A kind of growth method of high-quality aluminum nitride single crystal

Abstract

The invention discloses a method for growing a high-quality aluminum nitride single crystal. In the method, the initial deposition layer adopts a large aluminum nitride / silicon carbide mixed filler mode, and then high-purity aluminum nitride powder is used, and the temperature changes during the growth process. The aluminum nitride filler layer in the crucible is from bottom to top. The first layer is the aluminum nitride powder layer, the second layer is the sintered aluminum nitride particle layer, and the third layer is the particle mixture of aluminum nitride and silicon carbide. material, and the fourth layer is a source of particle mixture of aluminum nitride and silicon carbide. In the present invention, by doping silicon carbide powder in aluminum nitride powder, different silicon carbide: aluminum nitride ratios are used in different interlayers to relieve the growth stress between the silicon carbide substrate and the aluminum nitride single crystal, and to grow In the process, the process of variable temperature and pressure is adopted to control the heating and cooling speed. The source body is from top to bottom, and the silicon carbide composition gradually decreases. By adjusting the concentration of silicon carbide in the source, the silicon carbide in the aluminum nitride single crystal is adjusted. content, so as to reduce the growth stress of aluminum nitride single crystal.

Description

technical field [0001] The invention relates to the field of growing aluminum nitride single crystals by a physical meteorological transmission method, in particular to a growth method for high-quality aluminum nitride single crystals. Background technique [0002] Aluminum nitride has a large band gap, up to 6.2eV, and high thermal conductivity. It is excellent as a light-emitting element in the ultraviolet region and a substrate material for electronic devices. Now the more common method of producing aluminum nitride single crystal is physical meteorological transport (PVT) method. Previously, the self-nucleation growth method was used to obtain aluminum nitride single crystals. However, due to the narrow growth window and high growth temperature of aluminum nitride single crystals, the current silicon carbide single crystal substrate can effectively control the crystal growth direction. However, the use of this heterogeneous substrate results in large thermal and lattice...

AI Technical Summary

Problems solved by technology

Such defects further degrade the crystal quality in AlN crystal growth, resulting in a large number of defects and even polycrystalline

Images