibitor, 0.001% by weight of iron(III) nitrate nonahydrate as an iron ion-containing compound, 0.001% by weight of diammonium ethylenediaminetetraacetate, and 0.005% by weight of the polymer of the above-produced amino silane of Formula 4, and deionized water was added to produce the composition. The pH of the composition was adjusted to 2.5 using a pH adjuster. Hydrogen peroxide was mixed immediately before polishing so that it became 0.5% by weight with respect to the total CMP slurry composition, and deionized water was included in the remaining amount to produce a CMP slurry composition for tungsten polishing.

[0099] Example 2 A slurry composition was produced in the same manner as in Example 1, except that 0.01% by weight of the polymer of the amino silane of Formula 4 was contained instead of 0.005% by weight of the polymer of the amino silane of Formula 4 in Example 1.

[0100] Example 3 An aminosilane polymer having a weight-average molecular weight of 1,500 g / mol was produced by polymerizing the following aminosilane of Formula 5 at pH 2.5 and 65°C for 8 hours.

[0101] [Chemical formula] (Me is a methyl group)

[0102] Thereafter, a CMP slurry composition for tungsten polishing was produced in the same manner as in Example 1, except that 0.005% by weight of the polymer of the aminosilane of Formula 5 was used instead of 0.005% by weight of the polymer of the aminosilane of Formula 4.

[0103] Example 4 In Example 3, a slurry composition was produced in the same manner as in Example 3, except that 0.01% by weight of the polymer of the aminosilane of Formula 5 was contained instead of 0.005% by weight of the polymer of the aminosilane of Formula 5.

[0104] Example 5 An aminosilane polymer having a weight-average molecular weight of 1,500 g / mol was produced by polymerizing the following aminosilane of Formula 6 at pH 2.5 and 65°C for 8 hours.

[0105] [Chemical formula] (Me is a methyl group)

[0106] Thereafter, a CMP slurry composition for tungsten polishing was produced in the same manner as in Example 1, except that 0.005% by weight of the polymer of the aminosilane of Formula 6 was used instead of 0.005% by weight of the polymer of the aminosilane of Formula 4.

[0107] Example 6 In Example 5, a slurry composition was produced in the same manner as in Example 5, except that 0.01% by weight of the polymer of the aminosilane of Formula 6 was contained instead of 0.005% by weight of the polymer of the aminosilane of Formula 6.

[0108] Comparative Example 1 In Example 1, a CMP slurry composition was produced in the same manner as in Example 1, except that the polymer of the aminosilane of Formula 4 was not included.

[0109] Comparative Example 2 In Example 1, a CMP slurry composition was produced in the same manner as in Example 1, except that instead of containing the polymer of the aminosilane of Formula 4, 0.01% by weight of the aminosilane of Formula 4 was contained.

[0110] Comparative Example 3 In Example 1, a CMP slurry composition was produced in the same manner as in Example 1, except that when producing the polymer of the aminosilane of Formula 4, the polymerization conditions were changed to contain 0.01% by weight of the polymer of the aminosilane of Formula 4 having a weight average molecular weight of 350 g / mol.

[0111] Comparative Example 4 In Example 1, a CMP slurry composition was produced in the same manner as in Example 1, except that when producing the polymer of the aminosilane of Formula 4, the polymerization conditions were changed to contain 0.01% by weight of the polymer of the compound of Formula 4 having a weight average molecular weight of 5,500 g / mol.

[0112] For the CMP slurry composition for polishing tungsten pattern wafers produced in the examples, polishing evaluation was carried out under the following polishing evaluation conditions. The results are shown in Table 1 below.

[0113] [Polishing Evaluation Conditions] 1. Polisher: Reflexion LK300mm (AMAT) 2. Polishing Conditions - Polishing Pad: IC1010 / Dupont - Head Speed: 101 rpm - Platen Speed: 100 rpm - Polishing Pressure: 2 psi - Retainer Ring Pressure: 9 psi - Slurry Flow Rate: 240 ml / min - Polishing Time: 60 seconds

[0114] 3. Objects to be Polished - Commercially available tungsten patterned wafers (MIT854, 300 mm) were used - CMP slurry STARPLANAR7000 for tungsten polishing (Samsung SDI) and deionized water were mixed at a weight ratio of 1:2, and then hydrogen peroxide corresponding to 2% of the weight of the resulting mixture was added to the resulting mixture. The tungsten patterned wafer was first polished on a Reflexion LK300 mm polisher with an IC1010 / Dupont polishing pad at a Head speed of 101 rpm, a Platen speed of 100 rpm, a polishing pressure of 2 psi, a Retainer Ring Pressure of 9 psi, and a mixture flow rate of 250 ml / min. As a result, the tungsten metal film layer was removed so that an oxide / metal pattern appeared.

[0115] 4. Analysis Methods Abrasion rate (unit: Å / min) : When evaluating under the above polishing conditions, the difference in film thickness before and after polishing was measured. For the oxide film, a reflectometer was used, and for tungsten, the resistance value was measured and then converted to obtain the polishing rates of tungsten and the oxide film respectively. Irosion (unit: nm) : After polishing with the CMP slurry compositions produced in the examples and comparative examples using the above polishing conditions, the pattern profile was measured with an InSight CAP Compact Atomic Profiler (Bruker). The erosion was calculated as the difference in height between peri oxide 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. Etching rate (unit: Å / min): A tungsten non-patterned wafer was cut into a size of 2×2 cm, immersed in a slurry at 60 °C for 5 minutes, and the etching amount before and after immersion was compared and obtained.

[0116]

Table 1

[0117] As shown in Table 1 above, the CMP slurry composition for tungsten polishing in the examples did not reduce the polishing rate of tungsten, reduced the etching rate of the tungsten patterned wafer, and provided the effect of improving the step performance of the tungsten patterned wafer.

[0118] On the contrary, the composition of the comparative example that does not contain polyaminosilane with a weight average molecular weight of 500 g / mol to 5,000 g / mol could not achieve all of the above effects.

[0119] Simple modifications or changes of the present invention can be easily implemented by those with 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. A CMP slurry composition for tungsten polishing, comprising one or more solvents selected from polar solvents and non-polar solvents, an abrasive, and a corrosion inhibitor, wherein the corrosion inhibitor contains a polyaminosilane having a weight average molecular weight of 500 g / mol to 5,000 g / mol or a salt thereof.

2. The CMP slurry composition for tungsten polishing according to claim 1, wherein the polyaminosilane has a silicon-bonded hydroxyl group (*-Si-OH), a siloxane group (*-O-Si-O-*), and a free amino group.

3. The CMP slurry composition for tungsten polishing according to claim 1, wherein the polyaminosilane contains a polymer of aminosilane.

4. The CMP slurry composition for tungsten polishing according to claim 3, wherein the aminosilane contains a compound of the following formula 1. 【Chemical 1】 (In the above formula 1, X １ , X ２ , X ３ is, independently of one another, hydrogen, a hydroxyl group, a halogen, 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 , X ３ At least one of X １ , X ２ , and X ３ 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 is a divalent aliphatic hydrocarbon group, a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group, R １ and R ２ each independently represents 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, a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, a functional group of the following formula 2, or a functional group of the following formula 3.) 【Chemical 2】 (In the above formula 2, * is the bonding site to nitrogen (N) in formula 1, Y ２ is a divalent aliphatic hydrocarbon group, a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group, R ３ and R ４ 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 30 carbon atoms. [Chemical 3] (In the above formula 3, * is the bonding site to nitrogen (N) in formula 1, Y ３ and Y ４ each independently represents a divalent aliphatic hydrocarbon group, a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group, R ５ , R ６ , and R ７ 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 30 carbon atoms. )

5. The CMP slurry composition for tungsten polishing according to claim 3, wherein the aminosilane contains one or more of aminopropyltriethoxysilane, aminopropyltrimethoxysilane, aminoethylaminopropyltrimethoxysilane, aminoethylaminopropyltriethoxysilane, aminoethylaminopropylmethyldimethoxysilane, aminoethylaminopropylmethyldiethoxysilane, aminoethylaminomethyltriethoxysilane, aminoethylaminomethylmethyldiethoxysilane, diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropyltriethoxysilane, diethylenetriaminopropylmethyldimethoxysilane, diethylenetriaminopropylmethyldiethoxysilane, diethylenetriaminomethylmethyldiethoxysilane.

6. The CMP slurry composition for tungsten polishing according to claim 1, wherein the polyaminosilane or its salt having a weight average molecular weight of 500 g / mol to 5,000 g / mol is contained in the CMP slurry composition at 0.001 wt% to 10 wt%.

7. The CMP slurry composition for tungsten polishing according to claim 1, wherein the corrosion inhibitor further contains a corrosion inhibitor other than the polyaminosilane or its salt having a weight average molecular weight of 500 g / mol to 5,000 g / mol.

8. The corrosion inhibitor-containing tungsten CMP slurry composition according to claim 7, wherein the corrosion inhibitor contains one or more of amino acids and amine compounds.

9. The tungsten CMP slurry composition according to claim 1, wherein the abrasive contains one or more of unmodified abrasives and modified abrasives.

10. The tungsten CMP slurry composition according to claim 9, wherein the modified abrasive contains silica modified with one or more aminosilanes or salts thereof.

11. The tungsten CMP slurry composition according to claim 1, wherein the CMP slurry composition further contains one or more of an oxidizing agent, a catalyst, and an organic acid.

12. The composition is 0.001% to 20% by weight of the abrasive, 0.001% to 10% by weight of the corrosion inhibitor, 0.01% to 20% by weight of the oxidizing agent, 0.001% to 10% by weight of the catalyst, 0.001% to 20% by weight of the organic acid, and the balance of the solvent, and is the tungsten CMP slurry composition according to claim 11.

13. A method for polishing tungsten, comprising polishing tungsten using the tungsten CMP slurry composition according to any one of claims 1 to 12.

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