Large-size silicon carbide (SiC) monocrystal growth device

Abstract

The invention belongs to the technical field of crystal growth, relates to a large-size silicon carbide (SiC) monocrystal growth device, and in particular relates to a device for the growth of a large-size SiC monocrystal by utilizing a physical vapor transportation method (PVT). The device is particularly provided with a crucible structure for growing the SiC monocrystal by utilizing the PVT technology, wherein a spherical hole is formed on the upper surface of a crucible cover; a thermal insulation material in a special shape, which can be used for completely bonding the whole hole, is put into the hole to be flattened; and then a graphite cover slice is put into the hole and is flattened forcibly in a pressing manner. Therefore, a sandwich thermal insulation layer is formed in the crucible cover, i.e., the integrated heat dissipation of the surface of the crucible cover to the outside is uniform. As a result, the radial thermal gradient of the crystal growth is decreased.

Description

technical field [0001] The invention belongs to the technical field of crystal growth, and relates to a device for growing large-size SiC single crystals by physical vapor transport (PVT). The device specifically relates to a crucible structure for growing silicon carbide single crystals using PVT technology. Background technique [0002] As a representative of the third-generation semiconductor single crystal material, SiC crystal has high hardness (second only to diamond), high thermal conductivity (4.9W / cm K), and low thermal expansion coefficient compared with many other semiconductor single crystal materials. (3.1-4.5×10-6 / K), large band gap (2.40-3.26eV), high saturation drift velocity (2.0-2.5×107cm / s), strong critical breakdown field (2~3×106V / cm ), high chemical stability, strong radiation resistance and other excellent properties. These excellent properties make SiC crystals have broad application prospects in high temperature, high pressure, and strong radiation...

AI Technical Summary

Problems solved by technology

It is also unavoidable that the radial temperature gradient of the entire crucible cover and the inside of the crucible is too large due to the skin effect (concentrated heat generation) of the eddy current on the graphite crucible wall and the heat dissipation effect of the upper temperature measuring hole opening of the insulation barrel, which directly leads to The radial temperature gradient of the crystal is too large

The problem of excessive radial temperature gradient is particularly prominent when growing large-sized single crystals. Therefore, excessive thermal stress during crystal growth may easily produce micropipes, stacking fault grain boundaries, and other defects. Large, the crystal is easy to crack in the post-processing process, and the yield is low

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