Heavy-Ion Effects in SiC Power MOSFETs With Different Gate Oxide Thicknesses

Abstract

Heavy-ion-induced single-event leakage current (SELC) in silicon carbide (SiC) power MOSFETs is investigated. Our experimental data for 1200 V SiC power MOSFETs with varying gate oxide thicknesses reveal that a thicker oxide reduces SELC in the drain–gate path but increases SELC in the drain–source path, suggesting a redistribution of damage in the device. Based on these experimental results, we propose the Lightning Leader model. This model suggests that a conductive path formed by heavy-ion passing through the gate oxide diverts current flow from the source to the low-resistance path in the gate, thereby mitigating damage to the source p–n junction region and altering the overall damage distribution in the SiC power MOSFET. Besides, we also discuss the SELC step extraction method as well as the impact of micro-dose effect and its annealing behavior.