Growth method and device of high-quality silicon carbide crystal

Abstract

The invention provides a growth method and device of a high-quality silicon carbide crystal. The method comprises the following steps: (1) an assembling stage; (2) heating stage; (3) nucleation stage: keeping the temperature of the center of the top end of the crucible at T1, controlling the thermal insulation cover to move downwards along the side wall of the thermal insulation cylinder, and controlling the temperature difference between the temperature of the center of the top end of the crucible and the temperature of the edge of the top end of the crucible to be gradually increased to deltaT2 so that the silicon carbide raw material gas phase is transmitted to the seed crystal for nucleation; and (4) growth stage: transmitting the silicon carbide raw material gas phase to the seed crystal for crystal growth. In the nucleation stage, an annular temperature field with the center of the seed crystal as the circle center is formed on the surface of the seed crystal, the heat preservation cover is controlled to move downwards, the annular temperature field is more uniform and stable, the radial temperature gradient is gradually and slowly increased, directional quantitative adjustment of the radial temperature gradient is achieved, the radial temperature gradient at the seed crystal is gradually increased, and multi-core competition and merging in the nucleation stage are promoted through the combined action; uniform and compact growth steps are formed, the generation probability of crystal defects is reduced, and the crystal growth quality is improved.

Description

technical field [0001] The invention relates to a high-quality silicon carbide crystal growth method and device, belonging to the technical field of semiconductor material preparation. Background technique [0002] Silicon carbide crystal is a typical wide bandgap semiconductor material, and it is one of the representatives of the third generation of semiconductor materials after silicon and gallium arsenide. Silicon carbide crystal has excellent characteristics such as high thermal conductivity, high breakdown field strength, and high saturation electron mobility, and has become one of the popular materials for preparing high-temperature, high-frequency, high-power and radiation-resistant devices. [0003] Currently, silicon carbide growth methods mainly include physical vapor transport (PVT), liquid phase epitaxy (LPE), and chemical vapor deposition (CVD), among which PVT is the most mature method. The PVT method for growing silicon carbide crystal growth furnaces general...

AI Technical Summary

Problems solved by technology

In the early stage, the temperature field of silicon carbide crystal growth was unstable, which affected the quality of nucleation and directly affected the growth quality of silicon carbide crystals.

[0004] In the existing method of raising and lowering the crucible during the crystal growth process, the adjustment and control of the temperature field is realized by adjusting the position of the crucible, but the raising and lowering of the crucible will also seriously affect the uniformity and stability of the temperature field, disrupting the silicon carbide atmosphere. Orderly transmission, and will cause the silicon carbide powder in the crucible to vibrate and shift, significantly increase the probability of defects such as polymorphism and inclusions, and reduce the crystallization quality of silicon carbide, etc.

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