High-quality high-purity semi-insulating silicon carbide single crystal, substrate and preparation method thereof

Abstract

The invention discloses a high-quality high-purity semi-insulating silicon carbide single crystal, a substrate and a preparation method thereof and belongs to the field of semiconductor materials. Thepreparation method of the high-quality high-purity semi-insulating silicon carbide single crystal comprises the following steps: putting a silicon carbide raw material into a crucible, performing sublimation so as to obtain a sublimation raw material, and conveying the sublimation raw material into a primary seed crystal through an axial temperature gradient gas phase in the crucible to implementprimary crystal growth, so as to obtain the high-quality high-purity semi-insulating silicon carbide single crystal, wherein at least one transition seed crystal is arranged between the silicon carbide raw material and the primary seed crystal; and with the transition seed crystal, at least a part of the sublimation raw material has a single crystal growth-resublimation process once. By adoptingthe preparation method disclosed by the invention, the semi-insulating silicon carbide single crystal of a very high purity can be prepared from the silicon carbide raw material of a low purity, meanwhile, the growth quality of the high-purity semi-insulating silicon carbide single crystal can be also taken into account, and the production cost is low; and in addition, the high-purity semi-insulating silicon carbide single crystal and the substrate thereof disclosed by the invention are free of or slight in defect, high in purity, high in quality and good in uniformity.

Description

technical field [0001] The application relates to a high-quality and high-purity semi-insulating silicon carbide single crystal, a substrate and a preparation method thereof, belonging to the field of semiconductor materials. Background technique [0002] Silicon carbide single crystal has excellent physical properties such as large band gap, high thermal conductivity, and high critical breakdown field strength. In particular, the high-purity semi-insulating silicon carbide single crystal substrate has the characteristics of high purity and high resistivity, which can effectively reduce the dielectric loss of the device and reduce the parasitic effect at high frequencies, so it becomes the preferred material for high-frequency and microwave devices. [0003] The technical difficulty in the preparation of high-purity semi-insulating silicon carbide single crystal lies in the control of purity and quality. The growth of high-purity silicon carbide single crystals first requir...

AI Technical Summary

Problems solved by technology

The growth of high-purity silicon carbide single crystals first requires high-purity silicon carbide powder, and impurities such as nitrogen, boron, and aluminum in silicon carbide powder are not easy to remove

Secondly, silicon carbide powder is continuously lost with the growth of silicon carbide single crystal, which causes the quality change of silicon carbide crystal during the growth process of silicon carbide single crystal, which affects the consistency and stability of silicon carbide single crystal quality

[0004] At present, the preparation technology of high-purity silicon carbide powder is still difficult. The impurities in silicon carbide powder will still be released during the sublimation process and introduced into silicon carbide single crystal, which will affect the purity and resistivity of silicon carbide single crystal. Key Performance Indicators

Existing technologies cannot fully meet the powder purity requirements of the existing high-purity semi-insulating silicon carbide single crystal, and the preparation cost of high-purity

Images