Improving the Electrical Performances of 1200 V 4H-SiC MOSFETs by Optimizing the Doping Dose of p-Well

In order to better optimize the p-well doping concentration, the p-well is divided into p-well-A and p-well-B. The doping concentration of these two regions has contradictory effects on the threshold voltage, conduction characteristics, blocking voltage and mobility of the device. So, the effect of doping dose ofp-well-A and p-well-B on the electrical characteristics of 1200 V 4H-SiC power MOSFETs is studied. 1200 V 4H-SiC MOSFETs with four kinds of doping dose of p-well are experimented. The blocking, transfer and output characteristics of the fabricated 1200 V 4H-SiC MOSFETs are performed. In addition, TCAD simulations are used to support and clarify the experimental results. The results show that optimizing the doping concentration of p-well-B can make the device obtain better threshold voltage and conduction characteristics, and ensure that the blocking voltage meets the requirements and does not deteriorate the mobility.