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CN-121973092-A - Ordered microscopic consolidated abrasive polishing pad for lithography and preparation method thereof

CN121973092ACN 121973092 ACN121973092 ACN 121973092ACN-121973092-A

Abstract

The invention relates to a photoetching ordered microcosmic fixed abrasive polishing pad and a preparation method thereof. Compared with the prior art, the polishing pad disclosed by the invention has the advantages that the micro-polishing columns are orderly distributed and formed on the abrasive base according to a preset distribution arrangement mode, the distribution shape and the direction position of the micro-polishing columns on the abrasive base are kept unchanged, the regular distribution and the uniform distribution can be realized, the distribution and the size of the micro-polishing columns can be adjusted according to the photoetching pattern to meet different polishing requirements, and then the filling body is compositely filled between the micro-polishing columns of the substrate to keep the stability of the micro-polishing columns.

Inventors

  • ZHANG LIJUAN

Assignees

  • 上海芯谦集成电路有限公司

Dates

Publication Date
20260505
Application Date
20260407

Claims (10)

  1. 1. The photoetching ordered micro fixed abrasive polishing pad is characterized by comprising a substrate and a filler, wherein the substrate is a silicon dioxide substrate, a cerium dioxide substrate or an aluminum oxide substrate, the substrate comprises an abrasive base and a plurality of micro grinding columns, the micro grinding columns are fixedly formed on the abrasive base through photoetching a surface to be subjected to photoetching of the substrate, the micro grinding columns are orderly distributed on the abrasive base according to a photoetching pattern, so that the micro grinding columns are orderly distributed on a micro level, the size of the micro grinding columns is controllable, the passivation of fixed abrasive is prevented, the chemical stability requirements of a process below 5nm on surface defects and materials of polished products are met, the filler is polyurethane, and the filler is compositely filled among the micro grinding columns on the abrasive base.
  2. 2. The lithographically ordered micro-bonded abrasive polishing pad of claim 1, wherein the micro-abrasive pillars are micro-scale and/or nano-scale in size.
  3. 3. The lithographically ordered micro-bonded abrasive polishing pad of claim 2, wherein the micro-abrasive pillars are circular pillars with a lithographic diameter of 0.01um to 500um, and/or polygonal pillars with a lithographic side length of 0.01um to 500 um.
  4. 4. The lithographically ordered micro-bonded abrasive polishing pad of claim 1, wherein the filler is formed by casting polyurethane pre-polymer between micro-abrasive pillars on an abrasive base and sulfidizing to maintain the strength of the micro-scale abrasive pillars.
  5. 5. The lithographically ordered micro-bonded abrasive polishing pad of claim 4, wherein the polyurethane prepolymer is vacuum cast and maintained in a vacuum state for 1 min-30 min.
  6. 6. The lithographically ordered micro-bonded abrasive polishing pad of any one of claims 1-5, wherein the substrate has a diameter of 2 mm-830 mm and a thickness of 1 mm-3 mm.
  7. 7. A preparation method of the photoetching ordered micro-concreted abrasive polishing pad is characterized by comprising the steps of coating photoresist on a surface to be photoetched of a substrate, photoetching the substrate coated with the photoresist according to a photoetching pattern to divide the substrate into an abrasive base and a plurality of micro-grinding columns, orderly distributing the micro-grinding columns to form the abrasive base, removing the photoresist from the photoetched substrate, and filling filler composites between the micro-grinding columns on the abrasive base to form the photoetching ordered micro-concreted abrasive polishing pad.
  8. 8. The method for preparing the photoetching ordered micro-consolidated abrasive polishing pad according to claim 7, wherein the step of compositely filling the filler between micro-grinding columns on the abrasive base comprises the steps of selecting polyurethane prepolymer and vulcanizing agent to cast a photoresist-removed substrate, and vulcanizing the cast substrate at 80-200 ℃ for 1-36 h; wherein the isocyanate group content of the polyurethane prepolymer is 3% -12%, the vulcanizing agent is diamine cross-linking agent, and the casting condition is that the polyurethane prepolymer is subjected to negative pressure casting in a vacuum casting mold, and the negative pressure state is maintained for 1 min-30 min.
  9. 9. The method for preparing the photoetching ordered microscopic fixed abrasive polishing pad according to claim 7, wherein the photoresist is coated on the surface to be photoetched of the substrate, comprises the steps of pre-cleaning the substrate by a cleaning solvent to remove surface impurities, drying the cleaned substrate, putting the dried substrate into an ultraviolet lamp with the wavelength of 230-390 nm for irradiation for 1-60 min, diluting the positive or negative photoresist to 1-80% concentration, coating the photoresist on the substrate, and drying the substrate coated with the photoresist at the temperature of 20-200 ℃ for 1-60 min; The cleaning solvent comprises one or more of water, alcohol solvents, ketone solvents, amide solvents, ether solvents and benzene solvents, and the photoresist is coated by one or more of spin coating, spraying, atomizing, roll coating and dipping.
  10. 10. The method for preparing the photoetching ordered microscopic fixed abrasive polishing pad according to claim 7, which is characterized in that photoetching is carried out on a substrate coated with photoresist according to a photoetching pattern, the method comprises the steps of placing the substrate coated with photoresist on a photoetching machine stage, photoetching the substrate coated with photoresist according to a photoetching pattern mask by selecting photoetching wavelengths of 200-490 nm, placing the substrate subjected to photoetching in a developing solution for 5-120 s, drying the substrate subjected to development at 70-200 ℃ for 30-300 min, and etching the substrate subjected to development and drying by dry plasma according to the photoetching pattern to form microscopic grinding columns, wherein the developing solution is sodium hydroxide with the concentration of 0.1-40%; Removing the photoresist from the photoetching substrate, namely placing the etched substrate into a photoresist removing reagent to remove the photoresist, and drying the photoresist-removed substrate at the temperature of 70-150 ℃ for 5-60 min.

Description

Ordered microscopic consolidated abrasive polishing pad for lithography and preparation method thereof Technical Field The invention relates to the technical field of wafer grinding and polishing in semiconductors, in particular to a photoetching ordered microcosmic fixed abrasive polishing pad and a preparation method thereof. Background In the fields of semiconductors, optical elements, and precision machining, surface planarization techniques are a key element in determining device performance. Chemical Mechanical Polishing (CMP) has been the mainstream process for achieving wafer planarization in the semiconductor field for the past decades, and its core consumables mainly include polishing pads and polishing slurries. Wherein the polishing pad is used as a carrier for chemically etching the polishing slurry and is also used as a core material for physical removal. In recent years, as integrated circuit fabrication nodes go below 3nm, there is an increasing demand for defect control on the wafer surface. Conventional polishing techniques gradually fail due to thermal damage and material residue problems. Meanwhile, in the process below 5nm, new materials such as ruthenium, molybdenum and the like also put higher demands on the chemical stability of the polishing pad. The traditional polishing pad is prepared by mixing polyurethane prepolymer and abrasive particles and then solidifying, but the shape and the direction of the abrasive particles are irregularly distributed in microscopic view, even the abrasive particles are agglomerated, the polishing pad is easy to scratch polished products such as wafers and the like during polishing, and the polishing pad has poor chemical stability during polishing, so that the polishing effect of the polishing pad on the polished products is poor, and the quality of the polished products is influenced. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a photoetching ordered microcosmic fixed abrasive polishing pad and a preparation method thereof. The aim of the invention can be achieved by the following technical scheme: the invention provides a photoetching ordered microcosmic fixed abrasive polishing pad, which comprises a substrate and a filler, wherein the substrate is a silicon dioxide substrate, a cerium dioxide substrate or an aluminum oxide substrate, the substrate comprises an abrasive base and a plurality of microcosmic grinding columns, the microcosmic grinding columns are fixedly formed on the abrasive base through photoetching a surface to be subjected to photoetching of the substrate, the microcosmic grinding columns are orderly distributed on the abrasive base according to a photoetching pattern, so that the microcosmic grinding columns are orderly distributed on a microcosmic layer, the size of the microcosmic grinding columns is controllable, the passivation of fixed abrasive is prevented, the surface defect of a polished product and the chemical stability requirement of materials in a process below 5nm are met, the filler is polyurethane, and the filler is compositely filled between the microcosmic grinding columns on the abrasive base. Compared with the prior art, the substrate of the invention adopts pure abrasive substrates such as a silicon dioxide substrate, a cerium oxide substrate or an aluminum oxide substrate, and the like, the surface of the substrate to be polished is photoetched according to a photoetching pattern, a plurality of micro grinding columns are orderly distributed and formed on an abrasive base according to a preset distribution arrangement mode on a micro level, the micro grinding columns replace traditional grinding particles on the micro level, the distribution shape and the direction position of the micro grinding columns on the abrasive base are kept unchanged, the regular distribution and the uniform distribution can be presented, the distribution and the size of the micro grinding columns can be adjusted according to the photoetching pattern to meet different polishing requirements, and then the polyurethane filling body is compositely filled between the micro grinding columns of the substrate to keep the stability of the micro grinding columns, so that the polishing pad of the invention can be suitable for the micro level, the method has the advantages that the requirements of processes below 5nm are met, namely, traditional grinding particles are replaced by forming microscopic grinding columns through photoetching, and the plurality of grinding columns are orderly distributed and controllable in particle size on the microscopic level, so that the problems of agglomeration and random distribution in the polishing application process of the traditional grinding abrasive are solved, the passivation problem of the fixed abrasive polishing pad in the use process is also solved well, the requirements of processes below 5nm on the surface defects of polishing products and the