SiC dummy wafer and SiC dummy wafer manufacturing method

Abstract

This invention provides a dummy wafer made of SiC fabricated by CVD that can be detected by an optical sensor, and a method for manufacturing a SiC dummy wafer. [Solution] The SiC dummy wafer 1 according to this disclosure is a SiC dummy wafer manufactured using chemical vapor deposition. The SiC dummy wafer 1 comprises a surface layer 1a that constitutes a first main surface and contains a plurality of columnar crystals of SiC, a back surface layer 1b that constitutes a second main surface opposite the first main surface and contains a plurality of columnar crystals of SiC, and an intermediate layer 1c that forms the space between the first main surface and the second main surface. The intermediate layer 1c has at least one non-permeable layer that contains a plurality of microcrystals of SiC with a particle size smaller than that of the columnar crystals of SiC in at least a portion of it.

Claims

1. A SiC dummy wafer fabricated using chemical vapor deposition, The first main surface is formed by a surface layer containing multiple columnar crystals of SiC, A second main surface opposite the first main surface is formed, and a back surface layer containing a plurality of columnar crystals of SiC is provided, The structure comprises an intermediate layer forming the space between the first main surface and the second main surface, The SiC dummy wafer has at least one non-transparent layer in which the intermediate layer contains at least a portion of a plurality of SiC microcrystals having a particle size smaller than that of the columnar SiC crystals.

2. The SiC dummy wafer according to claim 1, wherein the non-transparent layer has a thickness of about 1 / 20 or more of the thickness of the SiC dummy wafer.

3. The SiC dummy wafer according to claim 1, wherein the non-transparent layer has a thickness of approximately 5 μm or more.

4. The SiC dummy wafer according to claim 1, wherein the non-transparent layer has a transmittance of 5% or less for light in the infrared region.

5. The SiC dummy wafer according to any one of claims 1 to 4, wherein the particle size of the SiC microcrystals is approximately 0.2 μm to approximately 5 μm.

6. The SiC dummy wafer according to any one of claims 1 to 4, wherein, when the intermediate layer has two opaque layers, a layer containing a plurality of columnar crystals of SiC is provided between the two opaque layers.

7. A method for manufacturing a SiC dummy wafer using chemical vapor deposition, A process of supplying a raw material gas at a first concentration into a vacuum container and forming a first layer containing multiple columnar SiC crystals around the substrate, A step of supplying the raw material gas at a second concentration higher than the first concentration into the vacuum container, and forming a second non-permeable layer on the first layer, which contains SiC microcrystals with a particle size smaller than that of columnar SiC crystals, The process involves supplying the raw material gas at the first concentration into the vacuum container and forming a third layer containing columnar crystals of SiC on the second layer, A method for manufacturing a SiC dummy wafer, including the step of removing the aforementioned substrate.

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