Temperature Dependent Analytical Model for the Threshold Voltage of the SiC VJFET with a Lateral Asymmetric Channel

Abstract

The wide-bandgap (WBG) semiconductor devices for modern power electronics require intensive efforts for the analysis of the critical aspects of their operation. In recent years, silicon carbide (SiC) based field effect transistor have been extensively investigated. Motivated by the significant employment of the SiC Vertical Junction Field Effect transistors with lateral channel (LC-VJFET) in the development of high-voltage and high temperature applications, the properties of the LC-VJFET device are investigated in this work. The most important normally-ON LC-VJFET parameter is their threshold voltage (VTh), which is defined as the gate-to-source voltage necessary to block the device. The higher complexity of the blocking operation of the normally-ON device makes the accurate knowledge of the VTh as a fundamental issue. In this paper, a temperature dependent analytical model for the threshold voltage of the normally-ON LC-VJFET is developed. This analytical model is derived based on a numerical analysis of the electrical potential distribution along the asymmetrical lateral channel in the blocking operation. To validate our model, the analytical results are compared to 2D numerical simulations and experimental results for a wide temperature range.