A proper lifetime-prediction method of PMOSFET with 1.1 nm gate dielectrics in the lower testing voltage region

A prediction method of time dependent dielectric breakdown (TDDB) lifetime on P-type metal-oxide-semiconductor field effect transistors (PMOSFETs) with 1.1 nm gate dielectrics is studied. Prediction of a voltage dependence of TDDB lifetime was newly proposed using a defect generation probability (P/sub G/), which incorporates both scattering rate of hole and valence band electrons. It is found that the lifetime predicted with P/sub G/ is about ten times longer than that with only high testing voltage. This is the reason why both the channel hole and valence band tunneling electron (VBE) influence this probability, especially VBE is rapidly decreased with a low testing voltage below -1.5 V. Our model based on the newly proposed PG enables us to estimate the proper TDDB lifetime of PMOSFETs, and predicts a power-law voltage dependence on inversion mode.