Effect of vanadium doping on carrier transport dynamics in silicon carbide

Due to silicon carbide (SiC) power devices’ superior performance in terms of switching frequency, loss, and so on, they are widely used in high-power and high-frequency electronics. While SiC devices are in blocking mode, the transport and accumulation of charge carriers in SiC may lead to significant degradation and failure of semiconductor materials, which is the primary factor limiting their application in high-voltage and large-current fields. In addition, transition metal vanadium is often used to compensate for the defect levels in SiC, leading to more complex carrier transport dynamics behaviors. In this research, the effect of vanadium doping on the withstand voltage properties of SiC was explored. Firstly, characterization experiments, including x-ray diffraction, Raman spectroscopy, and Kelvin probe force microscopy on SiC before and after vanadium doping, were performed. Secondly, the transport dynamics of charge carriers in SiC were studied. Based on the influence of vanadium on the trap characteristics, the effect mechanism of vanadium doping on carrier transport dynamic behaviors was elucidated. Finally, the relationship between microscopic carrier transport and macroscopic dielectric properties was discussed. The results show that vanadium doped SiC introduces deep energy level traps, which are able to capture carriers and cause charge accumulation, inhibit carrier migration. This can also affect conductance current. Therefore, vanadium doping can effectively improve the voltage withstand capability of SiC in blocking mode by regulating the trap characteristics and carrier transport behaviors.