Characterization of time-dependent dielectric breakdown in intrinsic thin SiO 2

Abstract

Time-dependent dielectric breakdown data collected from 6.5-, 9-, 15-, 20- and 22.5-nm-thick SiO 2 films are presented. The failure distributions are of single mode with no apparent extrinsic population. The logarithm of the median-test-time-to failure, log( t 50), is described by a linear electric field dependence. Contrary to reports in earlier studies, the field acceleration parameter is observed to be insensitive to temperature and has a value of approximately 1.0 decade MV −1 cm −1 for the range of oxide thicknesses studied. Capacitance-voltage studies indicate that there is no strong correlation between oxide trapped charges and time to failure under constant voltage stress conditions.