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

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_gs stress, HEIP is found to dominate the shift of threshold voltage Vt. When V_gs increases to a moderate value, the V_t shift can be fully dominated by interface trap creation. Hole injection and trapping into the oxide occurs when V_gs is increased further to V_gs = V_ds. For the first time, the effects of interface trap creation and oxide charge trapping on the V_t shift are quantified by the proposed technique.