Comparison of the influence of p-body region on electrical characteristics of planar and trench gate SiC MOSFET

Abstract As the core power device of the third-generation semiconductor, the performance difference between the trench gate and planar gate structures of silicon carbide (SiC) MOSFET directly affects the reliability of the device and the industrialization process. In this study, through the TCAD simulation and quantitative analysis system, the sensitivity difference and physical mechanism of the threshold voltage and output current of two types of structure to the doping concentration and depth of the p-body region are revealed. Since the output current magnitudes of the two structures are different, an elasticity coefficient is introduced to quantify the sensitivity of the output current to the parameters of the p-body region. The sensitivity of the threshold voltage to the parameters of the p-body region is analyzed using linear regression. The results show that the output current and threshold voltage of planar gate devices are more sensitive to the variation of doping concentration, while those of trench gate devices are more sensitive to the variation of depth. This difference stems from the fact that different channel directions result in different influences of specific parameters on the space charge in the depletion region and the carrier mobility in the channel.