Silicon carbide single crystal growth graphite crucible capable of adjusting ratio of carbon to silicon in growth atmosphere

Abstract

The invention discloses a silicon carbide single crystal growth graphite crucible capable of adjusting a ratio of carbon to silicon in a growth atmosphere. According to the invention, a cavity of the graphite crucible comprises a crucible raw material cavity and a crucible growth cavity, and the thickness of the graphite wall of the crucible raw material cavity is greater than the thickness of the graphite wall of the crucible growth cavity; the crucible raw material cavity comprises a silicon carbide powder cavity and at least two silicon powder cavities; and the top of the silicon powder cavity is connected with a silicon powder conveying pipe, and the silicon powder conveying pipe is also connected with a silicon powder bin outside the graphite crucible. According to the invention, the growth atmosphere can be adjusted by consuming certain gas-phase silicon in the growth process of a silicon carbide single crystal, and the ratio of carbon to silicon in the growth process of the silicon carbide single crystal is kept in an optimal range, so silicon liquid drops are prevented from appearing on the growth surface of the silicon carbide single crystal, and the growth quality of the silicon carbide single crystal is further improved.

Description

technical field [0001] The invention belongs to the field of silicon carbide single crystal growth equipment, and more specifically relates to a silicon carbide single crystal growth graphite crucible capable of adjusting the ratio of carbon to silicon in a growth atmosphere. Background technique [0002] As the third-generation semiconductor, silicon carbide is the most mature wide-bandgap semiconductor material at present. It has energy bandwidth, high thermal conductivity, high saturation drift velocity of electrons, high critical breakdown electric field, low dielectric constant, and chemical stability. Good performance and other characteristics, can produce high-temperature, high-frequency, high-power, high-speed and radiation-resistant devices with more excellent performance, and can be widely used in aerospace exploration, nuclear energy development, electric vehicles, hybrid vehicles, rail transit, high-frequency devices, Microwave devices, etc., have broad applicati...

AI Technical Summary

Problems solved by technology

This will affect the growth quality of silicon carbide single crystal

[0004] Therefore, in the early stage of growth, since the chemical activity of the silicon atoms inside the liquid-phase silicon is stronger than that of the silicon atoms in the already crystallized silicon carbide, when the liquid-phase silicon is free on the surface of the silicon carbide crystal, the carbon atoms near it have and liquid phase The trend of silicon fusion will produce defects in the crystal; in the later stage of growth, due to the rich carbon in the silicon carbide powder, the flow rate of silicon on the surface of the silicon carbide seed crystal will be low, and the growth surface will be carbonized, which will also cause defects in the crystal

[0005] At the same time, as the crystal size increases, the medium-frequency induction heating in the crucible tends to fluctuate, making it difficult to maintain a stable temperature field for crystal growth, which is not conducive to the stable growth of crystals

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