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CN-110735183-B - Susceptor, apparatus and method for producing SiC single crystal

CN110735183BCN 110735183 BCN110735183 BCN 110735183BCN-110735183-B

Abstract

The present invention relates to a susceptor for supporting a seed crystal for single crystal growth of SiC, and an apparatus and a method for producing a SiC single crystal including the susceptor. The purpose of the present invention is to provide a susceptor which can remove gas generated from a heated binder in a state where a seed crystal is fixed with the binder. The susceptor (103) of the present invention is a susceptor (103) for a seed crystal (102) for crystal growth, wherein one main surface (103 a) of the seed crystal (102) is flat, and has a gas permeation region (106), and the gas permeation region (106) is formed such that the thickness from the one main surface (103 a) is locally reduced.

Inventors

  • NOGUCHI SHUNSUKE

Assignees

  • 昭和电工株式会社

Dates

Publication Date
20260512
Application Date
20190712
Priority Date
20180718

Claims (8)

  1. 1. A susceptor for a seed crystal for crystal growth, the seed crystal being bonded to one main surface of the susceptor by an adhesive layer comprising an adhesive, The main surface of the side to which the seed crystal is bonded is flat, The susceptor has a gas permeation region formed so that the thickness from the one main surface is locally reduced, The thickness of the gas permeation area is more than 1mm and less than 5mm, The thickness of the gas permeable region increases as it moves away from the center.
  2. 2. The base of claim 1, wherein the base is configured to receive the base, The region other than the gas permeation region includes a portion having a thickness of 10mm or more.
  3. 3. The base of claim 1, wherein the base is configured to receive the base, When the distance from the center to the outer periphery is r in a plan view as viewed in the thickness direction, the gas permeation area is included in a range of a distance (r/2) from the center.
  4. 4. A susceptor for a seed crystal for crystal growth, the seed crystal being bonded to one main surface of the susceptor by an adhesive layer comprising an adhesive, The main surface of the side to which the seed crystal is bonded is flat, The susceptor has a gas permeation region, wherein the gas permeation region is a region extending in the depth direction in a part of the one main surface, and a space communicating with the outside is provided inside the gas permeation region.
  5. 5. The base of claim 4, wherein the base is configured to receive the base, The void is formed at a distance of 1mm or more and 5mm or less from the one main surface.
  6. 6. A device for producing SiC single crystals, characterized in that, The susceptor of any one of claims 1 to 5.
  7. 7. A method for producing a SiC single crystal by using the susceptor according to any one of claims 1 to 5, After the seed crystal is attached to the main surface of the base on one side by using an adhesive, the seed crystal is pressed against the base side in a heating step for curing the adhesive.
  8. 8. The method for producing a SiC single crystal according to claim 7, After the heating step, a step of filling the concave portion formed in the susceptor is provided.

Description

Susceptor, apparatus and method for producing SiC single crystal Technical Field The present invention relates to a susceptor for supporting a seed crystal (seed crystal) for growing a SiC single crystal, and an apparatus and a method for producing a SiC single crystal including the susceptor. The present application claims priority based on patent application 2018-135092, filed in japan, 7-18, the contents of which are incorporated herein by reference. Background Silicon carbide (SiC) as a semiconductor material is known to have a wider band gap than Si (silicon) which is widely used as a device substrate at present, and to be excellent in pressure resistance and thermal conductivity. Therefore, silicon carbide is expected to be applied to power devices, high-frequency devices, high-temperature working devices, and the like. A semiconductor device using silicon carbide uses a SiC epitaxial wafer in which an epitaxial film is formed on a SiC wafer. An epitaxial film provided on a SiC wafer by a chemical vapor deposition method (Chemical Vapor Deposition: CVD) becomes an active region of a SiC semiconductor device. The active region of the epitaxial film inherits and/or converts the crystal defects of the SiC wafer as they are to other crystal defects, thereby being affected by the quality of the SiC wafer. Therefore, a high quality SiC wafer free from defects is demanded. SiC wafers are produced by slicing an ingot of SiC single crystal. SiC single crystals can be generally produced by sublimation. The sublimation method is a method in which a seed crystal (seed crystal) composed of a SiC single crystal is placed on a susceptor placed in a crucible made of graphite, and the crucible is heated to thereby supply sublimation gas sublimated from a raw material powder in the crucible to the seed crystal, so that the seed crystal grows to a larger SiC single crystal. During the growth of SiC single crystal, the seed crystal is fixed to the susceptor with a binder. As the binder, a carbon binder containing an organic solvent is often used (patent document 1). Prior art literature Patent document 1 Japanese patent application laid-open No. 2015-193494 Disclosure of Invention During the curing of the binder, gas is generated from the heated carbon binder. If a void is formed between the susceptor and the seed crystal due to the gas, a macroscopic defect (penetration defect) extends therefrom to reach the growing SiC single crystal. Therefore, the adhesion between the growing SiC single crystal and the seed crystal and the susceptor may be reduced and the grown SiC single crystal and the seed crystal may be peeled off. Even without exfoliation, the grown SiC single crystal contains macroscopic defects and is degraded. If a small-diameter seed crystal is used, the pressurizing and/or vacuum pressurizing and defoamation treatment is performed by applying a load to the seed crystal before growing the SiC single crystal, whereby the gas can be released outward from the side not covered with the seed crystal. However, due to the recent demand, in the case of manufacturing a large-diameter SiC wafer, a large-diameter seed crystal is used correspondingly to the seed crystal, and in this case, gas generated near the center of the adhesive layer is difficult to release from the side portions. The present invention has been made in view of such a situation, and an object thereof is to provide a susceptor capable of removing gas generated from a heated binder in a state where a seed crystal is fixed with the binder. (1) In one aspect of the present invention, the susceptor is a susceptor for a seed crystal for crystal growth, and a main surface of the susceptor on which the seed crystal is bonded is flat, and the susceptor has a gas permeation region formed such that a thickness of the susceptor from the main surface on the side becomes locally thinner. (2) The susceptor according to (1) above, wherein the thickness of the gas permeation area is preferably 1mm or more and less than 5mm. (3) The susceptor according to any one of (1) and (2), wherein the thickness of the gas permeation region preferably increases as it goes away from the center. (4) The susceptor according to any one of (1) to (3), wherein the region other than the gas permeation region preferably includes a portion having a thickness of 10mm or more. (5) The susceptor according to any one of (1) to (4), wherein the gas permeation region is preferably included in a range of a distance (r/2) from the center when the distance from the center to the outer periphery is r in a plan view in the thickness direction. (6) In another aspect of the present invention, the susceptor is a susceptor for a crystal growth seed crystal, wherein a main surface of the susceptor on which the seed crystal is bonded is flat, and the susceptor has a gas permeation region in which a part of the main surface on the side spreads in a depth direction, and a space communicating with the outs