Crucible for growing silicon carbide crystals by physical vapor transport

Abstract

The invention provides a crucible for growing a silicon carbide crystal through a physical vapor transport method. The crucible comprises a crucible body, wherein the crucible body comprises a bottom wall and a sidewall which encircle an inner chamber in which silicon carbide polycrystalline powder is stored; furthermore, an interlayer chamber for storing a silicon source is formed in the sidewall; the silicon source is used for supplying Si vapor pressure in the interlayer chamber, and the Si vapor pressure in the interlayer chamber is not less than that in the inner chamber. According to the crucible, the interlayer chamber is arranged in the sidewall of the crucible body, and the silicon source is positioned in the interlayer chamber and used for supplying proper Si vapor concentration, so that the spreading direction of Si vapor in a SiC monocrystal growing chamber can be controlled under the Si steam concentration gradient effect, and as a result, the stoichiometric ratio in the whole silicon carbide monocrystal growing process can be effectively controlled, and the defect that a carbonaceous inclusion is generated in the silicon carbide crystal can be avoided; moreover, raw materials can be prevented from serious carbonizing, and the high-quality silicon carbide growth can be promoted.

Description

technical field [0001] The invention relates to the technical field of silicon carbide crystal preparation, in particular to a crucible for growing silicon carbide crystals by a physical vapor transport method. Background technique [0002] Silicon carbide (SiC), as the third-generation wide-bandgap semiconductor material developed after Si and GaAs, has excellent physical and chemical properties such as large bandgap width, high critical breakdown electric field strength, high thermal conductivity, and good chemical stability. characteristic. SiC devices made of it are more suitable for harsh conditions such as high temperature, high frequency, high voltage, and strong radiation. Moreover, SiC has similar lattice constants and thermal collision coefficients to GaN and AlN, so SiC substrates are also used in the production of optoelectronics. Ideal substrate materials for devices and microwave power devices. Based on the above excellent physical and chemical properties, th...

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Problems solved by technology

However, the tantalum in the growth system will enter the SiC single crystal, which will introduce impurity pollution to the SiC single crystal; in addition, the graphite crucible is technically difficult and the metal carbide is expensive, especially for large-sized crystal crucibles, resulting in Increased production costs

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