Preparation method and growth device of N-type silicon carbide crystal

Abstract

The invention provides a preparation method and a growth device of an N-type silicon carbide crystal. The method comprises the following steps: (1) placing a raw material in a high-temperature area of a crucible, placing a seed crystal in a low-temperature area of the crucible, recessing the outer wall of the top of the crucible inwards to form an annular gas groove, placing the assembled crucible in a furnace body of a crystal growth furnace, and enabling the annular air groove to be close to a vent hole of the furnace body; and (2) in a crystal growth stage, introducing nitrogen source gas into the furnace body through the vent hole, controlling crystal growth temperature and crystal growth pressure, and enabling the N-type silicon carbide crystal to grow on the seed crystal. The annular gas groove is close to the vent hole of the furnace body, the introduced gas can flow along the annular gas groove, a gas flow speed is high, the gas is diffused into the crucible, heat transmission away from the central axis in the crucible is accelerated, the radial temperature gradient of the crucible is reduced, and crystal growth quality is improved.

Description

technical field [0001] The invention relates to a preparation method and a growth device of an N-type silicon carbide crystal, belonging to the technical field of semiconductor material preparation. Background technique [0002] Silicon carbide materials have attracted extensive attention due to their excellent semi-insulating properties, especially for high-power semiconductor devices with special needs. Silicon carbide has become a potential material for these devices due to its high temperature, high frequency, and high power characteristics. . [0003] At present, the industrial production of silicon carbide crystals mostly adopts the PVT method for production, but due to the high requirements for its growth conditions, the defects introduced during the growth process limit its performance improvement and further application and development. Therefore, the improvement of defects has become the primary prerequisite for improving the quality of silicon carbide substrates....

AI Technical Summary

Problems solved by technology

For TSD and BPD, dislocation slip can occur, and when it hits a TED wall or other defects, the slip will stagnate, and dislocation accumulation will occur near the TED wall or defect, resulting in excessive local dislocation density of the SiC substrate , which seriously affects the performance and further application and development of silicon carbide crystals

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