Post-Irradiation-Gate-Stress on Power MOSFETs: Quantification of Latent Defects-Induced Reliability Degradation

On the Use of Post-Irradiation-Gate-Stress Results to Refine Sensitive Operating Area Determination

“…However, since the commercial device oxides studied previously [15] are 100% thicker that the radiation hardened device oxides studied here, we can assume that the different in the reliability can be explained by the difference in gate oxide thickness.…”

“…The difference between the 50% values for pristine and irradiated devices is about 15%. Previously, the measured reliability of commercial devices was about 30% in the worst case with no applied bias, and did not exceeded 20% when devices were irradiated with a negative gate voltage [15].…”

“…3(a)). These negative values appear to be a consequence of a heavy ion impact in a region of the gate oxide [15]. SEGR occurs with different bias conditions (from B-5 to B-8) but mainly with B-7 and B-8 bias conditions (14 devices over 16: 90%).…”

“…3(a) and (b) show typical current curves of irradiated devices that have undergone SEGR. According to variation of the currents ( , and ) on these curves, ion impact position can be established on those devices after irradiation and PGST [15]. Fig.…”

“…Recently, we reported results regarding latent defect creation after irradiation on two commercial devices (IRF130 and IRF140) [15]. In that study, we concluded that premature gate breakdown induced by the heavy ion is related to partial SEGR and not due to latent defect formation.…”