Ultra-pure nanometer silicon carbide and preparation method thereof

Abstract

The invention provides ultra-pure nanometer silicon carbide and a preparation method thereof. the preparation method comprises the following steps: preparation of a gas reaction precursor: mixing a carbonaceous gas and a silicon-containing gas at the Si:C molar ratio of 1: 1.0-1:1.06 to obtain the gas reaction precursor; preparation of ultra-pure nanometer silicon carbide: introducing the gas reaction precursor into a preheated ceramic reactor such that the gas reaction precursor is directly synthesized in a high-temperature zone of the ceramic reactor into nanometer silicon carbide with granularity of 50-500 nm. Temperature in the preheated ceramic reactor is 1100-2200 DEG C. pressure of the ceramic reactor is 1-5 atmospheric pressures. A single crystal form of nanometer silicon carbide can be synthesized in the invention.

Description

Technical field [0001] The invention relates to the technical field of silicon carbide nano materials, in particular to an ultra-pure nano silicon carbide and a preparation method thereof. Background technique [0002] Silicon carbide single crystal is ideal because of its unique characteristics such as large forbidden band width, high breakdown electric field, large thermal conductivity, high electron saturation drift speed, small dielectric constant, strong radiation resistance, and good chemical stability. One of the third generation semiconductors. At present, the most effective method for growing silicon carbide crystals is the physical vapor transport (PVT) method. Silicon carbide powder is the main raw material for growing semiconductor silicon carbide single crystals by PVT, and the purity of the raw materials directly affects the crystal quality and electrical properties of the grown single crystal The key factor of nature. When nano-silicon carbide is applied to nano-...

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Problems solved by technology

[0003] At present, the commonly used silicon carbide powder preparation method generally adopts the carbothermal reduction method of silicon dioxide or silicon powder, such as the secondary high-temperature synthesis method reported in the patent CN101302011A. The prepared silicon carbide powder is crushed, ground, pickled, and dried. , screening and other multiple processes, and finally only micron-sized silicon carbide can be obtained, and its comprehensive production cost is high

However, the gas phase synthesis of silicon carbide powder currently proposed, such as the method proposed by patents CN1184142C and CN102583382B, can only synthesize silicon carbide powder of mixed crystal forms

However, the nano-silicon carbide synthesized by the traditional high-temperature plasma method cannot synthesize single-crystal nano-silicon carbide powder due to the huge temperature gradient in the high-temperature plasma region.

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