A kind of silicon carbide powder material and its preparation method, using device

Abstract

The application discloses a silicon carbide powder, a preparation method thereof, and a device used, belonging to the field of semiconductor material preparation. The preparation method of the silicon carbide powder comprises the following steps: after removing impurities from the carbon powder at 1800-2000°C, injecting silane gas into the carbon powder under an inert gas environment, and performing primary synthesis and secondary synthesis in the synthesis chamber Finally, silicon carbide powder is obtained; wherein, the primary synthesis includes: feeding silane gas into the synthesis chamber with X flow rate, at a pressure of 500-800mbar and a temperature of 1800-2300°C, the primary synthesis time t1 is 5- 25h; the secondary synthesis includes: feeding silane gas into the synthesis chamber at a flow rate of X+Y*△t, at a pressure of 500-800mbar and a temperature of 1800-2300°C, the secondary synthesis time t2 is 45-125h ; Wherein, the Y is a positive number, and Δt is 0-t2 which increases with time. The silicon carbide powder prepared by the silicon carbide powder preparation method has high purity and uniform particle size, and the particle diameter of the obtained silicon carbide powder can be adjusted.

Description

technical field [0001] The application relates to a silicon carbide powder, a preparation method thereof, and a device used, belonging to the field of semiconductor material preparation. Background technique [0002] Silicon carbide is a typical wide bandgap semiconductor material and one of the representatives of the third generation of semiconductor materials after silicon and gallium arsenide. Silicon carbide materials have excellent characteristics such as high thermal conductivity, high breakdown field strength, and high saturation electron mobility, and have become one of the popular materials for preparing high-temperature, high-frequency, high-power and radiation-resistant devices. It is widely used in civil lighting, screen display, aerospace, high temperature radiation environment, oil exploration, radar communication and automotive electronics and other fields. [0003] At present, the preparation of silicon carbide powder is mainly realized by self-propagating h...

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Problems solved by technology

However, this method needs to add additional auxiliary reagents to maintain it, which will inevitably cause contamination by foreign impurities, making it difficult to synthesize high-purity silicon carbide powder, and due to the difference in crucible radial and axial temperatures, resulting There is a big difference in the particle size of the synthesized silicon carbide powder

The uneven particle size of silicon carbide powder will cause a large difference in powder bulk density during the growth of silicon carbide single crystal, resulting in an increase in the inhomogeneity of the temperature field, an increase in the internal stress of silicon carbide single crystal, and even large defects such as polymorphism and micropipes. output

[0004] In addition, the melting point of raw material silicon for the preparation of silicon carbide powder is low, and the temperature before the reaction needs to be kept at a low temperature to avoid the melting and sublimation of silicon, which will cause the impurities absorbed by the insulation materials in the furnace cavity to be unable to be released before the reaction. Discharge, thus inevitably participating in the reaction, resulting in a decrease in the purity of the synthetic silicon carbide powder

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