A kind of synthesis furnace and synthesis method for preparing silicon carbide powder

Abstract

The application discloses a synthesis furnace and a synthesis method for preparing silicon carbide powder, belonging to the field of semiconductor material preparation. The silicon carbide powder synthesis furnace includes a furnace body, a crucible assembly and a heating element. The crucible assembly is placed in the furnace cavity formed by the furnace body. It is characterized in that the crucible assembly includes a crucible and a flow guide, and the crucible is provided with a primary air holes; the flow guide is arranged in the crucible cavity formed by the crucible, and the flow guide includes an air intake plate with a plurality of secondary air intake holes and a plurality of porous flow guide tubes respectively connected with the secondary air intake holes; the air intake plate The crucible chamber is divided into a buffer chamber and a synthesis chamber. After entering the first-stage air inlet, the raw material gas flows from the pores of the multi-hole guide pipe to the synthesis chamber along the path of the buffer chamber, the second air inlet and the porous guide pipe, and is combined with the The solid raw materials in the synthesis chamber react to produce silicon carbide powder. The silicon carbide powder prepared by the silicon carbide powder synthesis furnace has high purity and uniform particle size, and the particle size of the obtained silicon carbide powder can be adjusted.

Description

technical field [0001] The application relates to a synthesis furnace and a synthesis method for preparing silicon carbide powder, 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-propaga...

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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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