Hot Carrier Degradation Mechanism Under Pulsed Stress in Mosfets

Reduction of hot carrier degradation in MOS devices has been one of the most serious concerns for MOS-ULSIs. It will be unrealistic to insure DC stress lifetime when devices are miniaturized into the deep sub-micron region and consequently the investigation of AC hot carrier phenomena corresponding to actual circuit operation is quite important. In spite of much work on AC hot carrier effect [1-3], a commonly accepted explanation has not yet been proposed. In this paper, AC hot carrier degradation mechanisms as they relate to (1) drain structure, (2) AC stress conditions, (3) frequency of AC pulse and (4) gate current, will be systematically investigated.