Interplay of voltage and temperature acceleration of oxide breakdown for ultra-thin oxides

In this work, we unequivocally demonstrate that strong temperature dependen ce of time(charge)-to-breakdown T-BD/Q(BD) observed on ultra-thin oxides is not a thickness effect but rather a consequence of two experimental facts: (1) voltage-dependent voltage acceleration and (2) temperature-independent voltage acceleration within a fixed T-BD window. By extending down to -30 degreesC, we found non-Arrhenius temperature dependence is a totally indepe ndent effect. Based on our statistically accurate experimental database, we found that defect-generation rate and critical defect density as commonly measured using stress-induced leak-age current (SILC) only show a change of two orders of magnitude and no change, respectively. Weibull slopes are al so found to be temperature-independent. We propose an alternative model of two-step hydrogen degradation to explain these experimental results. (C) 20 01 Published by Elsevier Science B.V.