Graphite thermal-field single crystal growth device for preparing silicon carbide crystals

Abstract

The invention discloses a graphite thermal-field single crystal growth device for preparing silicon carbide crystals, belonging to the technical field of silicon carbide single crystal preparation and crystal growth. The graphite thermal-field single crystal growth device comprises a sealing cavity, a heating structure, a heat preservation structure, a temperature adjusting structure, a crucible and a temperature measuring mechanism, wherein the heat preservation structure is arranged in the sealing cavity; the heating structure is arranged in the heat preservation structure; the temperature measuring mechanism is arranged on the sealing cavity; the temperature adjusting structure is arranged in the heat preservation structure, and a crucible and a seed crystal support are arranged in the heat preservation structure; the heating structure is used for heating the bottom and the top of the crucible and carrying out axial and radial temperature control on the crucible; the temperature measuring mechanism is used for respectively measuring the temperatures of the top and the bottom of the crucible; the heat preservation structure is used for carrying out heat preservation on a thermal field of the whole cavity, so heat loss of the crucible can be reduced, and accurate temperature control on each part of the crucible is realized; the temperature adjusting structure can reduce the radial temperature gradient of the crucible; and therefore, the radial temperature gradient and the stress gradient of the crystal in the growth process of the silicon carbide single crystal are reduced, the defects of crystal growth can be reduced, and the quality of the crystal is ensured.

Description

technical field [0001] The invention relates to the technical field of silicon carbide single crystal preparation and crystal growth, in particular to a graphite thermal field single crystal growth device for preparing silicon carbide crystals. Background technique [0002] Silicon carbide is a high-quality wide-bandgap semiconductor material, which has the advantages of wide bandgap, high breakdown electric field, high thermal conductivity, high saturation electron drift rate, etc., and can meet the needs of high temperature, high power, low loss and large diameter devices. Silicon carbide single crystals cannot be formed by the melting method, and the sublimation growth technology based on the improved Lely method - physical vapor transport method is a common method to obtain silicon carbide single crystals. The growth principle of silicon carbide single crystal prepared by PVT method is: high-purity silicon carbide powder source decomposes at high temperature to form gase...

AI Technical Summary

Problems solved by technology

In the prior art, the heating resistors are generally located at the bottom and surroundings of the crucible, so that the crucible has a relatively good temperature gradient in the axial direction, and this heating method will cause a large temperature gradient in the radial direction of the seed crystal.

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