Evaluating BTI Impact on SiC MOSFET Circuit Performance: A Physically Grounded Reliability Approach

This paper presents a reliability analysis of a DC-DC boost converter with a Silicon Carbide (SiC) power MOSFET as the switching element, focusing on the degradation induced by Bias Temperature Instability (BTI). The study emphasizes the long-term impact of BTI on one of the most critical device parameters: the ON-state resistance Ron, which increases over time due to a progressive threshold voltage (V th) shift. Unlike conventional approaches that rely on empirical power-law models, this work employs a physics-based charge trapping model to accurately predict ∆V th and its influence on conduction losses. The reliability simulator Comphy is used to extract BTI-induced parameter shifts under both DC and AC gate stress conditions, including recovery effects. These results are then integrated into SPICE-level simulations to evaluate the impact on circuit-level behavior and lifetime predictions. The findings demonstrate that omitting recovery effects or relying on empirical models can significantly misestimate power loss and temperature evolution, thus leading to inaccurate lifetime assessments. This study underlines the necessity of using physically grounded models for precise reliability evaluation of SiC-based power converters.