Method and device for preparing high-quality silicon carbide single crystal

Abstract

The invention provides a method and device for preparing a high-quality silicon carbide single crystal. The method comprises the following steps: (1) an assembling stage; (2) a first crystal growth stage: controlling the first through hole and the second through hole to be in a dislocation state, so that the raw material gas phase in a first crucible is transmitted to the seed crystal for crystalgrowth; and (3) a second crystal growth stage: when the silicon-carbon ratio in the gas-phase component in the first crucible is less than 1.1, controlling the first through hole and the second through hole to be in an at least partially overlapped state, so that the raw material in a second crucible is transmitted to the seed crystal through the first through hole and the second through hole in agas-phase manner for crystal growth. Raw materials in the second crucible are controlled to be conveyed to the seed crystal direction through the first through hole and the second through hole. Because the gas-phase component in the second crucible in the crystal growth stage is the silicon-rich atmosphere, the defect that the silicon atmosphere in the gas-phase component in the first crucible isinsufficient can be overcome, the problem of silicon-carbon ratio imbalance can be well solved, and the defects of microtubes, inclusions and the like in the crystal growth process are avoided.

Description

technical field [0001] The invention relates to a method for preparing a high-quality silicon carbide single crystal, belonging to the technical field of crystal growth. Background technique [0002] Silicon carbide (SiC) single crystal has excellent semiconductor physical properties such as high thermal conductivity, high breakdown voltage, extremely high carrier mobility, and high chemical stability, and can be made into high-frequency semiconductors that work under high temperature and strong radiation conditions. , High-power electronic devices and optoelectronic devices have great application value in the fields of national defense, high technology, industrial production, power supply, and transformation, and are regarded as the third-generation wide-bandgap semiconductor materials with great development prospects. [0003] The growth process of silicon carbide single crystal grown by PVT method is carried out in a closed graphite crucible, so the growth environment at ...

AI Technical Summary

Problems solved by technology

In this method, the flow rate of the silicon atmosphere cannot be flexibly controlled, which may cause too much silicon atmosphere in the growth chamber, and easily cause defects such as silicon coatings and micropipes.

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