Silvaco-based evaluation of 10 kV 4H-SiC MOSFET as a solid-state switch in narrow-pulse application

Key requirements for a solid state switch in a fast switching pulsed power circuit include high blocking voltage, high current conduction and fast switching capability. Typical pulsed power applications like plasma initiation and high-energy LASER require operating voltages in the order of several kilovolts. The development of a multi-kilovolt SiC MOSFET for fast switching pulsed power application would require detailed analysis of the device switching characteristics. Since the switching speed of a MOSFET is primarily dependent on the inter-electrode capacitances, it becomes critical to have a comprehensive understanding of the device capacitance and its effect on the gate driver requirements for narrow-pulse switching. In this research, 2D model of a 10 kV 4H-SiC MOSFET was developed using Silvaco ATLAS TCAD software and simulated for its steady state, AC, and transient characteristics. The device cell was designed for an active area of 5 μm² and 100 A/cm² drain current density. The capacitance-voltage and gate charge curve for the SiC MOSFET were obtained via AC and transient simulation respectively. This data was used to estimate the gate drive requirements for the device under fast switching conditions.