Threshold Voltage Temperature Dependence for a 1.2 kV SiC MOSFET with Non-Linear Gate Stack

The use of Silicon Carbide (SiC) power MOSFETs is becoming increasingly popular due to their unique properties, including a wide bandgap, higher critical electric field, and superior thermal conductivity compared to traditional Silicon (Si) MOSFETs. The reliability assessment of SiC power MOSFETs holds significant importance across various industries, such as automotive and aerospace, where these devices find numerous applications. One crucial aspect of their reliability is evaluating their performance during short-circuit (SC) events. To address this concern, this study employs TCAD simulations to analyze the behaviour of a SiC power MOSFET equipped with a gate insulator that consists of a stack of silicon dioxide (SiO2) combined with a non-linear dielectric (NLD) material. This NLD exhibits a Curie-Weiss temperature dependence, characteristic of ferroelectric materials. During short-circuit events, failures are often associated with temperature rises. The study demonstrates the effectiveness of using an NLD with a temperature-dependent permittivity (ε) as a gate insulator. By doing so, the temperature increase is mitigated, and the MOSFET's ruggedness during short-circuit events is enhanced. This advancement in gate insulator technology could significantly improve the overall reliability and performance of SiC power MOSFETs in various applications.