A Charge-to-Breakdown (QBD) Approach to SiC Gate Oxide Lifetime Extraction and Modeling

This paper proposes a charge-to-breakdown (Q
BD
) approach for SiC/SiO
2
dielectric lifetime extraction. The current through the dielectric is shown to be a combination of Fowler Nordheim (FN) and thermally assisted tunneling (TAT). The former leads to positive charge trapping, the latter to negative charge storage in border traps near the SiC/SiO
2
interface. Both degradation mechanisms have a distinctly different failure distribution function. Time-to-fail extracted from constant field TDDB (standard industry technique) is unable to capture the effects of these different charge trapping mechanisms on the failure distribution function, in contrast to constant current Q
BD
stress. Hence, time-to-fail from Q
BD
stress leads to a more accurate and physics based lifetime prediction.