A polishing composition with a wide removal rate selectivity ratio and use thereof

Abstract

The application discloses a polishing composition with wide removal rate selectivity ratio and application thereof, which takes nanometer silica gel with surface-fixed organic acid as a main polishing component, adds hydrophobic surfactant containing cocoyl and polyoxyethylene-polyoxypropylene hydrophilic copolymer as a selectivity ratio regulator, and further adds acrylic acid homopolymer with a weight average molecular weight of about 1000-200000 and its salt and acrylic acid copolymer formed by polymerization of acrylic acid monomer. The polishing composition comprises a selectivity ratio inhibitor composed of two surfactants and a water-soluble polymer, is green and low-toxic, can realize wider polishing selectivity of silicon nitride, silicon oxide and polysilicon material, and can effectively inhibit generation of polishing defects.

Description

Technical Field

[0001] This invention relates to the field of chemical mechanical polishing technology in integrated circuit manufacturing, and more particularly to a polishing composition with a wide removal rate selectivity and its application. Background Technology

[0002] In integrated circuits, polysilicon is the primary gate material, silicon oxide is the primary insulating material, and silicon nitride serves as a protective material to prevent damage to certain areas caused by ion implantation, diffusion, and etching. Chemical mechanical polishing (CMP) is required during gate fabrication. These three materials—polysilicon, silicon oxide, and silicon nitride—exhibit significant differences in chemical stability and hardness. Silicon nitride has the highest hardness and strongest chemical stability, followed by silicon oxide. During CMP, the removal rates of these three materials naturally differ significantly. Therefore, to achieve a specific selectivity ratio among their removal rates, chemical additives must be used for regulation. Furthermore, the polishing material surface is prone to polishing defects such as scratches, pitting, particle residue, and etching pits, which also require the addition of specific additives for improvement.

[0003] In chemical mechanical polishing (CMP), the selectivity of these three materials is a key research issue. From the perspective of basic physical properties, polycrystalline silicon has a hydrophobic surface, while silicon oxide and silicon nitride have hydrophilic surfaces. In addition, the isoelectric points (IEPs) of the three materials also differ significantly. For example, polycrystalline silicon has an IEP of 3.3, silicon oxide has an IEP of 2.5, and silicon nitride has an IEP of 8. These differences in basic physical properties are the premise for controlling the selectivity of the three materials in the polishing slurry system.

[0004] Currently, commonly used abrasives in polishing slurries include alumina, cerium oxide, and silicon oxide. Among these, nanoscale silica sol offers advantages such as fine particle size, minimal polishing damage, and surface cleanliness. Silica sol prepared using the sol-gel method also boasts advantages such as low metallic impurities and good stability, making it one of the main abrasives used in the industry for polishing materials such as silicon nitride, silicon oxide, and polycrystalline silicon. Furthermore, polishing slurries for these materials also contain selectivity modifiers, water-soluble polymers, rate accelerators, pH adjusters, and bactericides. Selectivity modifiers are crucial for altering the polishing selectivity among silicon nitride, silicon oxide, and polycrystalline silicon, while water-soluble polymers play a vital role in controlling polishing defects.

[0005] In the prior art, Korean patent KR20100014849A proposes adjusting the pH of the polishing composition to between 6 and 8, and adding aliphatic ammonium salt-type cationic surfactants such as octyltrimethylammonium bromide and decyltrimethylammonium bromide to the polishing composition to achieve a higher silicon nitride removal rate (compared to polycrystalline silicon and silicon oxide), control polishing defects, and improve the polished surface quality. However, these additives contain halogens, which are highly toxic and have limited applications.

[0006] Korean patent KR101340551B1 discloses a composition for selectively polishing silicon nitride, which uses cerium oxide as the abrasive and also contains components such as methacrylate copolymer and pyrimidine compounds. It achieves a high silicon nitride removal rate and good selectivity. However, although cerium oxide has a fast removal rate and good selectivity for silicon nitride, it is easy to form Si-O-Ce bonds between the two, making cleaning after polishing difficult. In addition, high-purity cerium oxide is also expensive.

[0007] Publicly available patents CN107075346A and CN114316900A propose using silica with surface-fixed organic acids and polyalkylene glycols in an acidic pH range to achieve high silicon nitride removal rates and high selectivity ratios of silicon nitride / silicon oxide and silicon nitride / polycrystalline silicon removal rates, with selectivity ratios between 20 and 30. Publicly available patent CN115141550A proposes a silica sol that has undergone cationic modification and aging treatment, with a surface silanol content of 0–2.5 hydroxyl groups / nm. 2 By adding substances such as polyvinyl alcohol, the selectivity ratio for silicon oxide / silicon nitride removal rates can be achieved between 0.7 and 2.0, and the selectivity ratio for polycrystalline silicon / (silicon nitride or silicon oxide) removal rates can be between 0.6 and 2.0. Although these patents achieve selectivity for the removal rates of these three materials within a certain range, their selectivity range is not wide enough to meet all practical application needs.

[0008] Overall, existing technologies are insufficient to solve the selectivity problem of removal rates for silicon nitride, silicon oxide, and polycrystalline silicon. Therefore, it is still necessary to make improvements based on existing technologies, such as by setting appropriate pH values ​​and adding specific selectivity modifiers and water-soluble polymers, so that the removal rates of the three materials can be controlled within a specific selectivity range while maintaining low polishing defects, thus overcoming the shortcomings of the existing technologies. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention provides a polishing composition with a wide removal rate selectivity. By adding two types of surfactants as selectivity regulators to a nano-silica body with organic acids fixed on its surface, the removal rate selectivity ratios of silicon nitride / polycrystalline silicon and silicon oxide / polycrystalline silicon can be controlled within specific ranges (e.g., the silicon nitride removal rate / polycrystalline silicon removal rate ratio is between 0.5 and 10.5; the silicon oxide removal rate / polycrystalline silicon removal rate ratio is between 0.4 and 4.20), while also maintaining low polishing defects, thus better suited for selective polishing of these three materials.

[0010] Another object of the present invention is to provide the application of this polishing composition in the chemical mechanical polishing of any two or more of the three materials: silicon nitride, silicon oxide, and polycrystalline silicon.

[0011] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0012] A polishing composition with a wide removal rate selectivity ratio uses nano-silica gel with organic acid immobilized on its surface as an abrasive, and further includes a coconut oil-based hydrophobic surfactant and a polyoxyethylene-polyoxypropylene hydrophilic copolymer as selectivity ratio modifiers.

[0013] In a preferred embodiment, the polishing composition comprises a nano-silica gel with an organic acid immobilized on its surface, a selectivity modifier, a water-soluble polymer, a rate accelerator, a pH adjuster, a bactericide, and deionized water. The selectivity modifier is composed of a hydrophobic surfactant containing coconut oil and a hydrophilic copolymer of polyethylene oxide and polypropylene oxide.

[0014] In a preferred embodiment, the polishing composition comprises the following components: 5-24 wt% of nano-silica gel with organic acid immobilized on its surface, 0.01-1 wt% of a selectivity modifier, 0.005-0.5 wt% of a water-soluble polymer, 0.05-3 wt% of a rate accelerator, 0.01-1 wt% of a pH adjuster, 0.005-0.2 wt% of a bactericide, with the balance being deionized water; wherein the selectivity modifier contains a coconut oil-based hydrophobic surfactant and a polyoxyethylene-polyoxypropylene hydrophilic copolymer in a weight ratio of 1:3 to 7:1.

[0015] In a more preferred embodiment, the polishing composition comprises the following components: 10-18 wt% of nano-silica gel with organic acid immobilized on its surface, 0.05-0.5 wt% of a selectivity modifier, 0.01-0.25 wt% of a water-soluble polymer, 0.1-1.5 wt% of a rate accelerator, 0.05-0.5 wt% of a pH adjuster, 0.01-0.1 wt% of a bactericide, and the balance being deionized water; wherein the selectivity modifier contains a coconut oil-based hydrophobic surfactant and a polyoxyethylene-polyoxypropylene hydrophilic copolymer in a weight ratio of 1:1 to 5:1.

[0016] In one specific embodiment, the surface is fixed with an organic acid nano-silica body, wherein the organic acid can be a carboxylic acid or a sulfonic acid, preferably a sulfonic acid, with an average primary particle size of 20-45 nm, an average secondary particle size of 50-90 nm, a zeta potential between -15 and -55 mV, and a mass concentration of 20 wt% to 30 wt%.

[0017] In one specific embodiment, the selectivity regulator contains a coconut oil-based hydrophobic surfactant with an HLB value greater than 3 and less than 10, such as selected from coconut oil monoethanolamide, cocoyl methyl monoethanolamide, cocoyl diethanolamide, cocoyl monoisopropanolamide, cocamidopropylamine oxide, cocamidopropyl dimethyl tertiary amine, cocamidopropyl-PG-dimethylammonium chloride sodium phosphate, cocamidopropyl betaine, cocamidopropyl betaine, cocamidopropyl hydroxysulfonyl betaine, coconut alcohol polyether, coconut oil polyamine, sucrose-cocoate, cocamidopropyl methylammonium chloride, cocamidopropyl trimethylammonium chloride, etc. At least one of the following: oil-based glucosinolate, sodium cocoyl hydroxyethyl sulfonate, sodium cocoyl hydroxyethyl imidazoline, sodium cocoamphoacetate, potassium cocoate, sodium cocoate, disodium cocoyl glutamate, potassium cocoyl glutamate, sodium cocoyl glycinate, potassium cocoyl glycinate, sodium cocoyl sarcosinate, sodium cocoyl aminopropionate, N-cocoyl-β-alanine derivative, sodium cocoyl methyl taurate, and potassium methyl cocoyl taurate; preferably, coconut oil monoethanolamide, cocamidopropylamine oxide, sucrose-cocoate, cocoyl trimethylammonium chloride, sodium cocoyl hydroxyethyl imidazoline, potassium cocoate, and potassium cocoyl glutamate.

[0018] In one specific implementation, the selected ratio regulator is a nonionic polyoxyethylene-polyoxypropylene hydrophilic copolymer, and its initiator can be a monohydric alcohol, propylene glycol, glycerol, alkylphenol, etc., including EO-PO block polyethers and random polyethers, with an HLB value greater than 10. For example, it can be selected from propylene glycol block polyether L35, propylene glycol block polyether F38, propylene glycol block polyether L43, propylene glycol block polyether L44, propylene glycol block polyether L45, propylene glycol block polyether L63, propylene glycol block polyether L64, propylene glycol block polyether F68, alkylphenol polyoxyethylene polyoxypropylene ether NPE-108, alkylphenol polyoxyethylene polyoxypropylene ether NPE-105, alkylphenol polyoxyethylene... At least one of the following: NPE-910 (polyoxypropylene ether), LPE-1200 (lauric acid random ether), BPE-1000 (butanol random ether), BPE-1500 (butanol random ether), BPE-2500 (butanol random ether), PPE-1500 (propylene glycol random ether), GPE-3000 (glycerol random ether), CPE-1500 (dodecyl alcohol random ether), and TPE-1000 (isotridecyl alcohol random ether); preferably, L35 (propylene glycol block ether), L43 (propylene glycol block ether), L45 (propylene glycol block ether), BPE-2500 (butanol random ether), PPE-1500 (propylene glycol random ether), and TPE-1000 (isotridecyl alcohol random ether).

[0019] In one specific embodiment, the water-soluble polymer is an acrylic acid homopolymer and its salts formed by polymerizing acrylic acid monomers, as well as an acrylic acid copolymer, with a weight-average molecular weight typically between about 1,000 and about 200,000, preferably between about 5,000 and about 50,000, and is selected, for example, from at least one of polyacrylic acid, polymethacrylic acid, poly(2-ethylacrylic acid), poly(2-propylacrylic acid), ammonium polyacrylate, sodium polyacrylate, sodium polymethacrylate, sodium polyhydroxyacrylate, polyacrylic acid-N-vinylpyrrolidone, polymethacrylic acid-N-vinylpyrrolidone, polyacrylic acid-b-poly(N-isopropylacrylamide), polyacrylic acid-b-polyacrylamide, polyacrylic acid-polylactic acid, polyethylene glycol-polyacrylic acid, polyethyleneimine-polyacrylic acid, polystyrene-b-polyacrylic acid, polystyrene-b-sodium polyacrylate, polyoxyethylene-b-polymethacrylic acid, and sodium polyphosphate-polyacrylic acid; preferably polyacrylic acid, polymethacrylic acid, ammonium polyacrylate, polyacrylic acid-polylactic acid, and polyethylene glycol-polyacrylic acid.

[0020] In one specific embodiment, the rate promoter is an organic ammonium and phosphonic acid substance, such as selected from at least one of ammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, (2-hydroxyethyl)trimethylammonium hydroxide, diethyldimethylammonium hydroxide, methyltriethylammonium hydroxide, benzyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, ethylenediaminetetramethylenephosphonic acid, hexamethylenediaminetetramethylenephosphonic acid, (3-aminophenyl)phosphonic acid, hydroxyethylidene diphosphonic acid, diethylenetriaminepentamethylenephosphonic acid, aminophosphonic acid, aminomethylphosphonic acid, aminoethylphosphonic acid, aminotrimethylenephosphonic acid, zoledronic acid, ethphosphonic acid, phenylphosphonic acid, and pamidronic acid; preferably ammonium hydroxide, tetramethylammonium hydroxide, ethylenediaminetetramethylenephosphonic acid, hydroxyethylidene diphosphonic acid, and aminotrimethylenephosphonic acid.

[0021] In one specific embodiment, the pH adjuster comprises inorganic and organic acids, such as those selected from at least one of nitric acid, nitrous acid, hydrochloric acid, phosphoric acid, phosphorous acid, hypophosphoric acid, pyrophosphoric acid, metaphosphoric acid, boric acid, sulfuric acid, carbonic acid, formic acid, furanoic acid, furanoic acid, phthalic acid, benzoic acid, acetic acid, furanoic acid, chloroacetic acid, dichloroacetic acid, citric acid, tartaric acid, lactic acid, malic acid, oxalic acid, maleic acid, itaconic acid, fumaric acid, glycolic acid, malonic acid, succinic acid, glutaric acid, methanesulfonic acid, p-toluenesulfonic acid, aminosulfonic acid, lysine, histidine, proline, alanine, glycine, valine, serine, tyrosine, glutamic acid, threonine, isoleucine, leucine, tryptophan, methionine, phenylalanine, aspartic acid, and cysteine; preferably phosphoric acid, malonic acid, histidine, or threonine. Preferably, the pH of the polishing composition is adjusted to 3-7.

[0022] In one specific embodiment, the bactericide is selected, for example, from at least one of polyhexamethylene guanidine hydrochloride, 1,2-benzisothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, 2-methyl-5-chloro-4-isothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 2-butyl-1,2-benzisothiazolin-3-one, 4,5-dichloro-2-octyl-4-isothiazolin-3-one, fluorinated diphenylacryloylmorpholine, dithiocyanomethane, 1,3-dihydroxymethyl-5,5-dimethylhydantoin, and 2,2-dibromo-2-cyanoacetamide; preferably 1,2-benzisothiazolin-3-one or 2-methyl-4-isothiazolin-3-one.

[0023] On the other hand, when the aforementioned polishing composition is used in the chemical mechanical polishing of any two or more of the three materials, namely silicon nitride, silicon oxide, and polycrystalline silicon, the ratio of the removal rate of silicon nitride to the removal rate of polycrystalline silicon is preferably between 0.5 and 10.5, and the ratio of the removal rate of silicon oxide to the removal rate of polycrystalline silicon is between 0.4 and 4.20.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] This invention uses nano-silica gel with organic acid fixed on its surface as an abrasive, which has the advantages of clean surface after polishing and less susceptibility to large particle scratches. Furthermore, the addition of a hydrophobic surfactant containing coconut oil and a hydrophilic copolymer of polyethylene oxide and polypropylene oxide as selectivity modifiers effectively adjusts the selectivity ratios of silicon nitride / polycrystalline silicon removal rates and silicon oxide / polycrystalline silicon removal rates. The further addition of acrylic homopolymer and its salt, as well as acrylic copolymer, effectively suppresses the generation of polishing defects, demonstrating significant advantages compared to existing technologies.

[0026] Compared with existing polishing slurries, the polishing composition of the present invention has an adjustable and wider selection ratio of removal rates, especially the ratio of silicon nitride removal rate to polycrystalline silicon removal rate is between 0.5 and 10.5, and the ratio of silicon oxide removal rate to polycrystalline silicon removal rate is between 0.4 and 4.20. Detailed Implementation

[0027] To better understand the technical solution of the present invention, the following embodiments will further illustrate the method provided by the present invention. However, the present invention is not limited to the listed embodiments, but should also include any other well-known modifications within the scope of the claims of the present invention.

[0028] A polishing composition with a wide removal rate selectivity ratio is disclosed. The polishing composition uses nano-silica gel with organic acid immobilized on its surface as the main polishing component, and adds a hydrophobic surfactant containing coconut oil and a hydrophilic copolymer of polyethylene oxide and polyoxypropylene. That is, based on the existing chemical mechanical polishing slurries for silicon nitride, silicon oxide and polycrystalline silicon materials with nano-silica gel with organic acid immobilized on its surface as abrasive, the addition of a hydrophobic surfactant containing coconut oil and a hydrophilic copolymer of polyethylene oxide and polyoxypropylene as selectivity ratio adjusters yields the polishing composition of the present invention.

[0029] The selectivity modifier contains a coconut oil-based hydrophobic surfactant. Its structure contains C8-C18 medium-short carbon chain coconut oil groups as the main hydrophobic groups, while amide groups, sulfonic acid groups, and amino acid groups are hydrophilic. Because the proportion of hydrophobic groups in its molecular structure is greater than that of hydrophilic groups, it exhibits overall hydrophobicity and has low solubility in water. The selectedivity modifier also contains a polyoxyethylene-polyoxypropylene hydrophilic copolymer, formed from ethylene oxide (EO) and propylene oxide (PO) under catalytic heating conditions. EO is hydrophilic, and PO is hydrophobic. Generally, when the proportion of EO in the EO-PO polymer exceeds 50%, it exhibits overall hydrophilicity with an HLB value greater than 10.

[0030] The selectivity modifier, composed of a coconut oil-based hydrophobic surfactant and a polyoxyethylene-polyoxypropylene hydrophilic copolymer, accounts for 0.01 to 1 wt% of the total mass of the polishing composition, for example, including but not limited to 0.01 wt%, 0.05%, 0.15 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, and 1 wt%.

[0031] The preferred weight ratio of the coconut oil-based hydrophobic surfactant to the polyoxyethylene-polyoxypropylene hydrophilic copolymer is 1:3 to 7:1, for example, including but not limited to 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, and 7:1. At this preferred mass ratio, on the one hand, the selection ratio adjuster regulates the hydrophobicity of the polishing slurry, achieving a specific polishing selectivity ratio of SiN / TEOS to Poly-Si; on the other hand, it also has a certain inhibitory effect on polishing defects including organic residues, abrasive residues, and scratches.

[0032] During the polishing process of silicon nitride, silicon oxide, and polycrystalline silicon materials, silicon nitride undergoes hydrolysis in water. However, this process is relatively weak, with a hydrolysis rate of only about 0.5%. The hydrolysis reaction of silicon nitride is significantly enhanced under acidic and alkaline conditions, due to the large amount of OH groups present under alkaline conditions. -This polarizes the Si-Si bonds, promoting hydroxylation on the silicon surface and significantly increasing the silicon removal rate. Therefore, to improve the selectivity of silicon nitride / polycrystalline silicon removal, the pH of the polishing composition should be set to neutral or slightly acidic. Under neutral or acidic conditions, the hydrolysis products of silicon nitride include silicon oxide-like substances such as SiO₂. - Compared to SiN, the hardness of these substances, such as SiOH, is significantly reduced, making them easier to remove during polishing. Adding some organic ammonium or phosphonic acid substances can complex with these hydrolysis products to promote the continuous hydrolysis reaction and accelerate the removal rate of silicon nitride.

[0033] Since silicon nitride and silicon oxide surfaces are hydrophilic, while polycrystalline silicon surfaces are hydrophobic, according to the principle described in the literature "Effect of Polysilicon Wettability on Polishing and Organic Defects during CMP," the attraction between hydrophobic surfaces is much greater than the interaction forces between hydrophilic and hydrophilic surfaces, and between hydrophobic and hydrophilic surfaces. When a hydrophobic surfactant is added to the polishing composition, it preferentially and tightly adsorbs onto the surface of the polycrystalline silicon material. This can reduce the chemical corrosion of the polycrystalline silicon material during CMP and also act as a lubricant to reduce mechanical friction on the polycrystalline silicon surface, while silicon nitride and silicon oxide are less affected. When a hydrophilic surfactant is added to the polishing composition, it relatively preferentially adsorbs onto the surfaces of silicon nitride and silicon oxide. This can control the removal rate of these two materials, reduce polishing defects to some extent, and also promote the dissolution of the hydrophobic surfactant.

[0034] In general, the selectivity regulator of this invention primarily utilizes a coconut oil-based hydrophobic surfactant, which adsorbs onto the polycrystalline silicon surface through hydrophobic-hydrophobic interactions to inhibit and regulate the removal rate of polycrystalline silicon. The polyoxyethylene-polyoxypropylene hydrophilic copolymer primarily adsorbs onto the surfaces of silicon nitride and silicon oxide, thereby regulating the removal rate of the dielectric material and improving its polishing quality. By adjusting the ratio of these two components, the selectivity ratio of silicon nitride / polycrystalline silicon and silicon oxide / polycrystalline silicon removal rates can be adjusted.

[0035] The particle size of the nano-silica gel with organic acid fixed on its surface is 50-90 nm, including but not limited to 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, and 90 nm. The mass concentration of the silica sol is 20-30 wt%, including but not limited to 20 wt%, 25 wt%, and 30 wt%. For example, the nano-silica sol abrasive used can be from Fuso's PL series products or related products from Nissan and DuPont. The "50-90 nm" refers to the average secondary particle size, and there is no particular limitation on the average primary particle size of the nano-silica gel with organic acid fixed on its surface. Preferably, it is 20 nm or more, more preferably 25 nm or more, and even more preferably 30 nm or more. In addition, the average primary particle size of the nano-silica gel with organic acid fixed on its surface in the polishing composition is preferably 45 nm or less, and even more preferably 40 nm or less. Therefore, from the perspective of controlling the polishing rate and polishing defects, the average primary particle size of the nano-silica body with organic acid immobilized on the surface is preferably above 20 nm and below 40 nm. It should be noted that the test method for the average secondary particle size of the nano-silica body with organic acid immobilized on the surface is the laser particle size analyzer method, and the test method for the average primary particle size is the BET method.

[0036] Regarding "nano silica sol with organic acid fixed on its surface", please refer to the published patent CN114316900A. In essence, organic acid is grafted onto the surface of silica sol in a chemical bonding manner, and the two are connected in the form of covalent bonds. There are no particular restrictions on the preparation method of silica sol, which can be the elemental silicon method, ion exchange method, or sol-gel method. From the perspective of controlling impurities, the sol-gel method is preferred. There are no particular restrictions on the type of organic acid, which can be carboxylic acid and sulfonic acid, with sulfonic acid being preferred.

[0037] There are no particular limitations on the methods for grafting organic acids onto the surface of silica sol, such as grafting alkyl or mercapto groups onto the silica sol surface and then oxidizing them to carboxylic acids or sulfonic acids. Specifically, a method for fixing carboxylic acids onto the silica sol surface as organic acids can be described in "Novel Silane Coupling Agents Containing a Photolabile 2-Nitrobenzyl Ester for Introduction of a Carboxy Group on the Surface of SilicaGel", Chemistry Letters, 3, 228-229 (2000). Specifically, this can be achieved by first fixing the silane coupling agent 2-nitrobenzyl ester onto the silica sol surface (the methyl group of 2-nitrobenzyl ester hydrolyzes to form Si-OH, which dehydrates with the silanol groups on the silica sol surface to form Si-O-Si bonds), and then removing the nitrobenzyl group of the silane coupling agent by light irradiation to form a carboxyl group, thus obtaining a nano-silica gel with carboxylic acid fixed on its surface. Another example is the specific method of fixing sulfonic acid as an organic acid onto the surface of silica sol. For instance, it can be carried out using the method described in "Sulfonic acid-functionalized silica through quantitative oxidation of thiol groups", Chem. Commun. 246-247 (2003). Specifically, a silane coupling agent containing thiol groups (such as MPMDMS, MPTMS, PTMS) can be first fixed onto the surface of silica sol, and then the thiol groups can be oxidized to sulfonic acid groups with H2O2 to obtain nano silica sol with sulfonic acid fixed on the surface.

[0038] In this invention, the nano-silica gel with organic acid immobilized on its surface carries a negative charge, i.e., a negative zeta potential, measured in mV. From the perspective of improving the polishing silicon nitride removal rate and preventing large particle formation, it is preferable that the absolute value of its zeta potential is 15 mV or higher, more preferably 20 mV or higher, and even more preferably 25 mV or higher. From the perspective of controlling the polishing silicon oxide removal rate and polycrystalline silicon removal rate, it is preferable that the absolute value of its zeta potential is 55 mV or lower, more preferably 50 mV or lower, and even more preferably 45 mV or lower. Therefore, from the perspective of controlling the polishing rate and selectivity, the absolute value of the zeta potential of the nano-silica gel with organic acid immobilized on its surface is preferably 25 mV or higher and 45 mV or lower.

[0039] The hydrophobic surfactant containing a coconut oil group in the selectivity ratio adjuster has an HLB value greater than 3 and less than 10, and is selected from, for example, coconut oil monoethanolamide, cocoyl methyl monoethanolamide, cocoyl diethanolamide, cocoyl monoisopropanolamide, cocamidopropylamine oxide, cocamidopropyl dimethyl tertiary amine, cocamidopropyl-PG-dimethylammonium chloride sodium phosphate, cocamidopropyl betaine, cocamidopropyl betaine, cocamidopropyl hydroxysulfonyl betaine, coconut alcohol polyether, coconut polyamine, sucrose-cocoate, cocamidopropyl methylammonium chloride, cocamidopropyl trimethylammonium chloride, cocamidopropyl glucoside, cocamidopropyl hydroxyethyl sulfonate sodium, and cocamidopropyl hydroxyethyl sulfonate. At least one of the following: ethyl imidazoline, sodium cocoamphoacetate, potassium cocoate, sodium cocoate, disodium cocoyl glutamate, potassium cocoyl glutamate, sodium cocoyl glycinate, potassium cocoyl glycinate, sodium cocoyl sarcosinate, sodium cocoyl aminopropionate, N-cocoyl-β-alanine derivative, sodium cocoyl methyl taurate, and potassium methyl cocoyl taurate, for example, any one, any combination of two or more of the above-mentioned hydrophobic surfactants containing coconut oil groups, preferably coconut oil monoethanolamide, cocamidopropylamine oxide, sucrose-cocoate, cocoyl trimethylammonium chloride, cocoyl hydroxyethyl imidazoline, potassium cocoate, and potassium cocoyl glutamate.

[0040] The hydrophilic copolymer of polyethylene oxide and polypropylene oxide in the aforementioned selectivity modifier is nonionic. Its initiator can be a monohydric alcohol, propylene glycol, glycerol, or alkylphenol, including EO-PO block ethers and random ethers, with an HLB value greater than 10. Examples include propylene glycol block ether L35, propylene glycol block ether F38, propylene glycol block ether L43, propylene glycol block ether L44, propylene glycol block ether L45, propylene glycol block ether L63, propylene glycol block ether L64, propylene glycol block ether F68, alkylphenol polyoxyethylene polyoxypropylene ether NPE-108, alkylphenol polyoxyethylene polyoxypropylene ether NPE-105, alkylphenol polyoxyethylene polyoxypropylene ether NPE-910, and lauric acid random ether L... At least one of PE-1200, butanol random polyether BPE-1000, butanol random polyether BPE-1500, butanol random polyether BPE-2500, propylene glycol random polyether PPE-1500, glycerol random polyether GPE-3000, dodecyl alcohol random polyether CPE-1500, and isotridecyl alcohol random polyether TPE-1000, for example, containing any one, any two or more of the above-mentioned hydrophilic copolymers of polyoxyethylene-polyoxypropylene, preferably propylene glycol block polyether L35, propylene glycol block polyether L43, propylene glycol block polyether L45, butanol random polyether BPE-2500, propylene glycol random polyether PPE-1500, and isotridecyl alcohol random polyether TPE-1000.

[0041] In addition to the above-mentioned three main components—nano silica gel bodies with organic acids fixed on their surfaces as abrasives, and containing coconut oil-based hydrophobic surfactants and polyoxyethylene-polyoxypropylene hydrophilic copolymers—this invention does not limit the addition of any other additives to the polishing composition. It is applicable to various conventional silicon nitride, silicon oxide, and polycrystalline silicon chemical mechanical polishing slurry systems. Furthermore, depending on the need to control the selectivity of silicon nitride / polycrystalline silicon and silicon oxide / polycrystalline silicon removal rates, improve the polished surface quality, or enhance the storage stability of the composition, those skilled in the art can arbitrarily select one or more water-soluble polymers, rate accelerators, pH adjusters, and bactericides to add to the polishing composition.

[0042] The water-soluble polymers mentioned above include homopolymers of acrylic acid formed by polymerization of acrylic acid monomers, their salts, and acrylic acid copolymers, with a weight-average molecular weight typically between about 1,000 and about 200,000, and are selected, for example, from polyacrylic acid, polymethacrylic acid, poly(2-ethylacrylic acid), poly(2-propylacrylic acid), ammonium polyacrylate, sodium polyacrylate, sodium polymethacrylate, sodium polyhydroxyacrylate, polyacrylic acid-N-vinylpyrrolidone, polymethacrylic acid-N-vinylpyrrolidone, and polyacrylic acid-b-poly(N-isopropylacrylamide). The water-soluble polymer comprises at least one of the following: polyacrylic acid-b-polyacrylamide, polyacrylic acid-polylactic acid, polyethylene glycol-polyacrylic acid, polyethyleneimine-polyacrylic acid, polystyrene-b-polyacrylic acid, sodium polystyrene-b-polyacrylate, polyoxyethylene-b-polymethacrylic acid, and sodium polyphosphate-polyacrylic acid; or any combination of any two or more of the above-mentioned water-soluble polymers, preferably polyacrylic acid, polymethacrylic acid, ammonium polyacrylate, polyacrylic acid-polylactic acid, or polyethylene glycol-polyacrylic acid, and preferably has a weight-average molecular weight of about 5,000 to about 50,000. The water-soluble polymer has a long carbon chain and contains a large number of carboxyl groups in its molecular structure, which can form a three-dimensional and dense film on the surface of the polishing material, and can inhibit the generation of polishing defects such as scratches, pits, and etching during the polishing process.

[0043] The rate accelerator includes organic ammonium compounds and phosphonic acid substances, such as those selected from at least one of ammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, (2-hydroxyethyl)trimethylammonium hydroxide, diethyldimethylammonium hydroxide, methyltriethylammonium hydroxide, benzyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, ethylenediaminetetramethylenephosphonic acid, hexamethylenediaminetetramethylenephosphonic acid, (3-aminophenyl)phosphonic acid, hydroxyethylidene diphosphonic acid, diethylenetriaminepentamethylenephosphonic acid, aminophosphonic acid, aminomethylphosphonic acid, aminoethylphosphonic acid, aminotrimethylenephosphonic acid, zoledronic acid, ethphosphonic acid, phenylphosphonic acid, and pamidronic acid, for example, any one, any combination of two or more of the above-mentioned rate accelerators, preferably ammonium hydroxide, tetramethylammonium hydroxide, ethylenediaminetetramethylenephosphonic acid, hydroxyethylidene diphosphonic acid, and aminotrimethylenephosphonic acid. The rate accelerator can react with the hydrolysis products of silicon nitride, silicon oxide, and polycrystalline silicon, such as SiOH and SiO₂. - A complexation reaction occurs, which promotes the chemical corrosion during the polishing process.

[0044] The pH adjuster includes inorganic acids and organic acids, such as those selected from at least one of nitric acid, nitrous acid, hydrochloric acid, phosphoric acid, phosphorous acid, hypophosphoric acid, pyrophosphoric acid, metaphosphoric acid, boric acid, sulfuric acid, carbonic acid, formic acid, furanoic acid, furanoic acid, phthalic acid, benzoic acid, acetic acid, furanoic acid, chloroacetic acid, dichloroacetic acid, citric acid, tartaric acid, lactic acid, malic acid, oxalic acid, maleic acid, itaconic acid, fumaric acid, glycolic acid, malonic acid, succinic acid, glutaric acid, methanesulfonic acid, p-toluenesulfonic acid, aminosulfonic acid, lysine, histidine, proline, alanine, glycine, valine, serine, tyrosine, glutamic acid, threonine, isoleucine, leucine, tryptophan, methionine, phenylalanine, aspartic acid, and cysteine, for example, any one, any combination of two or more of the above-mentioned pH adjusters, preferably phosphoric acid, malonic acid, histidine, or threonine. Preferably, the pH of the polishing composition is adjusted to 3-7; more preferably, the pH of the polishing composition is adjusted to 4-6. The pH adjuster adjusts the pH of the polishing composition to neutral or slightly acidic by controlling the OH groups in the polishing system. - The concentration of silicon nitride, silicon oxide and polysilicon is adjusted to control the removal rate of polysilicon and regulate the selection ratio of removal rates of silicon nitride, silicon oxide and polysilicon.

[0045] The bactericide is selected from at least one of the following: polyhexamethylene guanidine hydrochloride, 1,2-benzisothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, 2-methyl-5-chloro-4-isothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 2-butyl-1,2-benzisothiazolin-3-one, 4,5-dichloro-2-octyl-4-isothiazolin-3-one, fluorinated diphenylacryloylmorpholine, dithiocyanomethane, 1,3-dihydroxymethyl-5,5-dimethylhydantoin, and 2,2-dibromo-2-cyanoacetamide; for example, any one, any two or more of the above bactericides, preferably 1,2-benzisothiazolin-3-one or 2-methyl-4-isothiazolin-3-one. The antibacterial agent is used to inhibit the growth of bacteria and fungi in the polishing fluid and prevent the aging and failure of the polishing fluid caused by the metabolic products of microorganisms.

[0046] In one specific embodiment, the composition is made from the components in the following proportions:

[0047]

[0048] The polishing composition has a pH value of 3 to 7, including but not limited to 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, and 7, preferably 4 to 6.

[0049] The selected ratio regulator contains a coconut oil-based hydrophobic surfactant and a polyoxyethylene-polyoxypropylene hydrophilic copolymer in a weight ratio of 1:3 to 7:1, for example, including but not limited to 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, preferably 1:1 to 5:1.

[0050] The preparation method of the polishing composition of the present invention can be, for example, by mixing the components according to those known in the art. Specifically, for example, a method for preparing a polishing composition includes the step of mixing a selectivity modifier with nano-silica gel on the surface with organic acid and other additives.

[0051] In a preferred embodiment, the rate accelerator, pH adjuster, water-soluble polymer, polyoxyethylene-polyoxypropylene hydrophilic copolymer, coconut oil-based hydrophobic surfactant, and bactericide described in this invention are first added to deionized water and thoroughly mixed and dispersed to form the chemical auxiliaries of the composition.

[0052] Then, chemical additives are added to the nano silica gel body with organic acids fixed on the surface, and after thorough stirring and dispersion, the polishing composition of the present invention is formed. The dispersion means in this process include, but are not limited to, any one or more of mechanical stirring, ultrasonic dispersion, and magnetic stirring.

[0053] The present invention will be further explained and illustrated below through more specific embodiments, but these do not constitute any limitation.

[0054] In the following embodiments, the equipment and parameters for wafer polishing testing are as follows;

[0055] Polishing machine: Ebara F-REX200 polishing machine

[0056] Polishing pad: IC1010 type

[0057] Polishing materials:

[0058] 1) 200mm SiN wafer (low-pressure chemical vapor deposition SiN thickness) )

[0059] 2) 200mm TEOS wafer (Physical Vapor Deposition TEOS Thickness) )

[0060] 3) 200mm Poly-Si wafer (low-pressure chemical vapor deposition Poly-Si thickness) )

[0061] Polishing disc speed: 81 / 80 rpm

[0062] Polishing pressure: 2.0 psi

[0063] Flow rate: 0.5 L / min

[0064] Polishing time: 1 min

[0065] Polishing temperature: 30~32℃

[0066] The polishing fluid used is filtered and then delivered to the polishing pad by a peristaltic pump. After each polishing, the polishing pad is dressed and maintained using a diamond dresser. Pre-polishing is performed before each polishing.

[0067] Removal Rate Test: The thicknesses of SiN, TEOS, and Poly-Si films before and after polishing were measured using a non-metallic film thickness gauge (TohoSpec 3100). The removal rate (MRR) was calculated based on the polishing time.

[0068] Polishing defect test: The polished SiN wafers were scanned and tested using KLA-Tencor SP2, and the total number of defects on the surface was counted as Defect count / each.

[0069] Unless otherwise specified, the chemical reagents used in the embodiments and comparative examples of this invention can be purchased through commercial channels.

[0070] Preparation example:

[0071] 0.2 g of 3-mercaptopropyltrimethoxysilane (MPTMS) was dropped into 100 g of PL-2 silica sol (20% solids content, average particle size 50 nm), and magnetically stirred for 30 min. Then, it was left at room temperature for 24 h. Next, 300 ml of 30% H2O2 solution was poured in and stirred at 60 °C for 1 h (so that the mercapto groups on the surface of the silica sol were completely oxidized to sulfonic acid groups). This prepared a nano silica sphere with 20% solids content and sulfonic acid fixed on the surface, namely abrasive A.

[0072] Abrasive B and abrasive C were prepared from silica sol with 30% solid content and a particle size of 70 nm or 30% solid content and a particle size of 90 nm using the same method described above.

[0073] Example 1

[0074] 1g tetramethylammonium hydroxide, 0.2g phosphoric acid, 0.1g polyacrylic acid (Mw1000), 0.15g propylene glycol block polyether L35, 0.05g coconut oil monoethanolamide, 0.05g 1,2-benzisothiazolin-3-one, and 0.05g 2-methyl-4-isothiazolin-3-one were added to 300g of deionized water and stirred until homogeneous. Then, while stirring, the solution was added to 500g of nano-silica gel (20% solids content, 50nm particle size) with sulfonic acid fixed on its surface. Deionized water was added until the total mass of the dispersion was 2kg. The mixture was stirred at high speed for 30min, encapsulated, and the pH of the dispersion was 7, with a Zeta potential of -55mV.

[0075] Examples 2-10 and Comparative Examples 1-3 were prepared according to the above method. The components, specific contents, pH and Zeta potential of the examples and comparative examples are shown in Table 1 below.

[0076] Table 1. Components, contents, pH and Zeta potential of the examples and comparative examples

[0077]

[0078]

[0079] The specific details of abrasives A, B, and C in Table 1 above are as follows:

[0080] Abrasive A---Nano silica gel with sulfonic acid fixed on the surface, 20% solid content, particle size 50nm;

[0081] Abrasive B---Nano silica gel with sulfonic acid fixed on the surface, 30% solid content, particle size 70nm;

[0082] Abrasive C---Nano silica gel with sulfonic acid fixed on the surface, 30% solids content, 90nm particle size

[0083] The polishing compositions of each embodiment and comparative example were diluted at a mass ratio of 1:9 and then polishing tests were performed. The polishing test results are shown in Table 2 below:

[0084] Table 2 Polishing Test Results

[0085]

[0086]

[0087] Comparing Comparative Example 1 and Example 5 in Table 2 above, it can be found that compared with the examples, the removal rate of Poly-Si in the comparative examples increased significantly, the removal rates of SiN and TEOS increased slightly, and the selectivity of silicon nitride / polycrystalline silicon and silicon oxide / polycrystalline silicon removal rates decreased. The polishing defects in the comparative examples also increased significantly. This indicates that the selectivity regulator composed of a hydrophobic surfactant containing coconut oil and a hydrophilic copolymer of polyethylene oxide and polypropylene oxide can effectively adjust the selectivity ratio of silicon nitride, silicon oxide, and polycrystalline silicon removal rates, thereby accurately eliminating the height difference between the dielectric material and polycrystalline silicon. On the other hand, it can also play a certain protective role for the polishing material and reduce the defects generated during polishing.

[0088] Comparing Comparative Examples 2 and 3 with Example 5 in Table 2, Comparative Example 2, which only added a coconut oil-based hydrophobic surfactant as the selectivity modifier, shows that compared to Example 5, the removal rates of SiN and TEOS in Comparative Example 2 are slightly increased, as is the removal rate of Poly-Si, and the number of polishing defects is significantly increased. This indicates that even without the addition of the polyoxyethylene-polyoxypropylene hydrophilic copolymer, the inhibitory effect of the hydrophobic surfactant on the polycrystalline silicon removal rate is reduced to some extent. This may be because its dissolution and dispersion in the system are insufficient, resulting in a decrease in its adsorption and protective effect on the polycrystalline silicon surface. Comparative Example 3, which only added a polyoxyethylene-polyoxypropylene hydrophilic copolymer as the selectivity modifier, shows that compared to Example 5, the removal rate of polycrystalline silicon in Comparative Example 3 is significantly increased, the selectivity of silicon nitride / polycrystalline silicon and silicon oxide / polycrystalline silicon removal rates is reduced, and the number of polishing defects is also significantly increased. By comparison, it can be found that the selection ratio of the polishing composition to the coconut oil-based hydrophobic surfactant and the polyoxyethylene-polyoxypropylene hydrophilic copolymer can play a synergistic role. When the two are in the right ratio, they can accurately eliminate the height difference between SiN, TEOS and polycrystalline silicon, and can also effectively reduce polishing defects to a certain extent. The reason may be that when the two are present at the same time, the hydrophobic surfactant is more fully dissolved and dispersed, and the overall hydrophilicity and hydrophobicity of the polishing composition can be better controlled within a reasonable range.

[0089] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as limiting the present invention. Those skilled in the art will understand that modifications or adjustments can be made to the present invention based on the teachings of this specification. These modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. A polishing composition with a wide removal rate selectivity, characterized in that, The product includes nano-silica gel with organic acids immobilized on its surface, a selectivity regulator, a water-soluble polymer, a rate accelerator, a pH adjuster, a bactericide, and deionized water; the selectivity regulator is a hydrophobic surfactant containing coconut oil and a hydrophilic copolymer of polyethylene oxide and polypropylene oxide. The contents of each component are as follows: 5-24 wt% of nano-silica gel with organic acid immobilized on the surface, 0.01-1 wt% of selectivity regulator, 0.005-0.5 wt% of water-soluble polymer, 0.05-3 wt% of rate promoter, 0.01-1 wt% of pH adjuster, 0.005-0.2 wt% of bactericide, and the balance is deionized water; The selectivity ratio regulator contains a coconut oil-based hydrophobic surfactant and a polyoxyethylene-polyoxypropylene hydrophilic copolymer in a mass ratio of 1:3 to 7:

1.

2. The polishing composition according to claim 1, characterized in that, The contents of each component are as follows: 10-18 wt% of nano-silica gel with organic acid fixed on the surface, 0.05-0.5 wt% of selectivity regulator, 0.01-0.25 wt% of water-soluble polymer, 0.1-1.5 wt% of rate promoter, 0.05-0.5 wt% of pH adjuster, 0.01-0.1 wt% of bactericide, and the balance is deionized water.

3. The polishing composition according to claim 1, characterized in that, The selectivity ratio regulator contains a coconut oil-based hydrophobic surfactant and a polyoxyethylene-polyoxypropylene hydrophilic copolymer in a mass ratio of 1:1 to 5:

1.

4. The polishing composition according to claim 1 or 2, characterized in that, The organic acids fixed on the surface of the nano silica gel are carboxylic acids or sulfonic acids.

5. The polishing composition according to claim 4, characterized in that, The organic acid in the nano-silica gel with organic acid fixed on its surface is sulfonic acid.

6. The polishing composition according to claim 4, characterized in that, The nano-silica gel with organic acid fixed on its surface has a negative charge, and the absolute value of the zeta potential is between 15 and 55 mV.

7. The polishing composition according to claim 6, characterized in that, The absolute value of the zeta potential is between 25 and 45 mV.

8. The polishing composition according to claim 1 or 2, characterized in that, The average primary particle size of the nano-silica body with organic acid fixed on its surface is 20 nm or more and 45 nm or less; the average secondary particle size is 50 nm or more and 90 nm or less; and the mass concentration is 20 wt% to 30 wt%.

9. The polishing composition according to claim 1, characterized in that, The hydrophobic surfactant containing coconut oil has an HLB value greater than 3 and less than 10.

10. The polishing composition according to claim 9, characterized in that, The hydrophobic surfactant containing coconut oil is selected from coconut oil monoethanolamide, cocoyl methyl monoethanolamide, cocoyl diethanolamide, cocoyl monoisopropanolamide, cocamidopropylamine oxide, cocamidopropyl dimethyl tertiary amine, cocamidopropyl-PG-dimethylammonium chloride sodium phosphate, cocamidopropyl betaine, cocamidopropyl betaine, cocamidopropyl hydroxysulfonyl betaine, coconut oil alcohol polyether, coconut oil polyamine, sucrose-cocoate, and cocamidopropyl methyl chloride. Ammonium chloride, cocotrimethylammonium chloride, cocoglucoside, sodium cocohydroxyethylsulfonate, sodium cocohydroxyethyl imidazoline, sodium cocoamphoacetate, potassium cocoate, sodium cocoate, disodium cocoylglutamate, potassium cocoylglutamate, sodium cocoyl glycinate, potassium cocoyl glycinate, sodium cocoyl sarcosinate, sodium cocoaminopropionate, N-cocoalkyl-β-alanine derivative, sodium cocoyl methyl taurate, and potassium methyl cocoyl taurate.

11. The polishing composition according to claim 1, characterized in that, The polyoxyethylene-polyoxypropylene hydrophilic copolymer is an EO-PO block polyether or random polyether with an HLB value greater than 10.

12. The polishing composition according to claim 11, characterized in that, The polyoxyethylene-polyoxypropylene hydrophilic copolymer is selected from propylene glycol block polyether L35, propylene glycol block polyether F38, propylene glycol block polyether L43, propylene glycol block polyether L44, propylene glycol block polyether L45, propylene glycol block polyether L63, propylene glycol block polyether L64, propylene glycol block polyether F68, alkylphenol polyoxyethylene polyoxypropylene ether NPE-108, alkylphenol polyoxyethylene polyoxypropylene ether NPE-105, and alkylphenol. At least one of the following: polyoxyethylene polyoxypropylene ether NPE-910, lauric acid random polyether LPE-1200, butanol random polyether BPE-1000, butanol random polyether BPE-1500, butanol random polyether BPE-2500, propylene glycol random polyether PPE-1500, glycerol random polyether GPE-3000, dodecyl alcohol random polyether CPE-1500, and isomeric tridecyl alcohol random polyether TPE-1000.

13. The polishing composition according to claim 1 or 2, characterized in that, The water-soluble polymer is an acrylic homopolymer formed by polymerizing acrylic monomers, its salt, or an acrylic copolymer.

14. The polishing composition according to claim 13, characterized in that, The water-soluble polymer is selected from at least one of polyacrylic acid, polymethacrylic acid, poly(2-ethylacrylic acid), poly(2-propylacrylic acid), ammonium polyacrylate, sodium polyacrylate, sodium polymethacrylate, sodium polyhydroxyacrylate, polyacrylic acid-N-vinylpyrrolidone, polymethacrylate-N-vinylpyrrolidone, polyacrylic acid-b-poly(N-isopropylacrylamide), polyacrylic acid-b-polyacrylamide, polyacrylic acid-polylactic acid, polyethylene glycol-polyacrylic acid, polyethyleneimine-polyacrylic acid, polystyrene-b-polyacrylic acid, polystyrene-b-sodium polyacrylate, polyoxyethylene-b-polymethacrylic acid, and sodium polyphosphate-polyacrylic acid.

15. The polishing composition according to claim 14, characterized in that, The weight-average molecular weight of the water-soluble polymer is 1,000 to 200,000.

16. The polishing composition according to claim 15, characterized in that, The weight-average molecular weight of the water-soluble polymer is 5,000 to 50,000.

17. The polishing composition according to claim 1 or 2, characterized in that, The rate accelerator is an organic ammonium or phosphonic acid substance.

18. The polishing composition according to claim 17, characterized in that, The rate accelerator is selected from at least one of ammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, (2-hydroxyethyl)trimethylammonium hydroxide, diethyldimethylammonium hydroxide, methyltriethylammonium hydroxide, benzyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, ethylenediaminetetramethylenephosphonic acid, hexamethylenediaminetetramethylenephosphonic acid, (3-aminophenyl)phosphonic acid, hydroxyethylidene diphosphonic acid, diethylenetriaminepentamethylenephosphonic acid, aminophosphonic acid, aminomethylphosphonic acid, aminoethylphosphonic acid, aminotrimethylenephosphonic acid, zoledronic acid, ethphosphonic acid, phenylphosphonic acid, and pamidronic acid.

19. The polishing composition according to claim 1 or 2, characterized in that, The pH adjuster is selected from at least one of nitric acid, nitrous acid, hydrochloric acid, phosphoric acid, phosphorous acid, hypophosphoric acid, pyrophosphoric acid, metaphosphoric acid, boric acid, sulfuric acid, carbonic acid, formic acid, furanoic acid, furanoic acid, phthalic acid, benzoic acid, acetic acid, furanoic acid, chloroacetic acid, dichloroacetic acid, citric acid, tartaric acid, lactic acid, malic acid, oxalic acid, maleic acid, itaconic acid, fumaric acid, glycolic acid, malonic acid, succinic acid, glutaric acid, methanesulfonic acid, p-toluenesulfonic acid, aminosulfonic acid, lysine, histidine, proline, alanine, glycine, valine, serine, tyrosine, glutamic acid, threonine, isoleucine, leucine, tryptophan, methionine, phenylalanine, aspartic acid, and cysteine.

20. The polishing composition according to claim 19, characterized in that, The pH value of the polishing composition is between 3 and 7.

21. The polishing composition according to claim 1 or 2, characterized in that, The bactericide is selected from at least one of polyhexamethylene guanidine hydrochloride, 1,2-benzisothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, 2-methyl-5-chloro-4-isothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 2-butyl-1,2-benzisothiazolin-3-one, 4,5-dichloro-2-octyl-4-isothiazolin-3-one, fluorinated diphenylacryloylmorpholine, dithiocyanomethane, 1,3-dihydroxymethyl-5,5-dimethylhydantoin, and 2,2-dibromo-2-cyanoacetamide.

22. The use of the polishing composition with a wide removal rate selectivity according to any one of claims 1 to 21 in the chemical mechanical polishing of at least two of silicon nitride, silicon oxide and polysilicon in the manufacture of integrated circuits.

23. The application according to claim 22, characterized in that, The ratio of silicon nitride removal rate to polycrystalline silicon removal rate is between 0.5 and 10.5, while the ratio of silicon oxide removal rate to polycrystalline silicon removal rate is between 0.4 and 4.20.

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