Separation of hot-carrier-induced interface trap creation and oxide charge trapping in PMOSFETs studied by hydrogen/deuterium isotope effect

Abstract

By using the hydrogen/deuterium isotope effect, we propose a new technique to separate and quantify the effects of hot-carrier-induced interface trap creation and oxide charge trapping on the degradation in PMOSFETs. In addition to the well-known hot-electron-induced-punchthrough (HEIP) mechanism, we find that two additional mechanisms, namely, interface trap creation and hole trapping in the oxide, also play important roles in PMOSFET degradation. The degradation mechanisms are highly dependent on stress conditions. For low gate voltage V/sub gs/ stress, HEIP is found to dominate the shift of threshold voltage V/sub t/. When V/sub gs/ increases to a moderate value, the V/sub t/ shift can be fully dominated by interface trap creation. Hole injection and trapping into the oxide occurs when V/sub gs/ is increased further to V/sub gs/=V/sub ds/. For the first time, the effects of interface trap creation and oxide charge trapping on the V/sub t/ shift are quantified by the proposed technique.