SiC MOSFET reliability: Review of degradation mechanisms, failures, and enhancement strategies

This paper presents a comprehensive review of reliability challenges and degradation mechanisms of silicon carbide (SiC) power MOSFETs, with the objective of clarifying failure phySiCs, test methodologies, and mitigation strategies relevant to high performance power electronic applications. SiC MOSFETs offer superior material properties, including a wide bandgap (3.26 eV), high breakdown electric field (3 MV/cm), and high thermal conductivity (4.9 W/cm·K), enabling operation at high voltage, frequency, and temperature across electric vehicles, renewable energy, aerospace, and industrial systems. However, the rapid adoption of SiC technology has outpaced the development of mature reliability frameworks, leaving critical gaps in understanding long-term degradation under extreme electrical, thermal, and mechanical stresses. This review addresses key reliability concerns, including gate oxide degradation, short-circuit ruggedness, avalanche robustness, thermo-mechanical failure under power cycling, and body diode reliability. Each section explores both fundamental mechanisms and mitigation strategies. Additionally, experimental results from short circuit testing, Unclamped Inductive Switching (UIS) characterization, and body diode evaluation are presented to illustrate practical proofs of some reliability issues. It further incorporates reliability tests reported in standards and the automotive industry, while outlining diagnostic indicators at the device, package, and system levels, emphasizing their sensitivity and applicability. In addition, it examines emerging trends including AI-driven reliability prediction, advanced packaging, novel oxide technologies, and next generation device structures, offering a forward-looking roadmap for improving SiC MOSFET reliability.