Accelerated testing of time-dependent breakdown of SiO2

Electric-field acceleration factor β is the slope of the
\log (t_{BD})
versus E
ox
curve, where t
BD
is the time to breakdown at oxide field E
ox
. We report that β is not a constant but proportional to
E\min{ox}\max{-2}
. This is the main cause of the wide divergence of β values reported in the literature. The reported oxide thickness dependence of β is believed to be a result of the higher electron trap densities in thicker oxides. Oxide lifetime extrapolation using
\log (t_{BD})
, or better,
\log (Q_{BD})
against
1/E_{ox}
plots is more accurate and has a theoretical basis. Highly accelerated oxide testing appears to be feasible especially for very thin oxides.