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

Abstract

To provide a CMP slurry composition for tungsten polishing, which has a high polishing rate and low erosion, thereby improving flatness after polishing.SOLUTION: A CMP slurry composition for tungsten polishing includes one or more of polar and non-polar solvents, an abrasive, and a compound of chemical formula 3 or a complex compound thereof.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 technology]

[0002] Chemical mechanical polishing (CMP) compositions and methods for polishing (or planarizing) the surface of a substrate are widely known in the art.

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

[0004] Polishing compositions for polishing metal layers (e.g., tungsten) on semiconductor substrates include abrasive particles suspended in an aqueous solution and chemical accelerators, such as oxidizers and catalysts. The catalysts serve to increase the removal rate of tungsten, and several types of catalysts are known to be usable in the field of CMP. However, some catalysts may increase the removal rate but may also result in poor polishing flatness. Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a CMP slurry composition for tungsten polishing, which has a high polishing rate and low erosion, thereby improving the flatness after polishing. [Means for solving the problem]

[0006] 1. According to one embodiment, the CMP slurry composition for tungsten polishing includes at least one solvent selected from polar and non-polar solvents; an abrasive; and a compound of Formula 3 below or a complex thereof:

[0007] [ka] (In the above Chemical Formula 3, R 1 , R 2 , R 3 each independently represents a single bond or a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, R 4 , R 5 , R 6 each independently represents a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, M 1 , M 2 , M 3 are each independently OH or O - M + (M + is a monovalent cation).

[0008] In 2.1, the compound of formula 3 may be a compound of formula 3-1 below or a salt thereof with an alkali metal cation:

[0009] [ka] .

[0010] In 3.1-2, the complex compound may be one in which the compound of Chemical Formula 3 is coordinately bonded to a metal ion.

[0011] In 4.1-3, the metal ion is a divalent iron cation (Fe 2+ ) or iron trivalent cation (Fe 3+ ) may also be used.

[0012] In 5.1-4, the complex compound may be a complex compound represented by the following chemical formula 4:

[0013] [ka] .

[0014] In 6.1-5, the compound of Formula 3 or its complex may be included in the CMP slurry composition in an amount of 0.001 wt % to 10 wt %.

[0015] In 7.1-6, the abrasive may include one or more of an unmodified abrasive and a modified abrasive.

[0016] In 8.7, the modified abrasive can include silica modified with an aminosilane having 1 to 5 nitrogen atoms.

[0017] In 9.1-8, the composition may further include one or more of an oxidizing agent, an amino acid, and an organic acid.

[0018] In 10.9, the composition may include 0.001 wt % to 20 wt % of the abrasive, 0.001 wt % to 10 wt % of the compound of Formula 3 or its complex, 0.001 wt % to 10 wt % of the organic acid, 0.001 wt % to 10 wt % of the amino acid, and 30 wt % to 99 wt % of the solvent.

[0019] In 11.1-10, the CMP slurry composition may have a pH of 2 to 7.

[0020] 12. According to one embodiment, the tungsten polishing method includes polishing tungsten using the CMP slurry composition for tungsten polishing. [Effects of the Invention]

[0021] The present invention can provide a CMP slurry composition for tungsten polishing that has a high polishing rate and low erosion, thereby improving the flatness after polishing. DETAILED DESCRIPTION OF THE INVENTION

[0022] The terms used herein are merely used to describe exemplary embodiments and are not intended to limit the present invention. The singular expressions include the plural expressions unless the context clearly indicates otherwise.

[0023] In this specification, the term "substituted" in "substituted or unsubstituted" means that one or more hydrogen atoms of the functional group in question are substituted with any one of a hydroxyl group, an alkyl group or haloalkyl group having 1 to 20 carbon atoms, an alkenyl group or haloalkenyl group having 2 to 20 carbon atoms, an alkynyl group or haloalkynyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, a cycloalkenyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an amino group, a halo group, a cyano group, and a thiol group.

[0024] In this 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, and more preferably an alkyl group having 1 to 5 carbon atoms.

[0025] 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, and more preferably a cycloalkyl group having 3 to 5 carbon atoms.

[0026] 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.

[0027] In this specification, the terms "divalent aliphatic hydrocarbon group," "divalent alicyclic hydrocarbon group," and "divalent aromatic hydrocarbon group" refer to the above-mentioned "monovalent aliphatic hydrocarbon group," "monovalent alicyclic hydrocarbon group," and "monovalent aromatic hydrocarbon group," each of which has been modified into a divalent form.

[0028] 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, and 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 an cycloalkylene group having 3 to 10 carbon atoms, and more preferably an cycloalkylene group having 3 to 5 carbon atoms; and 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.

[0029] In this specification, when describing a range of values, "X to Y" means X or more and Y or less.

[0030] The present invention relates to a CMP slurry composition for tungsten polishing. The composition not only has a high polishing rate but also low erosion, thereby improving the flatness after polishing. In particular, the CMP slurry composition for tungsten polishing of the present invention is used for polishing tungsten pattern wafers, and can provide the effect of improving the flatness after polishing by having a high oxide film removal rate and low erosion.

[0031] The CMP slurry composition for tungsten polishing of the present invention (hereinafter referred to as "CMP slurry composition") comprises one or more solvents selected from polar and non-polar solvents; an abrasive; and a compound of the following Chemical Formula 3 or a complex compound thereof:

[0032] solvent

[0033] The polar solvent and / or nonpolar solvent can reduce friction when tungsten or a tungsten pattern wafer is polished with an abrasive. The polar solvent and / or nonpolar solvent can be water (e.g., ultrapure water or deionized water), organic amine, organic alcohol, organic alcohol amine, organic ether, organic ketone, etc. Preferably, the solvent can include ultrapure water or deionized water. The polar solvent and / or nonpolar solvent can comprise the remaining amount, for example, 30% to 99% by weight, of the CMP slurry composition.

[0034] abrasives

[0035] The abrasive can polish insulating layer films (e.g., silicon dioxide films) and tungsten pattern wafers at high polishing rates.

[0036] The abrasive may comprise one or more of silica, including colloidal silica, fumed silica, etc., ceria, metal oxides such as alumina, etc. Preferably, the abrasive may comprise colloidal silica, fumed silica, more preferably colloidal silica.

[0037] The abrasive may be spherical or non-spherical particles, with an average primary particle size (D50) of 10 to 200 nm, specifically 20 to 180 nm, and more specifically 30 to 150 nm. This range can increase the polishing rate for the insulating layer and tungsten pattern wafer, which are the polishing targets of the present invention. The "average particle size (D50)" refers to a typical particle size known to those skilled in the art, and refers to the particle size of the particles that make up 50% by volume when the abrasive is distributed from smallest to largest by volume.

[0038] The abrasive may comprise one or more of an unmodified abrasive and a modified abrasive. Preferably, the composition contains a modified abrasive, which can improve the removal rate of the insulating layer film and reduce scratches compared to unmodified abrasives, and can achieve a high removal rate of the tungsten pattern wafer even in a weakly acidic pH range, which is higher than conventional strongly acidic abrasives.

[0039] In one embodiment, the modified abrasive is modified solely with silane having one or more nitrogen atoms, providing a positive charge on the surface of the abrasive. Specifically, the modified abrasive may have a surface zeta potential of +10 mV to +100 mV, specifically +20 mV to +60 mV. This range can promote improvement of the polishing rate of the insulating layer film.

[0040] In one embodiment, the modified abrasive can be prepared by adding an aminosilane having one or more nitrogen atoms to an unmodified abrasive in a molar ratio of 0.02 to 1 relative to the unmodified abrasive under acidic conditions, followed by stirring at 50 to 80°C for 10 to 30 hours. The acidic conditions can be achieved by adding an acid such as hydrochloric acid, hydrofluoric acid, acetic acid, nitric acid, or sulfuric acid. The unmodified abrasive can be, but is not limited to, colloidal silica, fumed silica, or more preferably colloidal silica.

[0041] In one embodiment, the abrasive may be modified with an aminosilane having one or more nitrogen atoms, for example, from 1 to 5. Preferably, the abrasive may be modified with one or more of the aminosilanes having two nitrogen atoms and the aminosilanes having three nitrogen atoms, which will be described later.

[0042] Silane with two nitrogen atoms

[0043] The dinitrogen silane can include a compound of Formula 1, a cation derived from a compound of Formula 1, or a salt of a compound of Formula 1:

[0044] [ka] (In the above Chemical Formula 1, X1, X2, and X3 each independently represent 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; 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 and Y2 each independently represent a single bond, a divalent aliphatic hydrocarbon group, a divalent alicyclic hydrocarbon group, or a divalent aromatic hydrocarbon group; R1, R2, and R3 each independently represent a hydrogen atom, 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.

[0045] In one embodiment, the abrasive may include an abrasive modified with the compound of Formula 1 above.

[0046] 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 each a hydroxyl group or a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms. This allows the compound of Chemical Formula 1 to be more stably bound to the abrasive, thereby extending the life of the abrasive.

[0047] Preferably, Y1 and Y2 may each independently be a divalent aliphatic hydrocarbon group, more preferably an alkylene group having 1 to 5 carbon atoms.

[0048] Preferably, in Chemical Formula 1, R1, R2, and R3 are each independently hydrogen, and Chemical Formula 1 may be an amino group (—NH2)-containing silane.

[0049] For example, the compound of Formula 1 may include one or more of aminoethylaminopropyltrimethoxysilane, aminoethylaminopropyltriethoxysilane, aminoethylaminopropylmethyldimethoxysilane, aminoethylaminopropylmethyldiethoxysilane, aminoethylaminomethyltriethoxysilane, and aminoethylaminomethylmethyldiethoxysilane.

[0050] In another embodiment, the abrasive may include a cation-modified abrasive derived from the compound of Formula 1 above.

[0051] The cation derived from the compound of Formula 1 refers to a cation formed by further bonding hydrogen or a substituent to one or more of the two nitrogen atoms in Formula 1. The cation may be a monovalent cation or a divalent cation. For example, the cation may be represented by any one of Formulas 1-1 to 1-3 below:

[0052] [ka]

[0053] [ka]

[0054] [ka] (In the above Chemical Formulas 1-1 to 1-3, X1, X2, X3, Y1, Y2, R1, R2, and R3 are as defined in the above Chemical Formula 1, respectively.) R4 and R5 are each independently a hydrogen atom, 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.

[0055] In yet another embodiment, the abrasive may include an abrasive modified with a salt of the compound of Formula 1. The salt of the compound of Formula 1 refers to a neutral salt of a cation and anion derived from the compound of Formula 1.

[0056] The cation may be represented by any one of the above-mentioned formulas 1-1 to 1-3. The anion may be a halogen anion (e.g., F - , Cl - , Br - , I - ); carbonate anion (e.g., CO3 2- , HCO3 - ), nitrate anion (CH3COO - ), citrate anion (HOC(COO - )(CH2COO - )2) and other organic acid anions; 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 - ) can be mentioned.

[0057] Silane with three nitrogen atoms

[0058] The trinitrogen silane can include a compound of Formula 2, a cation derived from a compound of Formula 2, or a salt of a compound of Formula 2:

[0059] [ka] (In the above Chemical Formula 2, X1, X2, and X3 are as defined in Chemical Formula 1; Y3, Y4, and Y5 each independently represent a single bond, a divalent aliphatic hydrocarbon group, a divalent alicyclic hydrocarbon group, or a divalent aromatic hydrocarbon group; R6, R7, R8, and R9 each independently represent a hydrogen atom, 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.

[0060] In one embodiment, the abrasive may include an abrasive modified with the compound of Formula 2 above.

[0061] Preferably, in Chemical Formula 2, 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 2, X1, X2, and X3 are each a hydroxyl group or a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms. This allows the compound of Chemical Formula 2 to be more stably bonded to silica, thereby extending the life of the abrasive.

[0062] Preferably, in the above Chemical Formula 2, Y3, Y4, and Y5 may each independently be a divalent aliphatic hydrocarbon group, more preferably an alkylene group having 1 to 5 carbon atoms.

[0063] Preferably, in Chemical Formula 2, R6, R7, R8, and R9 are each independently hydrogen, and Chemical Formula 2 may be an amino group (—NH2)-containing silane.

[0064] For example, the compound of Formula 2 may include one or more of diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropyltriethoxysilane, diethylenetriaminopropylmethyldimethoxysilane, diethylenetriaminopropylmethyldiethoxysilane, and diethylenetriaminomethylmethyldiethoxysilane.

[0065] In another embodiment, the abrasive may include a cation-modified abrasive derived from the compound of Formula 2 above.

[0066] The cation derived from the compound of Formula 2 refers to a cation formed by bonding hydrogen or a substituent to nitrogen in Formula 2. The cation may be a monovalent to trivalent cation. For example, the cation may be represented by any one of Formulas 2-1 to 2-7 below:

[0067] [ka]

[0068] [ka]

[0069] [ka]

[0070] [ka]

[0071] [ka]

[0072] [ka]

[0073] [ka] (In the Chemical Formulas 2-1 to 2-7, X1, X2, X3, Y3, Y4, Y5, R6, R7, R8, and R9 are each as defined in the Chemical Formula 2, R 10 , R 11 , R 12 are each independently a hydrogen atom, 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).

[0074] In yet another embodiment, the abrasive may include an abrasive modified with a salt of the compound of Formula 2. The salt of the compound of Formula 2 refers to a neutral salt of a cation and anion derived from the compound of Formula 2.

[0075] The cation may be represented by any one of Formulas 2-1 to 2-7 above, and the anion may be as described above for the salt portion of Formula 1 above.

[0076] The abrasive may be included in the CMP slurry composition in an amount of 0.001 to 20% by weight, preferably 0.01 to 15% by weight, more preferably 0.05 to 10% by weight, and most preferably 0.1 to 5% by weight, or 0.5 to 3% by weight, within this range, allowing for high polishing rates for insulating films and tungsten pattern wafers.

[0077] Compound of chemical formula 3 or its complex compound

[0078] The compound of Formula 3 can be included in a composition to form a catalyst, which can be a complex compound between the compound of Formula 3 and a metal ion.

[0079] [ka] (In the above Chemical Formula 3, R 1 , R 2 , R 3 each independently represents a single bond or a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, R 4 , R 5 , R 6 each independently represents a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, M 1 , M 2 , M 3 are each independently OH or O - M + (M + is a monovalent cation).

[0080] The compound of Chemical Formula 3 has a closed ring structure with three nitrogen atoms. Also, the compound of Chemical Formula 3 has a —C(═O)M bond at each of the nitrogen atoms. 1 (M 2 or M 3 ) are linked together, resulting in a total of three -C(=O)M 1 (M 2 or M 3 Therefore, when the compound of formula 3 forms a complex compound with a metal ion, the compound of formula 3 has three -C(=O)M 1 (M 2 or M 3 ) are all bound to the metal ion, and the remaining -C(=O)M 1 (M 2 or M 3 ) and the three nitrogen atoms in formula 3 also bond to metal ions, significantly enhancing the stability of the catalyst. As a result, the composition of the present invention can increase the polishing rate of tungsten pattern wafers and improve the flatness after polishing.

[0081] In one embodiment, in Formula 3, R 1 , R 2 , R 3are each independently a substituted or unsubstituted alkylene group having 2 to 3 carbon atoms, R 4 , R 5 , R 6 are each independently a substituted or unsubstituted alkylene group having 1 to 2 carbon atoms, M 1 , M 2 , M 3 may each independently be OH.

[0082] In one embodiment, the monovalent cation in Formula 3 is an alkali metal cation, such as Li + , Na + , K. + It may be something like this.

[0083] For example, the compound of Formula 3 may be a compound of Formula 3-1 below or a salt thereof with an alkali metal cation:

[0084] [ka]

[0085] The complex compound of the compound of Chemical Formula 3 may be a complex compound in which the compound of Chemical Formula 3 is coordinately bonded to a metal ion. The metal ion may be an iron ion, for example, a divalent iron cation (Fe 2+ ) or iron trivalent cation (Fe 3+ When the compound of formula 3 forms a complex compound, the compound of formula 3 may be M 1 , M 2 , and M 3 From H or M + It can also bind to metal ions by detaching.

[0086] In one specific example, the complex compound of the compound of Chemical Formula 3 may be a complex compound represented by the following Chemical Formula 4: As shown in Chemical Formula 4, three nitrogen atoms and three -C(=O)M 1 (M 2 or M 3 ) is bonded to Fe:

[0087] [ka]

[0088] The metal ions may be derived from a compound containing a divalent iron cation, a compound containing a trivalent iron cation, or a hydrate thereof, including, but not limited to, one or more of iron chloride (FeCl), iron nitrate (Fe(NO), iron sulfate (Fe(SO)), or a hydrate thereof.

[0089] The complex compound of the compound of Formula 3 may be formed by a chelate bond forming reaction between the compound of Formula 3 and a compound containing an iron (III) cation or a hydrate thereof.

[0090] The compound of Formula 3 or its complex may be included in the CMP slurry composition in an amount of 0.001 to 10 wt %, preferably 0.001 to 1 wt %, more preferably 0.001 to 0.5 wt %, for example, 0.001 to 0.1 wt %, or 0.001 to 0.01 wt %, which can increase the polishing rate of the tungsten film and improve polishing flatness.

[0091] The CMP slurry composition may further include one or more of an oxidizer, an amino acid, and an organic acid.

[0092] The oxidizing agent can oxidize the tungsten pattern wafer, making it easier to polish the tungsten pattern wafer.

[0093] The oxidizing agent may 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 containing one or more peroxide groups (-OO-) or an element in its highest oxidation state. Preferably, a percompound is used as the oxidizing agent. For example, the percompound may be one or more of hydrogen peroxide, potassium periodate, calcium persulfate, and potassium ferricyanide, preferably hydrogen peroxide.

[0094] The oxidizer may be included in the CMP slurry composition in an amount of 0.01 to 20 wt %, preferably 0.05 to 10 wt %, and more preferably 0.1 to 5 wt %, which can improve the polishing rate of tungsten pattern wafers.

[0095] Amino acids can be included in CMP slurry compositions containing the above-mentioned abrasives to further increase the tungsten removal rate.

[0096] The amino acids may include glycine, lysine, alanine, histidine, serine, glutamine, valine, leucine, phenylalanine, arginine, aspartic acid, glutamic acid, threonine, asparagine, glutamine, cysteine, proline, etc. Preferably, the amino acids may include one or more of glycine, lysine, alanine, and histidine, more preferably glycine.

[0097] The amino acid may be included in the CMP slurry composition in an amount of 0.001 to 10 wt %, preferably 0.005 to 5 wt %, more preferably 0.01 to 1 wt %, and most preferably 0.02 to 0.5 wt %. Within this range, the removal rate of the tungsten film can be increased.

[0098] The organic acid can increase the polishing rate of the tungsten pattern wafer.

[0099] The organic acid may include an organic acid having one or more carboxyl groups, preferably an organic acid having one carboxyl group, for example, one or more of acetic acid, propionic acid, butyric acid, and valeric acid.

[0100] The organic acid may be included in the CMP slurry composition in an amount of 0.001 to 10% by weight, preferably 0.002 to 5% by weight, more preferably 0.005 to 3% by weight, and most preferably 0.01 to 1% by weight. This range enhances the dispersion stability of the abrasive, and can prevent the abrasive from clumping and / or agglomerating even after a long period of time has passed since production.

[0101] The CMP slurry composition may have a pH of 2 to 7. By using the above-described modified silica as an abrasive, the present invention can achieve a high removal rate of tungsten pattern wafers even at a weakly acidic pH compared to conventional strongly acidic pH. In one embodiment, the CMP slurry composition may have a pH of 2 to 6, 3 to 6, 4 to 6, or 5 to 6.

[0102] The CMP slurry composition may further include a compound containing iron trivalent cations or hydrates thereof, specifically, but not limited to, one or more of iron chloride (FeCl), iron nitrate (Fe(NO), iron sulfate (Fe(SO)), or hydrates thereof.

[0103] The iron trivalent cation-containing compound or its hydrate may be included in the CMP slurry composition in an amount of 0.001 to 10 wt %, preferably 0.01 to 1 wt %, and more preferably 0.1 to 0.5 wt %. This range may have the effect of improving catalytic activity stability and maximizing polishing performance.

[0104] The CMP slurry composition may further include a pH adjuster to adjust the pH.

[0105] The pH adjuster may include one or more inorganic acids, such as nitric acid, phosphoric acid, hydrochloric acid, and sulfuric acid, or may include one or more bases, such as aqueous ammonia, sodium hydroxide, potassium hydroxide, ammonium hydroxide, sodium carbonate, and potassium carbonate.

[0106] The CMP slurry composition may further contain conventional additives such as biocides, surfactants, dispersants, and modifiers. The additives may be included in the composition in an amount of 0.001 to 5 wt %, preferably 0.002 to 1 wt %, and more preferably 0.005 to 0.5 wt %. Within this range, the polishing rate is not affected and the additive effects can be realized.

[0107] The method for polishing tungsten of the present invention comprises polishing tungsten using the CMP slurry composition for polishing tungsten of the present invention. In one embodiment, the present invention is a method for polishing a patterned tungsten wafer, comprising polishing the patterned tungsten wafer using the CMP slurry composition for polishing tungsten wafers of the present invention.

[0108] The structure and operation of the present invention will be described in more detail below through preferred examples of the present invention, which are presented as preferred examples of the present invention and should not be construed as limiting the present invention in any way.

[0109] Manufacturing Example 1

[0110] A compound of Formula 5 (Momentive, EDPS) was added dropwise to colloidal silica (PL3, Fuso) with an average particle size of 70 nm in a ratio of 0.04 mol under acidic conditions, and the mixture was reacted at pH 3.8 and 65°C for 8 hours to produce silica (zeta potential: +25 mV, average particle size: 70 nm) modified with the compound of Formula 5. The zeta potential was measured using a Zetasizer ZS (Malvern).

[0111] [ka]

[0112] Example 1

[0113] 0.5 mmol of the compound of Formula 3-1 and 0.5 mmol of iron chloride (FeCl3) were mixed and refluxed, and the mixture was allowed to react for 24 hours to form the complex compound of Formula 4. A CMP slurry composition was prepared containing 1.2 wt % of the modified silica of Preparation Example 1 as an abrasive, 0.001 wt % of the complex compound of Formula 4, 300 ppm of acetic acid as an organic acid, and 0.16 wt % of glycine, based on the total weight of the composition, with the remainder being deionized water. The pH of the CMP slurry composition was adjusted to 5.6 using nitric acid or aqueous ammonia as a pH adjuster, to prepare the CMP slurry composition.

[0114] Examples 2 and 3

[0115] CMP slurry compositions were prepared in the same manner as in Example 1, except that the content of the compound of Formula 4 in Example 1 was changed as shown in Table 1 below. In Table 1 below, "-" means that the corresponding component is not included.

[0116] Comparative Example 1

[0117] A CMP slurry composition was prepared in the same manner as in Example 1, except that 0.002 wt % of the complex compound Fe-EDTA (ethylenediaminetetraacetic acid) was used instead of the complex compound of Formula 4 in Example 1.

[0118] Comparative Example 2

[0119] A CMP slurry composition was prepared in the same manner as in Example 1, except that 0.006 wt % of the complex compound Fe-EDTA was used instead of the complex compound of Formula 4 in Example 1.

[0120] Comparative Example 3

[0121] A CMP slurry composition was prepared in the same manner as in Example 1, except that 0.002 wt % of a complex compound Fe-DTPA (diethylenetriamine pentaacetic acid) was used instead of the complex compound of Formula 4 in Example 1.

[0122] Comparative Example 4

[0123] A CMP slurry composition was prepared in the same manner as in Example 1, except that 0.006 wt % of the complex compound Fe-DTPA was used instead of the complex compound of Formula 4 in Example 1.

[0124] The CMP slurry compositions prepared in the examples and comparative examples were subjected to polishing evaluation under the following polishing evaluation conditions, and the results are shown in Table 1 below.

[0125] [Polishing evaluation conditions]

[0126] 1. Polishing machine: Reflexion LK 300mm (AMAT)

[0127] 2. Polishing conditions -Polishing pad: VP3100 / Rohm and Haas -Head speed: 35 rpm -Platen speed: 33 rpm - Polishing pressure: 1.5psi -Retainer Ring Pressure: 8psi -Slurry flow rate: 250ml / min -Polishing time: 60 seconds

[0128] 3. Polishing target -Tungsten pattern wafer (MIT854, 300mm) The tungsten pattern wafer was subjected to a primary polishing using a mixture of tungsten polishing CMP slurry STARPLANAR7000 (Samsung SDI) and deionized water in a 1:2 weight ratio, to which 2% hydrogen peroxide was added. The tungsten pattern wafer was polished 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 100 rpm, a polishing pressure of 2.0 psi, a retainer ring pressure of 8 psi, and a mixture flow rate of 240 ml / min. This removed the tungsten metal film layer, revealing the oxide film / metal pattern.

[0129] 4. Polishing rate of oxide film (unit: Å / min): After evaluation under the above polishing conditions, the difference in film thickness before and after polishing was converted using an optical interference type film thickness measuring instrument (Reflectometer) to determine the polishing rate of the oxide film.

[0130] 5. Erosion (unit: Å): After evaluation under the above polishing conditions, the pattern profile was measured using an InSight CAP Compact Atomic Profiler (Bruker). Erosion was calculated based on the height difference between the perioxide 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.

[0131] 6. △Erosion (unit: Å): After evaluation under the above polishing conditions, the line / space area in the 0.18 / 0.18 μm pattern area was scanned once in a contact manner over a total of 2 mm, 1 mm to the left and right of the center, and then calculated based on the height difference between the tungsten and the cellulosic.

[0132] 7. Protrusion (unit: Å): After evaluation under the above polishing conditions, a 2 μm×2 μm pattern area was scanned to create a 3D image, and the protrusion was calculated based on the height difference.

[0133] [Table 1]

[0134] As shown in Table 1, the CMP slurry composition of the present invention contains an iron complex compound containing a closed-ring ligand of Formula 3, and thus exhibits similar polishing rate and protrusion while exhibiting improved erosion resistance compared to the conventional iron complex compound containing an open-ring ligand.

[0135] As shown in Table 1, when compared at the same usage content, iron complex compounds having closed-ring ligands provided an erosion improvement effect, with Δ-erosion being improved by about 20 to 50 nm compared to iron complex compounds having open-ring ligands such as Fe-EDTA or Fe-DTPA. Furthermore, when evaluated by content, it was found that even at low contents, the oxide film removal rate was maintained while an erosion improvement effect was observed.

[0136] Simple variations and modifications of the present invention can be easily implemented by those skilled in the art, and all such variations and modifications can be considered to be included within the scope of the present invention.

Claims

1. The method includes at least one solvent selected from polar and non-polar solvents, an abrasive, and a complex compound of the compound represented by the following Chemical Formula 1: The complex compound is a compound of Chemical Formula 1 coordinately bonded to a metal ion, 【Chemistry 1】 (In the above Chemical Formula 1, R １ , R ２ , R ３ each independently represents a single bond or a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, R ４ , R ５ , R ６ each independently represents a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, M １ , M ２ , M ３ are each independently OH or O － M ＋ (M ＋ is a monovalent cation).

2. 2. The CMP slurry composition for polishing tungsten pattern wafers according to claim 1, wherein the compound of Chemical Formula 1 is a compound of Chemical Formula 2 below or a salt thereof with an alkali metal cation: 【Chemistry 2】 。

3. The metal ions are divalent iron cations (Fe ２＋ ) or iron trivalent cation (Fe ３＋ 2. The CMP slurry composition for tungsten polishing according to claim 1, wherein

4. 2. The CMP slurry composition for tungsten polishing according to claim 1, wherein the complex compound is a complex compound represented by the following chemical formula 3: 【Transformation 3】 。

5. 2. The CMP slurry composition for tungsten polishing according to claim 1, wherein the compound of Formula 1 or its complex is contained in the CMP slurry composition in an amount of 0.001 to 10 wt %.

6. 2. The CMP slurry composition for tungsten polishing according to claim 1, wherein the abrasive comprises at least one of an unmodified abrasive and a modified abrasive.

7. 7. The CMP slurry composition for tungsten polishing according to claim 6, wherein the modified abrasive comprises silica modified with aminosilane having 1 to 5 nitrogen atoms.

8. The CMP slurry composition for tungsten polishing according to claim 1, further comprising at least one of an oxidizing agent, an amino acid, and an organic acid.

9. 9. The CMP slurry composition for tungsten polishing according to claim 8, comprising 0.001 wt % to 20 wt % of the abrasive, 0.001 wt % to 10 wt % of the compound of Formula 1 or its complex, 0.001 wt % to 10 wt % of the organic acid, 0.001 wt % to 10 wt % of the amino acid, and 30 wt % to 99 wt % of the solvent.

10. 2. The CMP slurry composition for polishing tungsten according to claim 1, wherein the pH of the CMP slurry composition is 2 to 7.

11. A method for polishing tungsten, comprising the step of polishing tungsten using the CMP slurry composition for tungsten polishing according to any one of claims 1 to 10.

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