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.