Electric breakdowns and breakdown mechanisms in ultrathin silicon oxides

It was found that the breakdown times measured using time-dependent-dielect ric-breakdown (TDDB) distributions could be shifted to shorter times when t he amount of energy available during the breakdown event was increased. The TDDB distributions were non-unique and breakdown models must account for b oth electrical breakdowns and dielectric breakdown. A novel approach for ob taining breakdown distributions will be presented. This approach uses a sma ll number of oxides to obtain a time-dependent-electric-breakdown (TDEB) di stribution, which will be shown to provide complementary information to tha t obtained from (TDDB) distributions. While the observation of dielectric b reakdown in ultra-thin dielectrics may be difficult using standard test con ditions, it will be shown that electric breakdowns are relatively easy to o bserve. (C) 1999 Elsevier Science Ltd. All rights reserved.