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CN-121992398-A - Graphite rod ceramic coating for semiconductor wafer epitaxial support and laser cladding preparation method thereof

CN121992398ACN 121992398 ACN121992398 ACN 121992398ACN-121992398-A

Abstract

The invention belongs to the technical field of laser cladding, and provides a graphite rod ceramic coating for semiconductor wafer epitaxial support and a laser cladding preparation method thereof, which are used for solving the problems of low bonding strength, low density and the like of a ceramic layer on the surface of an existing graphite substrate. The invention discloses a graphite rod ceramic coating for supporting a semiconductor wafer epitaxy, which comprises a graphite substrate, wherein a transition layer, a ceramic intermediate layer and a ceramic functional surface layer are sequentially arranged on the outer side of the graphite substrate. The invention can improve the bonding strength between the ceramic coating and the graphite rod matrix, effectively solve the problems of pores, cracks and the like of the ceramic coating, finally improve the compactness of the ceramic coating, improve the high insulation, high wear resistance and high cleanliness of the ceramic coating, and is suitable for manufacturing high-end semiconductors.

Inventors

  • DU ZHIHUA
  • LI ZUOYU
  • SUN ZE
  • YANG YI
  • QI HUAN
  • CAI GUOSHUANG

Assignees

  • 成都青石激光科技有限公司

Dates

Publication Date
20260508
Application Date
20260330

Claims (10)

  1. 1. The graphite rod ceramic coating for the semiconductor wafer epitaxial support is characterized by comprising a graphite substrate, wherein a transition layer, a ceramic intermediate layer and a ceramic functional surface layer are sequentially arranged on the outer side of the graphite substrate.
  2. 2. The graphite rod ceramic coating for epitaxial support of a semiconductor wafer according to claim 1, wherein the transition layer is formed by cladding Ti powder on a graphite substrate by laser cladding, and the thickness of the transition layer is 200-500 μm.
  3. 3. The graphite rod ceramic coating for epitaxial support of a semiconductor wafer according to claim 1, wherein the ceramic intermediate layer is formed by cladding intermediate powder on a transition layer in a laser cladding mode, the intermediate powder is composed of yttrium oxide powder and aluminum oxide powder, the mass fraction of the yttrium oxide powder is 0.5-0.9%, and the thickness of the ceramic intermediate layer is 50-100 μm.
  4. 4. The graphite rod ceramic coating for epitaxial support of the semiconductor wafer according to claim 1, wherein the ceramic functional surface layer is formed by cladding functional powder on a ceramic intermediate layer in a laser cladding mode, the functional powder is composed of yttrium oxide powder and aluminum oxide powder, the mass fraction of the yttrium oxide powder is 1.7-2.5%, and the thickness of the ceramic functional surface layer is 300-900 μm.
  5. 5. A method of preparing a graphite rod ceramic coating for epitaxial support of a semiconductor wafer according to any one of claims 1 to 4, comprising: (1) Pretreating a graphite matrix; (2) Preheating the graphite substrate by utilizing laser homologous heating and medium-frequency induction heating, and heating the region to be clad of the graphite substrate to 800-1000 ℃; (3) Cladding the transition layer, namely cladding Ti powder on the surface of the preheated graphite substrate by adopting a coaxial powder feeding mode to form a transition layer with the thickness of 200-500 mu m; (4) Cladding the ceramic intermediate layer, namely cladding intermediate powder on the Ti transition layer by adopting a coaxial powder feeding mode to form the ceramic intermediate layer; (5) Cladding ceramic functional surface layer, namely cladding functional powder on the ceramic intermediate layer by adopting a coaxial powder feeding mode to form the ceramic functional surface layer; (6) And cooling in a step cooling mode after the ceramic functional surface layer is completed, so as to complete the preparation of the graphite matrix ceramic coating.
  6. 6. The method for producing a graphite rod ceramic coating for epitaxial support of a semiconductor wafer according to claim 5, wherein in the step (4), the intermediate powder is composed of yttrium oxide powder and aluminum oxide powder, the mass fraction of the yttrium oxide powder is 0.5 to 0.9%, the purity of the aluminum oxide powder is not less than 99.99%, the grain size is 30 to 100 μm, and the thickness of the ceramic intermediate layer composed of the intermediate powder is 50 to 100 μm.
  7. 7. The method for preparing the graphite rod ceramic coating for semiconductor wafer epitaxial support according to claim 6, wherein the laser power is 1500-2000W, the scanning speed is 300-600mm/min and the powder feeding speed is 10-22g/min when the laser cladding is carried out in the step (4).
  8. 8. The method for preparing a graphite rod ceramic coating for epitaxial support of a semiconductor wafer according to claim 5, wherein in the step (5), the functional powder is composed of yttrium oxide powder and aluminum oxide powder, the mass fraction of the yttrium oxide powder is 1.7-2.5%, the purity of the aluminum oxide powder is not less than 99.99%, the granularity is 30-100 μm, and the thickness of the ceramic functional surface layer composed of the functional powder is 300-900 μm.
  9. 9. The method for preparing the graphite rod ceramic coating for semiconductor wafer epitaxial support according to claim 8, wherein the laser power is 1600-2500W, the scanning speed is 300-800mm/min, and the powder feeding speed is 11-28g/min when the laser cladding is carried out in the step (5).
  10. 10. The method for preparing a graphite rod ceramic coating for epitaxial support of a semiconductor wafer according to claim 5, wherein the step cooling is performed in the step (6) and the graphite rod ceramic coating is cooled to room temperature at a rate of 5-10 ℃ per minute under the protection of argon with a purity of not less than 99.999% and a flow rate of 5-15L/min.

Description

Graphite rod ceramic coating for semiconductor wafer epitaxial support and laser cladding preparation method thereof Technical Field The invention belongs to the technical field of laser cladding, and particularly relates to a graphite rod ceramic coating for semiconductor wafer epitaxial support and a laser cladding preparation method thereof. Background The epitaxial support of the semiconductor wafer needs to use a graphite rod, and the surface of the graphite rod (graphite matrix) needs to be provided with a ceramic layer. In the semiconductor field, the main purposes of providing a ceramic layer are as follows: Graphite itself is a conductive material that can release trace amounts of ash or impurity atoms (e.g., metal ions) at high temperatures (e.g., during CVD, MOCVD, epitaxial growth, single crystal silicon growth furnaces, etc.), which may contaminate semiconductor materials (e.g., silicon, gaN, etc.). The ceramic layer (such as silicon carbide SiC, boron nitride BN, aluminum oxide Al 2O3 and the like) has high chemical inertness, can effectively block the graphite matrix from being in direct contact with the process atmosphere, and prevents impurities from migrating into the wafer or the reaction cavity. Oxidation resistance and corrosion resistance graphite is easily oxidized in high-temperature oxygen-containing environment, which causes component loss, generates particles and affects process stability. The ceramic layer may provide a dense physical barrier that significantly increases the useful life of the graphite component in oxidizing or corrosive atmospheres (e.g., O 2、Cl2, HCl, etc.). The ceramic coating is generally smoother and denser in surface, can reduce particle adhesion, is easy to clean (such as removing surface deposits by wet or dry etching), thereby prolonging the maintenance period of the graphite component and reducing the production cost. The electrical and thermal properties are controlled, that is, the partial ceramic coating has specific resistivity or thermal conductivity, and can be used for adjusting the electrothermal characteristics of the graphite heater, the electrode or the support piece so as to meet the uniformity requirement of a special process. Mechanical protection the coating may enhance the hardness and wear resistance of the graphite surface and reduce mechanical damage during loading/unloading wafer or component contact. However, the following technical problems exist in providing an alumina ceramic layer on a graphite substrate (graphite rod): 1. The thermal expansion coefficients of the graphite matrix and the alumina ceramic are extremely different, and the direct laser cladding is easy to crack and peel due to the concentration of residual stress, so that the coating is easy to generate gaps and penetrating cracks, and the bonding strength is insufficient and the compactness is low. 2. The traditional coating process has large thermal stress, poor interface bonding and difficult achievement of high-temperature stability and insulating property. 3. The existing surface strengthening technology (plasma spraying, vapor deposition, laser cladding and the like) has the following obvious defects: (1) The bonding strength is low, most of the bonding is mechanical bonding and non-metallurgical bonding, and the bonding is easy to fail at high temperature; (2) The coating has poor uniformity, high porosity and insufficient high temperature resistance and insulation performance; (3) The graphite matrix is easy to overheat and damage, and the cracking rate of the coating is high; (4) The multiple requirements of high bonding strength, thick coating, high temperature resistance and high density cannot be met. Disclosure of Invention The invention aims to solve the problems of low bonding strength, low density and the like of the ceramic layer on the surface of the existing graphite substrate, provides the graphite rod ceramic coating for the epitaxial support of the semiconductor wafer and the laser cladding preparation method thereof, can improve the bonding strength between the ceramic layer and the graphite rod substrate, effectively solve the problems of pores, cracks and the like of the ceramic layer, finally improve the density of the ceramic layer, improve the high insulation, high wear resistance and high cleanliness of the ceramic layer, and is suitable for manufacturing high-end semiconductors. In order to solve the technical problems, the invention adopts the following technical scheme: a laser cladding preparation method of a graphite rod ceramic coating for semiconductor wafer epitaxial support comprises the following steps: (1) And (5) pretreatment of a graphite matrix. (2) And (3) preheating the graphite matrix, namely preheating the graphite matrix by utilizing laser homologous heating and medium-frequency induction heating, and heating the region to be clad of the graphite matrix to 800-1000 ℃. (3) Cladding the transition layer, namely cladding