Bipolar current stressing and electrical recovery of quasi-breakdown in thin gate oxides

The quasi-breakdown mechanism (QB) of thin gate oxides is investigated under bipolar constant current stressing. It was observed that there exist two distinct stages in quasi-breakdown (QB), characterized by their electrical recoverability. In the first or recoverable stage, leakage current after QB could be recovered to the SILC level by applying proper reverse bias. In the second or unrecoverable stage, however, no electrical recovery is observed. Conduction mechanisms at QB were also studied using carrier separation and DCIV techniques.