Growth method of silicon carbide crystal grown by pvt method

Abstract

The invention provides a method for growing silicon carbide crystals by a PVT method, the method comprising: providing a crucible; placing a silicon carbide raw material and a seed crystal in the crucible; putting the crucible into a growth chamber and vacuuming it, and then introducing a protective gas , set the temperature of the chamber; when the temperature rises to the first preset temperature, the chlorine-containing gas is introduced through the degassing device in the crucible, the temperature rises to the second preset temperature, and the feeding is stopped or continued for the first preset time Chlorine-containing gas; the temperature rises to a third preset temperature, and after the silicon carbide crystals start to grow for a second preset time, silicon carbide crystals are obtained by annealing. This growth method can effectively control the release rate and uniformity of chlorine-containing gas, and avoid crystallization defects caused by the condensation of gas-phase silicon on the crystal surface; by controlling the time and flow rate of chlorine-containing gas, crystallization defects can be further avoided; the placement of porous graphite blocks It can make the excess chlorine-containing gas introduced and the carbon particles suspended in the growth atmosphere escape, and reduce the carbon inclusion defects in the crystal.

Description

technical field [0001] The invention relates to the technical field of silicon carbide crystal preparation, in particular to a method for growing silicon carbide crystals by a PVT method. Background technique [0002] Compared with silicon-based semiconductors, the third-generation semiconductors represented by silicon carbide have the characteristics of forbidden bandwidth, high saturated electron mobility, high breakdown electric field strength, and high thermal conductivity. They have high frequency, high temperature resistance, chemical corrosion resistance, High efficiency, strong radiation resistance, high pressure resistance and other superior performance, with the increasingly mature silicon carbide semiconductor preparation technology, will increasingly become an Supporting materials for core electronic devices in fields such as petroleum exploration and production. [0003] Silicon carbide crystal preparation methods include high temperature chemical vapor deposit...

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Problems solved by technology

[0014] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a growth method for growing silicon carbide crystals by PVT method, which is used to solve the problem of silicon-rich vapor deposition on the crystal when the PVT method is used to form silicon carbide crystals in the prior art. The surface condenses into silicon droplets to form crystallization defects, resulting in problems such as lower quality of silicon carbide crystal growth

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