Silicon carbide single crystal growth equipment with function of adjusting ratio of carbon to silicon in growth atmosphere

Abstract

The invention discloses silicon carbide single crystal growth equipment with a function of adjusting the ratio of carbon to silicon in a growth atmosphere, which comprises a quartz tube, an induction coil and a graphite crucible, the graphite crucible comprises a silicon carbide powder heating area, a growth chamber and a seed crystal support, a second cover plate and a third cover plate are further arranged between the silicon carbide powder heating area and the growth chamber, and a vertical air pipe penetrating through silicon carbide powder is arranged at the bottom of the silicon carbide powder heating area. According to the technical scheme, the structure that the bottom structure of the graphite crucible is matched with a multiple cover plates is adopted, multi-space separation of the silicon carbide powder heating area is achieved, the output path of gas components after sublimation of the silicon carbide powder is changed, sublimation gas passes through the silicon carbide powder multiple times and forms a continuous large cycle, the silicon carbide powder is repeatedly heated for multiple times, the sublimation speed of the silicon-rich component gas and the sublimation speed of the carbon-rich component gas are coordinated, and then the high-quality silicon carbide single crystal is obtained.

Description

technical field [0001] The invention relates to the field of silicon carbide single crystal growth, and more particularly relates to a silicon carbide single crystal growth device with the function of adjusting the ratio of carbon to silicon in a growth atmosphere. Background technique [0002] Silicon carbide is a typical representative of the third-generation semiconductor material. At present, the growth technology of silicon carbide is mainly based on physical vapor transport (PVT). The principle is to heat the graphite crucible as a whole by means of heating coil induction. High, the top seed crystal temperature is low, so that the axial temperature gradient is formed inside the crucible, and the silicon carbide powder is heated and sublimated at the bottom of the crucible to realize the growth of silicon carbide single crystal on the seed crystal growth surface. [0003] In the early stage of silicon carbide single crystal growth, the silicon component will be preferen...

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Problems solved by technology

[0003] In the early stage of silicon carbide single crystal growth, the silicon component will be preferentially sublimated in the crucible, making the relative silicon content in the silicon carbide powder lower and lower, resulting in the remaining unsublimated silicon carbide in the silicon carbide powder in the middle and late stages of silicon carbide crystal growth. The powder becomes more and more carbon-rich, and the ratio of carbon to silicon in the growth atmosphere greatly exceeds 1:1, resulting in low silicon flow at the growth surface of the seed crystal, carbonization on the growth surface, and resulting silicon carbide monoliths. The problem of increased defects in the crystal

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