Another way to investigate the characteristics of time-dependent dielectric breakdown of ultra-thin oxides

Comparing the characteristics of gate voltage shift (delta V/sub gw/) to time-dependent dielectric breakdown (i.e., TDDB), it is shown that both gate voltage shift (delta V/sub gw/) and TDDB are of a single mode in Weibull distribution, field acceleration factor and thermal activation energy are similar. Qualitatively, gate voltage shift and TDDB are caused by the same mechanism. Thus, the characteristics of TDDB can be manifested by the characteristics of V/sub gw/ degradation. The extrapolated lifetime from "E" model is more reasonable than that from "1/E" model. Like the lifetime extrapolation for TDDB, "1/E" model significantly overestimates the oxide lifetime.