Model Development for Threshold Voltage Stability Dependent on High Temperature Operations in Wide-Bandgap GaN-Based HEMT Power Devices

Abstract

Temperature-dependent threshold voltage (<i>V</i>_th) stability is a significant issue in the practical application of semi-conductor power devices, especially when they are undergoing a repeated high-temperature operation condition. The <i>V</i>_th analytical model and its stability are dependent on high-temperature operations in wide-bandgap gallium nitride (GaN)-based high electron mobility transistor (HEMT) devices that were investigated in this work. The temperature effects on the physical parameters-such as barrier height, conduction band, and polarization charge-were analysed to understand the mechanism of <i>V</i>_th stability. The <i>V</i>_th analytical model under high-temperature operation was then proposed and developed to study the measurement temperatures and repeated rounds dependent on <i>V</i>_th stability. The validity of the model was verified by comparing the theoretical calculation data with the experimental measurement and technology computer-aided design (TCAD) simulation results. This work provides an effective theoretical reference on the <i>V</i>_th stability of power devices in practical, high-temperature applications.