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CN-122012021-A - Cerium oxide composite abrasive particle with heterogeneous core-shell structure, and preparation method and application thereof

CN122012021ACN 122012021 ACN122012021 ACN 122012021ACN-122012021-A

Abstract

The invention belongs to the field of polishing materials, and relates to cerium oxide composite abrasive particles with heterogeneous core-shell structures, a preparation method and application thereof. Wherein, the cerium oxide composite abrasive particles with heterogeneous core-shell structures comprise an inner core formed by mesoporous carbon nanospheres and a cladding shell formed by cerium oxide nanoparticles. The inner core of the cerium oxide composite abrasive particle has lower elastic modulus and rich pore structure, and can generate elastic buffering in the polishing process, so that the scratches on the surface of a wafer and the damage on the subsurface are reduced. The shell layer has high specific surface area and excellent chemical reactivity, and can improve the material removal rate. Compared with a single cerium oxide abrasive, the core-shell structure of the invention effectively inhibits cerium oxide particle agglomeration, remarkably improves the dispersion stability of the polishing solution, and simultaneously realizes the cooperative optimization of the material removal rate and the surface roughness.

Inventors

  • ZHANG FAN
  • YUAN WEI
  • YANG FENGJIA

Assignees

  • 复旦大学

Dates

Publication Date
20260512
Application Date
20251230

Claims (10)

  1. 1. The cerium oxide composite abrasive particle with the heterogeneous core-shell structure is characterized by comprising an inner core formed by mesoporous carbon nanospheres and a cladding shell formed by cerium oxide nanoparticles.
  2. 2. The ceria composite abrasive particle of claim 1 wherein the inner core is made from mesoporous carbon nanospheres surface modified with nitric acid.
  3. 3. The ceria composite abrasive particle of claim 1 wherein the diameter of the inner core is 100-200nm and the thickness of the cladding shell is 10-50nm.
  4. 4. The ceria composite abrasive particle of claim 1 wherein the diameter of the inner core is 100-160nm and the thickness of the cladding shell is 10-25nm.
  5. 5. A method of making the ceria composite abrasive particles of any one of claims 1 to 4 comprising the steps of: S1, preparing a mesoporous carbon nanosphere precursor by a block copolymer soft template method; s2, carrying out surface modification treatment on the mesoporous carbon nanosphere precursor by nitric acid to obtain a modified mesoporous carbon nanosphere precursor; S3, coating cerium oxide nano particles on the surface of the modified mesoporous carbon nano sphere precursor by an in-situ chemical precipitation method to obtain a cerium oxide composite abrasive particle precursor; And S4, carrying out post-treatment on the cerium oxide composite abrasive particle precursor to obtain the cerium oxide composite abrasive particle.
  6. 6. The preparation method of the mesoporous carbon nanosphere according to claim 5, wherein the step S1 comprises the steps of carrying out a synergistic self-assembly reaction of a carbon source, a block copolymer template agent, a regulator and alkali at room temperature to obtain a mesoporous carbon nanosphere precursor; Wherein the carbon source is dopamine, the block copolymer template agent is polyethylene oxide-polypropylene oxide-polyethylene oxide triblock polymer, the regulator is alkylbenzene, and the reaction time is 20-40h; the mass ratio of the regulator to the block copolymer template agent is (0.5-2): 1, and the mass ratio of the carbon source to the regulator is 1:2-1:3.
  7. 7. The method according to claim 5, wherein step S2 comprises the steps of: Dispersing the mesoporous carbon nanosphere precursor into water, adding nitric acid, performing ultrasonic treatment for 20-30min, and centrifuging and washing to obtain a modified mesoporous carbon nanosphere precursor; Wherein the concentration of the nitric acid is 0.1-1mol/L.
  8. 8. The method according to claim 5, wherein step S3 comprises the steps of: Adding a modified mesoporous carbon nanosphere precursor, hexamethylenetetramine and a cerium source into deionized water, uniformly stirring, and reacting a mixed system under the condition of heating and stirring to obtain a cerium oxide composite abrasive particle precursor, wherein the cerium source is soluble cerium salt and a hydrate thereof; Wherein, the mass ratio of the hexamethylenetetramine to the precursor of the modified mesoporous carbon nanospheres is 0.5:1-2:1, after each component is added into deionized water, the concentration of the hexamethylenetetramine is 1.5-2g/L, the concentration of cerium salt is 4-6g/L, the stirring time is 1-2h, the heating temperature is 80-100 ℃, and the reaction time is 2-5h.
  9. 9. The method according to claim 5, wherein step S4 comprises the steps of: Performing first-stage calcination treatment on the cerium oxide composite abrasive particle precursor in a protective atmosphere, and then performing second-stage calcination treatment in an air atmosphere to obtain cerium oxide composite abrasive particles; wherein the calcination temperature of the first stage calcination treatment is 200-400 ℃, the calcination time is 2-4h, the calcination temperature of the second stage calcination treatment is 700-900 ℃, and the calcination time is 1-3h.
  10. 10. Use of the ceria composite abrasive particles according to any one of claims 1 to 4 or the ceria composite abrasive particles prepared by the preparation method according to any one of claims 5 to 9, wherein the ceria composite abrasive particles are used in a polishing liquid.

Description

Cerium oxide composite abrasive particle with heterogeneous core-shell structure, and preparation method and application thereof Technical Field The invention relates to the technical field of polishing materials, in particular to cerium oxide composite abrasive particles with heterogeneous core-shell structures, a preparation method and application thereof. Background Since the invention of Integrated Circuits (ICs), the semiconductor industry has undergone several technological innovations, which continuously push electronic products to develop toward miniaturization, high performance and low power consumption, and in the chip manufacturing process, the requirements on the planarization process are increasingly increased, and the quality of the planarization process directly affects the performance and yield of the chip. Chemical Mechanical Polishing (CMP) is a planarization technique that is widely used in integrated circuit fabrication to planarize a material surface by combining chemical etching with mechanical polishing, using the combined action of abrasive particles and chemical agents in an abrasive suspension. Abrasive particles, i.e., abrasive particles, are a core component of the chemical mechanical polishing process, whose properties directly affect the polishing effect and surface quality. Polishing abrasives can be classified into various types according to their materials and characteristics, including alumina abrasives, silica abrasives, cerium oxide abrasives, and the like. Among them, cerium oxide abrasives are widely favored for their high chemical reactivity and excellent mechanical properties. However, the existing single cerium oxide abrasive still has the defects of low material removal rate, irregular shape, easy agglomeration, high viscosity, low selectivity and the like. The higher hardness of the single cerium oxide leads to the easy rigid contact with the surface of the wafer in the polishing process, thereby generating scratches, microcracks and subsurface damage, resulting in the increase of the surface roughness after polishing, and being difficult to meet the dual requirements of high removal efficiency and high surface quality. Accordingly, there is a need to provide an abrasive that is capable of effectively suppressing agglomeration, reducing the risk of surface scratches of a product, and significantly improving the surface roughness of the product while increasing the material removal rate. Disclosure of Invention First, the technical problem to be solved The invention provides a cerium oxide composite abrasive particle with a heterogeneous core-shell structure, a preparation method and application thereof, and aims to solve the problems that in the prior art, a single cerium oxide abrasive material is low in material removal rate and easy to agglomerate, and surface scratches of a polished wafer are increased and roughness is increased due to high hardness, so that the material removal rate is difficult to be improved and the surface quality is difficult to be guaranteed. (II) technical scheme In order to achieve the above purpose, the main technical scheme adopted by the invention comprises the following steps: In a first aspect, the present invention provides a ceria composite abrasive particle having a heterogeneous core-shell structure, comprising an inner core of mesoporous carbon nanospheres, and a cladding shell of ceria nanoparticles. The cerium oxide composite abrasive particle as described above is preferably prepared by surface-modifying mesoporous carbon nanospheres with nitric acid. The ceria composite abrasive particles as described above, preferably, the diameter of the inner core is 100 to 200nm, and the thickness of the coating shell is 10 to 50nm. The ceria composite abrasive particles as described above, preferably, the diameter of the inner core is 100 to 160nm, and the thickness of the coating shell is 10 to 25nm. In a second aspect, the present invention provides a method for preparing the above cerium oxide composite abrasive particles, comprising the steps of: S1, preparing a mesoporous carbon nanosphere precursor by a block copolymer soft template method; s2, carrying out surface modification treatment on the mesoporous carbon nanosphere precursor by nitric acid to obtain a modified mesoporous carbon nanosphere precursor; S3, coating cerium oxide nano particles on the surface of the modified mesoporous carbon nano sphere precursor by an in-situ chemical precipitation method to obtain a cerium oxide composite abrasive particle precursor; And S4, carrying out post-treatment on the cerium oxide composite abrasive particle precursor to obtain the cerium oxide composite abrasive particle. The preparation method comprises the following steps that a carbon source, a block copolymer template agent, a regulator and alkali are subjected to cooperative self-assembly reaction at room temperature to obtain a mesoporous carbon nanosphere precursor; Wherein