Surface-Potential-Based Silicon Carbide Power MOSFET Model for Circuit Simulation

Abstract

Transistor models have been playing a key role in designing efficient power converters. As the operating frequency of the converters becomes higher, transistor models need to represent physical device behavior accurately. This paper proposes a comprehensive surface-potential-based model of silicon carbide (SiC) power MOSFETs that realizes accurate circuit simulations. Whereas conventional simulation models are based on empirical formulas, the proposed model is constructed in a surface-potential-based framework by considering the physical structure and behavior of vertical power SiC MOSFETs. The proposed model represents both I-V and C-V characteristics from weak inversion to the high-power region. In addition, the proposed model calculates the channel mobility degradation due to SiC/SiO$_2$ interface traps, which significantly affects the circuit performance. Through experiments using a commercial SiC power MOSFET, excellent agreements are obtained between measurement and simulation in I-V and C-V characteristics at various temperatures for wide power ranges up to 1 kW. The transient behavior of a double-pulse tester is also well reproduced within a timing error of 12.6 ns even under the high temperature.