Preparation method of semi-insulating silicon carbide single crystal wafer

Abstract

The invention provides a preparation method of a semi-insulating silicon carbide single crystal wafer, and belongs to the technical field of production and processing of single crystal silicon. The silicon carbide wafer is irradiated by adopting high-energy particles, and point defects into the silicon carbide wafer is introduced to compensate shallow energy level defects of the silicon carbide wafer; the Al impurity concentration in the silicon carbide wafer is less than 1E15cm<-3>, the B and N shallow impurity concentrations are respectively less than 5E16cm<-3>, and the adopted high-energy particle irradiation dose is 0.3-25MeV; and the irradiation time is 0.1 to 6 hours. According to the invention, the actual difficulty of realizing uniform distribution of resistivity in and among semi-insulating SiC wafers under the condition that a deep-energy-level metal dopant is not used is overcome, the performance of a radio frequency device can be effectively improved, and meanwhile, the product consistency can be improved.

Description

technical field [0001] The invention belongs to the technical field of single crystal silicon production and processing, and relates to a method for preparing a semi-insulating silicon carbide single crystal wafer. Background technique [0002] As a wide bandgap semiconductor material, silicon carbide (SiC) has excellent physical properties such as high breakdown field strength, high operating temperature, high electron saturation migration rate and high thermal conductivity. ideal material for devices. Especially in the field of radio frequency, GaN radio frequency devices prepared on semi-insulating SiC single crystal wafers can handle at least 5 times the power of devices made of GaAs materials. For RF devices, a high-resistivity ("semi-insulating") substrate is generally required for coupling connections. Once the substrate is conductive, the frequency of the RF device will cause serious problems. After calculation, the minimum resistivity value of the passive performa...

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Problems solved by technology

However, the concentration of point defects that can be increased by the annealing process is small, and at the same time requires a huge cooling rate. This process has low production efficiency, and the concentration of impurities such as B and N in the SiC crystal will also decrease with the growth time. The uniformity of resistivity within and between SiC wafers is difficult to control

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