Method for preparing silicon carbide single crystal

Abstract

The invention discloses a method for preparing silicon carbide single crystals, and belongs to the technical field of semiconductor material preparation. The method for preparing the silicon carbide single crystal comprises the following steps: S1, growing an aluminum nitride substrate by a PVT method, and attaching the aluminum nitride substrate to a graphite crucible cover; and S2, taking the graphite crucible cover obtained in the step S1 and the pretreated graphite crucible body as reaction containers, and growing the silicon carbide single crystal by a PVT method. Compared with monocrystalline silicon serving as a substrate, aluminum nitride is adopted as the substrate, lattice mismatch and thermal expansion coefficient mismatch between the substrate and silicon carbide are reduced, and therefore silicon carbide single crystals with lower defect density can grow.

Description

technical field [0001] The invention belongs to the technical field of semiconductor material preparation, and in particular relates to a method for preparing a silicon carbide single crystal. Background technique [0002] At present, the preparation methods of silicon carbide single crystal mainly include: physical vapor transport method (Physical VaporTransport, PVT); top seed solution growth method (Top Seed Solution Growth method, TSSG); high temperature chemical vapor deposition method (High Temperature Chemical Vapor Deposition, HT-CVD). Among them, the crystal size grown by the TSSG method is small and is currently only used for laboratory growth. The commercialized technical routes are mainly PVT and HT-CVD. Compared with the HT-CVD method, the SiC single crystal grown by the PVT method requires simple equipment. The operation is easy to control, and the equipment price and operating cost are low. [0003] The growth of silicon carbide single crystal by PVT method ...

AI Technical Summary

Problems solved by technology

[0004] At present, silicon carbide crystals are grown by PVT method, usually based on single crystal silicon, but due to the large lattice mismatch and thermal mismatch between silicon carbide and silicon, there will be a large number of misfit dislocations in the growth of silicon carbide on silicon , stacking dislocations, line defects, twins, etc., affect the crystal quality of silicon carbide

Images