Polishing composition and method of polishing substrate having improved defect reduction

Abstract

To provide a polishing composition and a polishing method that exhibit desirable planarization efficiency, uniformity and dielectric removal rate while minimizing scratches.SOLUTION: The polishing composition is an aqueous alkaline chemical mechanical polishing composition. The aqueous alkaline chemical mechanical polishing composition includes a quaternary ammonium compound having a phenyl group, enabling improved reduction of defects on silicon oxide substrates and enabling good silicon oxide removal rates.SELECTED DRAWING: None

Description

[Technical Field]

[0001] Field of Invention The present invention relates to an alkaline polishing composition and a method for polishing a substrate having improved defect reduction with a good insulator removal rate. More specifically, the present invention relates to an alkaline polishing composition and a method for polishing a substrate having improved defect reduction with a good insulator removal rate, wherein the polishing composition comprises a quaternary ammonium compound having a phenyl group to improve defect reduction on a substrate containing a silicon dioxide insulator, and at least a portion of the silicon dioxide is removed from the substrate. [Background technology]

[0002] Background of the Invention In the manufacture of integrated circuits and other electronic devices, multiple layers of conductive materials, semiconductor materials, and insulating materials are deposited on or removed from the surface of a semiconductor wafer. Thin layers of conductive materials, semiconductor materials, and insulating materials can be deposited by multiple deposition techniques. Common deposition techniques in modern processing include physical vapor deposition (PVD), also known as sputtering, chemical vapor deposition (CVD), plasma-accelerated chemical vapor deposition (PECVD), and electrochemical plating (ECP).

[0003] As layers of material are sequentially deposited and removed, the top surface of the wafer becomes non-planar. Subsequent semiconductor processing (e.g., metallization) requires the wafer to have a flat surface, so planarization is necessary. Planarization is useful for removing undesirable surface topography and surface defects, such as rough surfaces, aggregated material, crystal lattice damage, scratches, and contaminated layers or materials.

[0004] Chemical mechanical planarization or chemical mechanical polishing (CMP) is a common technique used to planarize substrates, such as semiconductor wafers. In conventional CMP, the wafer is mounted on a carrier assembly and positioned in contact with a polishing pad within the CMP apparatus. The carrier assembly applies controllable pressure to the wafer, pressing it against the polishing pad. This pad is moved relative to the wafer by an external driving force (e.g., rotated). Simultaneously, a polishing composition ("slurry") or other polishing solution is provided between the wafer and the polishing pad. In this way, the wafer surface is polished and flattened by the chemical and mechanical action of the pad surface and the slurry.

[0005] Certain advanced device designs require polishing compositions that provide improved silicon dioxide removal efficiency at lower point-of-use (POU) abrasive weight percentages, as well as reduced scratch defects for improved overall polishing processes and product yield percentages. As the size of structures on semiconductor devices continues to shrink, performance standards that were once acceptable for planarization and defect reduction when polishing insulating materials are becoming increasingly unacceptable. Scratches that were once considered acceptable are now limiting yields. [Overview of the project] [Problems that the invention aims to solve]

[0006] Therefore, there is a need for polishing compositions and methods that exhibit desirable planarization efficiency, uniformity, and insulation removal rate while minimizing defects, such as scratches. [Means for solving the problem]

[0007] Summary of the Invention The present invention relates to water, abrasive particles, optionally a pH adjuster, optionally a biocide, a pH greater than 7, and formula (I): [ka] [wherein, R1, R2 and R3 are independently selected from the group consisting of phenyl, benzyl and linear or branched C1-C5 alkyl, and X - is Br - 、Cl - 、I - 、F - and OH - is an anion selected from the group consisting of] Provided is a chemical mechanical polishing composition containing a quaternary ammonium compound having

[0008] Also, the present invention relates to water, 0.1 to 40% by weight of abrasive grains, optionally a pH adjuster, optionally a biocide, a pH of 7 or more, 0.001 to 1% by weight of formula (I):

Chemical formula

[0009] Furthermore, the present invention relates to water, 5 to 25% by weight of colloidal silica abrasive grains, a pH adjuster, optionally a biocide, a pH of 8 to 13, 0.001 to 1% by weight of formula (I):

Chemical formula

[0010] The present invention provides a substrate containing silicon dioxide, water, abrasive particles, optionally a pH adjuster, optionally a biocide, a pH greater than 7, formula (I): [ka] [In the formula, R1, R2 and R3 are independently selected from the group consisting of phenyl, benzyl and linear or branched C1-C5 alkyl groups, X - , Br - Cl - , I - F - and OH - An anion selected from the group consisting of [ The present invention provides a chemical mechanical polishing composition comprising a quaternary ammonium compound having a polishing surface, a chemical mechanical polishing pad having a polishing surface, and a method for chemically polishing a substrate, comprising generating dynamic contact with a downforce of 3 to 35 kPa at the interface between the polishing surface of the chemical mechanical polishing pad and the substrate, and dispersing the chemical mechanical polishing composition on the chemical mechanical polishing pad at or near the interface between the chemical mechanical polishing pad and the substrate, thereby removing a portion of silicon dioxide from the substrate. [Effects of the Invention]

[0011] The chemical-mechanical polishing composition and method of the present invention enable improved defect reduction and a good silicon dioxide removal rate. [Modes for carrying out the invention]

[0012] Detailed description of the invention Throughout this specification, the following abbreviations have the meanings set forth below unless otherwise specified: L = liter, mL = milliliter, kPa = kilopascal, Å = angstrom, nm = nanometer, min = minute, rpm = revolutions per minute, wt% = weight%, RR = removal rate, mmol = millimoles, Br - = Bromide, Cl - = Chloride, I - = Yogid, F - =Fluoride, OH - =Hydroxide, PS =Polishing slurry of the present invention, PC =Comparative polishing slurry.

[0013] The term "chemical-mechanical polishing" or "CMP" refers to a process in which a substrate is polished by chemical and mechanical forces alone, and is distinguished from electrochemical-mechanical polishing (ECMP), in which an electrical bias is applied to the substrate. The terms "quaternary ammonium compound" and "quaternary ammonium salt" are used interchangeably herein, as quaternary ammonium compounds are water-soluble or water-dispersible salts. The term "TEOS" means silicon dioxide formed by the decomposition of tetraethyl orthosilica (Si(OC2H5)4). The terms "composition" and "slurry" are used interchangeably throughout this specification. The term "halide" means chloride, bromide, fluoride, and iodide. The terms "a" and "an" refer to both singular and plural forms. All percentages are by weight unless otherwise specified. All numerical ranges include thresholds and can be combined in any order, unless it is logical to restrict such numerical ranges to sum to 100%.

[0014] The chemical-mechanical polishing composition of the present invention is useful for polishing substrates containing silicon dioxide. The chemical-mechanical polishing composition comprises water, abrasive particles, optionally a pH adjuster, optionally a biocide, a pH greater than 7, and formula (I): [ka] [In the formula, R1, R2 and R3 are independently selected from the group consisting of phenyl, benzyl and linear or branched C1-C5 alkyl groups, X - , Br - Cl - , I - F - and OH - An anion selected from the group consisting of [ The present invention comprises (preferably consisting of) quaternary ammonium compounds for reducing defects and improving the rate of silicon dioxide removal from the substrate. A mixture of the quaternary ammonium compounds of the present invention can also be included in the chemical-mechanical polishing composition of the present invention.

[0015] As used herein, the term "improved silicon dioxide removal rate" refers to the rate of silicon dioxide removal (measured in Å / min) resulting from polishing a substrate with a chemical-mechanical polishing composition containing a quaternary ammonium compound having a phenyl group, and means that at least the following formula is satisfied. A>A0

[0016] In the formula, A is the silicon dioxide removal rate (Å / min) for a chemical-mechanical polishing composition containing the claimed quaternary ammonium compound used in the method of the present invention for polishing a substrate, measured under the polishing conditions described in the example, and A0 is the silicon dioxide removal rate (Å / min) obtained under the same conditions in which only silica abrasive grains are present.

[0017] As used herein, the term "improved polishing defect performance" refers to the defect performance obtained by including a quaternary ammonium compound having formula (I) in the chemical-mechanical polishing composition used in the chemical-mechanical polishing method of the present invention, and means that at least the following formula is satisfied. X <X0

[0018] In the formula, X is the defect (i.e., post-CMP / hydrogen fluoride (HF) scratch or defect) of the chemical-mechanical polishing composition containing the substance used in the method of the present invention, measured under the polishing conditions described in the example, and X0 is the defect (i.e., post-CMP / hydrogen fluoride scratch or defect) obtained under the same conditions in which only silica abrasive grains are present.

[0019] Preferably, the chemical-mechanical polishing composition of the present invention contains a quaternary ammonium compound having formula (I) in an amount of 0.001 to 1% by weight, more preferably 0.1 to 1% by weight, and most preferably 0.1 to 0.5% by weight.

[0020] Preferably, the quaternary ammonium compound of the present invention is of formula (I): [ka] [In the formula, R1, R2 and R3 are independently selected from the group consisting of phenyl and C1-C2 alkyl groups, X - , Br - Cl - and OH - An anion selected from the group consisting of, more preferably R1, R2 and R3 are independently selected from the group consisting of C1-C2 alkyl, X - , Br - and Cl - A halogen is selected from the following, most preferably R1, R2 and R3 are C1 alkyl or methyl (-CH3), X - , Br - and Cl - Selected from halogens consisting of the following: It has the following properties. A mixture of preferred quaternary ammonium compounds can also be included in the chemical-mechanical polishing composition of the present invention.

[0021] Exemplary quaternary ammonium compounds among the preferred quaternary ammonium compounds mentioned above are quaternary ammonium salts selected from the group consisting of phenyltrimethylammonium chloride, phenyltrimethylammonium bromide, and phenyltrimethylammonium hydroxide. The most preferred quaternary ammonium salt is selected from the group consisting of phenyltrimethylammonium chloride and phenyltrimethylammonium bromide. A mixture of such quaternary ammonium salts can be included in the chemical-mechanical polishing composition of the present invention.

[0022] The water contained in the chemical-mechanical polishing composition used in the chemical-mechanical polishing method of the present invention is preferably at least one of deionized water and distilled water in order to limit accidental impurities.

[0023] The chemical-mechanical polishing composition used in the chemical-mechanical polishing method of the present invention contains 0.1 to 40% by weight of abrasive grains, preferably 5 to 30% by weight, and more preferably 10 to 20% by weight. The abrasive grains that are preferably used have an average particle size of <200 nm, more preferably 75 to 150 nm, and most preferably 100 to 150 nm.

[0024] Abrasive particles for use in the chemical-mechanical polishing composition used in the chemical-mechanical polishing method of the present invention include, for example, inorganic oxides, inorganic hydroxide oxides, metal borides, metal carbides, metal nitrides, polymer particles, and mixtures containing at least one of the above. Suitable inorganic oxides include, for example, silica (SiO2), alumina (Al2O3), zirconia (ZrO2), ceria (CeO2), manganese oxide (MnO2), titanium oxide (TiO2), or combinations thereof. Modified forms of these inorganic oxides, such as organic polymer-coated inorganic oxide particles and inorganic coated particles, can also be used as desired. Suitable metal carbides, borides, and nitrides include, for example, silicon carbide, silicon nitride, silicon carbonitride (SiCN), boron carbide, tungsten carbide, zirconium carbide, aluminum boride, tantalum carbide, titanium carbide, or combinations thereof.

[0025] The preferred abrasive grain for use in the chemical-mechanical polishing composition used in the chemical-mechanical polishing method of the present invention is colloidal silica. Preferably, the colloidal silica used contains at least one of precipitated silica and aggregated silica. Preferably, the colloidal silica used has an average particle size of <200 nm, more preferably 75 to 150 nm, most preferably 100 to 150 nm, and accounts for 0.1 to 40% by weight, preferably 5 to 30% by weight, more preferably 10 to 20% by weight of the chemical-mechanical polishing composition. Examples of commercially available colloidal silica include Klebosol® II 1630 colloidal silica with an average particle size of 139 nm, Klebosol® II 1630 colloidal silica with an average particle size of 145 nm, and Klebosol® II 1730 colloidal silica with a particle size of 130 nm. These are all manufactured by Merck KgAA, Darmstadt, Germany, and are all available from DuPont.

[0026] Optionally, the chemical-mechanical polishing composition may contain a biocide, for example, KORDEK™ MLX (9.5-9.9% methyl-4-isothiazolin-3-one, 89.1-89.5% water, and ≤1.0% related reaction product) or KATHON™ ICP III (KATHON and KORDEK are trademarks of International Flavors & Fragrances, Inc.), which contains the active ingredients 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one, respectively, manufactured by International Flavors & Fragrances, Inc.

[0027] When a biocide is included in the chemical-mechanical polishing composition of the present invention, the biocide is included in an amount of 0.0001% to 0.1% by weight, preferably 0.001% to 0.05% by weight, more preferably 0.001% to 0.01% by weight, and even more preferably 0.001% to 0.005% by weight.

[0028] The chemical-mechanical polishing composition used in the chemical-mechanical polishing method of the present invention has a pH of 7, preferably 7 to 12, and more preferably 10 to 11.

[0029] The chemical-mechanical polishing composition used may optionally contain one or more pH adjusters to maintain the pH within a preferred range. Preferably, the pH adjuster is selected from one or more of sodium hydroxide, potassium hydroxide, and ammonium salts, such as ammonium halides or nitrates.

[0030] The substrate polished in the chemical-mechanical polishing method of the present invention contains silicon dioxide. The silicon dioxide in the substrate includes, but is not limited to, boric acid silicate glass (BPSG), plasma-reinforced tetraethyl orthosilica (PETEOS), thermal oxides, undoped silicate glass, and high-density plasma (HDP) oxides.

[0031] The chemical-mechanical polishing pad used in the chemical-mechanical polishing method of the present invention can be any suitable polishing pad known in the art. The chemical-mechanical polishing pad can be optionally selected from woven and non-woven polishing pads. The chemical-mechanical polishing pad can be made of any suitable polymer with various densities, hardnesses, thicknesses, compressibility, and moduli. The chemical-mechanical polishing pad can be grooved and perforated as desired.

[0032] The quaternary ammonium compound having formula (I) contained in the chemical-mechanical polishing composition used in the chemical-mechanical polishing method of the present invention provides improved polishing defect resistance. Preferably, the inclusion of the quaternary ammonium compound having formula (I) in the chemical-mechanical polishing composition results in a >50% reduction in polishing defect resistance (i.e., post-CMP / hydrogen fluoride scratch) when measured under the polishing conditions described in the example. That is, preferably, the following formula is satisfied. (X0-X) / X0 * 100>50

[0033] In the formula, X is the polishing defect (i.e., post-CMP / hydrofluoride scratch or defect) of a chemical-mechanical polishing composition containing the asymmetric quaternary ammonium compound represented by formula (I) used in the method of the present invention, measured under the polishing conditions described in the example, and X0 is the polishing defect (i.e., post-CMP / hydrofluoride scratch or defect) obtained under the same conditions in which only silica abrasive grains are present.

[0034] The chemical-mechanical polishing composition used in the chemical-mechanical polishing method of the present invention enables operation at low nominal polishing pad pressures, for example, 3 to 35 kPa. Low nominal polishing pad pressure improves polishing performance by reducing scratches and other undesirable polishing defects, and minimizes damage to fragile materials. [Examples]

[0035] The following examples are intended to illustrate the present invention and not to limit its scope.

[0036] In the examples below, unless otherwise specified, the temperature and pressure conditions are ambient temperature and standard pressure.

[0037] In the example below, the following materials were used.

[0038] Polishing removal rate experiments were conducted on 8-inch blanket wafers. An Applied Materials Mirra® polisher was used in Example 1, and an Applied Materials Reflexion® polisher was used in Example 2. Polishing Example 1 used a VisionPad 5000 / K7® polyurethane polishing pad, and polishing Example 2 used an IC1010 polyurethane polishing pad (both commercially available from Rohm and Haas Electronic Materials CMP Inc.). Polishing was performed with a downforce of 20.7 kPa (3 psi), a chemical-mechanical polishing slurry composition flow rate of 150 mL / min in Example 1 and 250 mL / min in Example 2, a table rotation speed of 93 rpm, and a carrier rotation speed of 87 rpm. Removal rate was determined by measuring the film thickness before and after polishing using a KLA-Tencor FX200 measuring tool. The defect performance reported in the examples was determined using a scanning electron microscope after hydrofluoric acid polishing and subsequent cleaning ("Pst HF"). All TEOS wafers after Pst-HF cleaning were inspected using the Surfscan® SP2 defect inspection system available from KLA-Tencor. Defect information, including their coordinates on the wafer, was recorded in KLARF (KLA results file), and then transferred to the eDR-5200 defect review system available from KLA-Tencor. A random sample of 100 defect images was selected and examined by the eDR-5200 system. These 100 images were classified into various defect types, such as chatter marks (scratches), particles, and pad polishing debris. Based on the classification results from these 100 images, the total number of scratches on the wafer was determined.

[0039] Example 1 Chemical mechanical polishing composition, TEOS RR and defect reduction Aqueous chemical-mechanical polishing slurries were prepared as shown in Table 1 below. A 2% by weight aqueous KOH solution was added to each slurry to maintain the desired pH.

[0040] [Table 1]

[0041] [Table 2]

[0042] In the present invention, slurry PS-1 demonstrated improved TEOS RR, reduced defect count, and reduced scratches compared to two comparative slurries, PC-1 and PC-2.

[0043] Example 2 Chemical mechanical polishing composition, TEOS RR and defect reduction Aqueous chemical-mechanical polishing slurries were prepared as shown in Table 3 below. A 2% by weight aqueous KOH solution was added to each slurry to maintain the desired pH.

[0044] [Table 3]

[0045] [Table 4]

[0046] In the slurries PS-2, PS-3, and PS-4 of the present invention, which contain phenyltrimethylammonium chloride, an improvement in TEOS RR and a reduction in scratches were demonstrated compared to comparative example PC-3, which contains only abrasive particles and water.

Claims

1. Water, an abrasive, optionally a pH adjuster, optionally a biocide, a pH greater than 7 and a composition of formula (I): 【Chemistry 7】 [In the formula, R １ , R ２ and R ３ is phenyl, benzyl and straight or branched chain C １ ~C ５ alkyl; － Br － , Cl － , I － , F － and OH － is an anion selected from the group consisting of and a quaternary ammonium compound having the formula: Chemical mechanical polishing compositions.

2. Water, 0.1-40% by weight of abrasive grains, optionally a pH adjuster, optionally a biocide, a pH greater than 7, and 0.001-1% by weight of a composition of formula (I): 【Chemistry 8】 [In the formula, R １ , R ２ and R ３ is phenyl, benzyl and straight or branched chain C １ ~C ５ alkyl; － Br － , Cl － , I － , F － and OH － is an anion selected from the group consisting of 2. The chemical mechanical polishing composition of claim 1, comprising a quaternary ammonium compound having the formula:

3. Water, 5-25% by weight of an abrasive (wherein the abrasive is a colloidal silica abrasive), a pH adjuster, a biocide, a pH of 8-13, and 0.01-1% by weight of a compound of formula (I): 【Chemistry 9】 [In the formula, R １ , R ２ and R ３ is phenyl, benzyl and straight or branched chain C １ ~C ５ alkyl; － Br － , Cl － , I － , F － and OH － is an anion selected from the group consisting of 2. The chemical mechanical polishing composition of claim 1, comprising a quaternary ammonium compound having the formula:

4. 4. The chemical mechanical polishing composition of claim 3, wherein the pH adjuster is selected from the group consisting of potassium hydroxide, sodium hydroxide, ammonium salts, and mixtures thereof.

5. The quaternary ammonium compound has the formula (I): 【Chemistry 10】 [In the formula, R １ , R ２ and R ３ is C １ ~C ２ alkyl; － Br － , Cl － and OH － is an anion selected from the group consisting of The chemical mechanical polishing composition of claim 1 having the formula:

6. Providing a substrate comprising silicon oxide; Water, an abrasive, optionally a pH adjuster, optionally a biocide, a pH greater than 7, a composition of formula (I): 【Chemistry 11】 [In the formula, R １ , R ２ and R ３ is phenyl, benzyl and straight or branched chain C １ ~C ５ alkyl; － Br － , Cl － , I － , F － and OH － is an anion selected from the group consisting of providing a chemical mechanical polishing composition comprising a quaternary ammonium compound having the formula: Providing a chemical mechanical polishing pad having an abrasive surface; creating dynamic contact at an interface between the polishing surface of the chemical mechanical polishing pad and the substrate with a downforce of 3-35 kPa; and dispensing a chemical mechanical polishing composition onto the chemical mechanical polishing pad at or near an interface between the chemical mechanical polishing pad and the substrate; removing a portion of the silicon oxide from the substrate; A method for chemical mechanical polishing a substrate.

7. The quaternary ammonium compound has the formula (I): 【Chemistry 12】 [In the formula, R １ , R ２ and R ３ is C １ ~C ２ alkyl; － Br － , Cl － and OH － selected from the group consisting of The method of chemical mechanical polishing of claim 6, comprising:

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