Role of Oxygen Vacancies in Short- and Long-Term Instability of Negative Bias-Temperature Stressed SiC MOSFETs

We use hybrid-functional density functional theory to study the role of oxygen vacancies in negative bias-and-temperature stress-induced threshold voltage instability in 4H-silicon carbide power MOSFETs. According to our model, certain originally electrically “inactive” oxygen vacancies are structurally transformed into electrically “active” defects in the presence of strong negative bias and temp...