Novel device lifetime behavior and hot-carrier degradation mechanisms under V/sub GS//spl ap/V/sub TH/ stress for thin-film SOI nMOSFETs

The thin-film SOI (TFSOI) MOSFET is found to have the worst device lifetime projection for a gate voltage condition of V/sub GS//spl ap/V/sub TH/ and a drain voltage below the breakdown voltage. A detailed study of the hot-carrier degradation as a function of the drain stress for this gate condition shows evidence of a transforming hot-carrier behavior and mechanism. New understanding of the dominating hot-carrier mechanisms in TFSOI MOSFETs stressed under V/sub GS//spl ap/V/sub TH/ is reported. A model of these mechanisms accounting for the observed degradation behaviors is proposed.