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CN-121975440-A - High-stability acidic chemical mechanical polishing solution and preparation method and application thereof

CN121975440ACN 121975440 ACN121975440 ACN 121975440ACN-121975440-A

Abstract

The invention provides a high-stability acidic chemical mechanical polishing solution, a preparation method and application thereof, wherein the polishing solution comprises, by mass, 5-30wt% of a silicon oxide abrasive, 0.01wt% to 1wt% of a modifier, 0.01wt% to 2wt% of a surfactant, 0.01wt% to 1wt% of a regulator, and the balance of a pH regulator and water, the pH regulator enables the pH value of the polishing solution to be 3-5, the modifier is an organic ammonium salt and/or an organic amine, the surfactant is compounded by alkyl sulfobetaine and betaine according to a mass ratio of 1:0.1-5, and the regulator is a weak acid. According to the invention, the acid chemical mechanical polishing solution has high stability and high polishing rate at pH=3-5 by adding the modifier, the compound surfactant and the special weak acid regulator.

Inventors

  • Hui Hongye
  • SUN TIANYU
  • WAN XUJUN
  • ZHU HAIQING

Assignees

  • 宁波平恒电子材料有限公司

Dates

Publication Date
20260505
Application Date
20260129

Claims (10)

  1. 1. A high-stability acidic chemical mechanical polishing solution is characterized by comprising, by mass, 5-30% of a silicon oxide abrasive, 0.01-1% of a modifier, 0.01-2% of a surfactant, 0.01-1% of a regulator, and the balance of a pH regulator and water, wherein the pH regulator enables the pH value of the polishing solution to be 3-5, the modifier is an organic ammonium salt and/or an organic amine, the surfactant is obtained by compounding alkyl sulfobetaine and betaine according to a mass ratio of 1:0.1-5, and the regulator is a weak acid.
  2. 2. The polishing liquid according to claim 1, wherein the modifier is any one or more selected from the group consisting of tetrabutylammonium hydroxide, tetrapropylammonium hydroxide, dihexyltriamine, trihexylamine, dicyclohexylamine, spermine, spermidine.
  3. 3. The polishing liquid according to claim 1, wherein the alkyl sulfobetaine is any one or more selected from the group consisting of thiobetaine 8, thiobetaine 10, thiobetaine 12, octadecyl sulfobetaine, lauroyl propyl hydroxysulfonic acid betaine, and cocoamidohydroxysulfobetaine.
  4. 4. The polishing liquid according to claim 1, wherein the regulator is any one or more selected from acetic acid, citric acid and maleic acid.
  5. 5. The polishing liquid according to claim 1, wherein the pH adjustor is one or more selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and acetic acid.
  6. 6. The polishing liquid according to claim 1, wherein the silica abrasive is any one or two selected from spherical silica and curved silica; And/or the particle size of the silicon oxide is 30-100 nm.
  7. 7. A method for preparing the polishing liquid according to any one of claims 1 to 6, wherein the method comprises the steps of mixing and stirring a surfactant, an abrasive and part of water, adjusting the pH of the solution to 3 to 5 to obtain liquid A, mixing and stirring a modifier, an adjusting agent and the rest of water, adjusting the pH of the solution to 3 to 5 to obtain liquid B, and mixing the liquid A and the liquid B to obtain the polishing liquid.
  8. 8. The preparation method of claim 7, wherein the stirring speed in the preparation process of the liquid A and the liquid B is 100-300 r/min; And/or stirring for 10-30 min in the preparation process of the liquid A and the liquid B.
  9. 9. Use of the polishing liquid according to any one of claims 1 to 6 for polishing a silicon oxide dielectric layer.
  10. 10. The alkyl sulfobetaine and betaine are compounded to be used as a surfactant, and are used for reducing the surface roughness of the polished silicon oxide wafer.

Description

High-stability acidic chemical mechanical polishing solution and preparation method and application thereof Technical Field The invention relates to the technical field of polishing solutions, in particular to a high-stability acidic chemical mechanical polishing solution, and a preparation method and application thereof. Background The dielectric layer is a layer of electrically insulating material in the integrated circuit that separates the different metal layers or transistors from the metal layers. The core functions of the method comprise eliminating short circuit risks among conductive components, controlling parasitic capacitance of devices and realizing a complex three-dimensional interconnection structure. Typical materials such as SiO 2, which have dielectric constants in the range of 3.8-4.0, are prepared by CVD or the like. The key insulation isolation technology of device isolation in IC manufacture is shallow trench isolation, the core technology is that a silicon substrate is subjected to patterned etching through a silicon nitride mask to form a shallow trench, then a silicon dioxide oxidation dielectric layer is filled in the shallow trench to realize electrical isolation among elements, and then surface planarization is completed through Chemical Mechanical Polishing (CMP). The process requires a very high silicon dioxide removal rate and a very low surface defect index, which directly determine the efficiency of device isolation. Because the polishing solution of the dielectric layer prepared by the traditional silica sol spherical grinding particles is usually alkaline, the silica sol is positively charged at the moment and is difficult to combine with the dielectric layer which is positively charged on the surface of the wafer, and the friction force is weaker, so that the polishing efficiency on the silicon dioxide dielectric layer is lower. As integrated circuit technology nodes move toward smaller sizes, demands for higher polishing rates and lower polishing defects are placed on silicon dioxide dielectric layer polishing. At present, the potential of abrasive particles in the polishing solution can be effectively improved by adjusting the pH value of polishing to be acidic, and the polishing effect of the abrasive particles and the wafer is promoted, so that the polishing solution has wide application. However, in an acidic polishing solution system, silicon oxide abrasive particles are easy to agglomerate, flocculation, layering and other phenomena occur, so that the stability of the polishing solution is reduced, and the polishing effect is irrational. Therefore, there is an urgent need to develop a chemical mechanical polishing liquid having both high stability and high polishing rate, which should have high polishing rate and polishing effect while maintaining high stability. Disclosure of Invention In view of the above-mentioned shortcomings of the prior art, the present invention aims to provide a highly stable acidic chemical mechanical polishing solution, and a preparation method and application thereof, which are used for solving the problems of poor stability, low polishing rate and many surface defects of polished materials in the prior art. To achieve the above and other related objects, the present invention provides a highly stable acidic chemical mechanical polishing solution, and a preparation method and use thereof. The invention provides a high-stability acidic chemical mechanical polishing solution, which comprises, by mass, 5-30wt% of a silicon oxide abrasive, 0.01wt% to 1wt% of a modifier, 0.01wt% to 2wt% of a surfactant, 0.01wt% to 1wt% of a regulator, and the balance of a pH regulator and water, wherein the pH regulator enables the pH value of the polishing solution to be 3-5, the modifier is an organic ammonium salt and/or an organic amine, the surfactant is obtained by compounding alkyl sulfobetaine and betaine according to a mass ratio of 1:0.1-5, and the regulator is a weak acid. The mass fraction is based on the total mass of the polishing solution, and each component accounts for the percentage of the total mass of the polishing solution. The polishing solution product in the invention can be diluted according to actual needs in actual use, and can be usually diluted into Polishing is performed 2 to 10 times, for example, 2 times, 2.5 times, 3 times, 3.5 times, 4 times, 4.5 times, 5 times, 5.5 times, 6 times, 6.5 times, 7 times, 7.5 times, 8 times, 8.5 times, 9 times. In view of polishing rate, surface quality and production cost, the mass fraction of the abrasive is preferably 10wt% to 20wt%, and may be, for example, 10wt%, 12wt%, 15wt%, 18wt%, 20wt%. In view of polishing rate and surface quality, the mass fraction of the modifier is preferably 0.04wt% to 1wt%, and may be, for example, 0.04wt%, 0.05wt%, 0.08wt%, 0.1wt%, 0.2wt%, 0.4wt%, 0.5wt%, 0.8wt%, 1wt%. More preferably, the mass fraction of the modifier is 0.04-0.5 wt%. In view of polishing rate, s