Evaluation of Burn-in Technique on Gate Oxide Reliability in Commercial SiC MOSFETs.

This work investigates the behavior of threshold voltage $(\mathbf{V}_{\mathbf{th}})$ , subthreshold swing (SS), and interface state density $(\mathbf{D}_{\mathbf{it}})$ of commercial SiC planar MOSFETs during the gate oxide burn-in process. The results indicate that prolonged oxide electric field $(\mathbf{E}_{\mathbf{ox}})$ stress can lead to defect generation at or near the SiC/SiO 2 interface, which degrades the reliability of the gate oxide. This study aims to determine the critical stress time for different values of $\mathbf{E}_{\mathbf{ox}}$ (used for burn-in) to mitigate excessive $\mathbf{V}_{\mathbf{th}}$ shift caused by the increase of $\mathbf{D}_{\mathbf{it}}$ in SiC MOSFETs. The research approach employed in this paper offers insights for the optimization of burn-in techniques in the industry, with the objective of reducing $\mathbf{V}_{\mathbf{th}}$ shift and preventing the degradation of the intrinsic lifetime of gate oxide while ensuring efficiency.