High-quality aluminum nitride monocrystal growth method

Abstract

The invention discloses a high-quality aluminum nitride monocrystal growth method. The method comprises the steps that an initial deposition layer adopts a large aluminum nitride / silicon carbide mixedfilling mode, then, high-purity aluminum nitride powder is adopted, temperature and pressure are changed in the growth process, and aluminum nitride filling layers in a crucible include the first aluminum nitride powder layer, the second aluminum nitride sintered granular layer, the third aluminum nitride and silicon carbide granular mixture layer and the fourth aluminum nitride and silicon carbide granular mixture source layer from bottom to top. The silicon carbide powder is mixed into the aluminum nitride powder, and different silicon carbides are adopted in different interlayers, due to the ratio of aluminum nitride, the growth strain between a silicon carbide substrate and the aluminum nitride monocrystal is relieved, the temperature and pressure changing technology is adopted in thegrowth process, the temperature increase and decrease speed is controlled, material source bodies are arranged from top to bottom, the content of silicon carbide is gradually lowered, the concentration of the silicon carbide in the material sources is adjusted so as to adjust the content of silicon carbide in the aluminum nitride monocrystal, and therefore the growth strain of the aluminum nitride monocrystal is lowered.

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...

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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

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