Polarity dependent reliability of advanced MOSFET using MOCVD nitrided Hf-silicate high-k gate dielectric

We report reliability of MOSFETs with MOCVD nitrided Hf-silicate (HfSiON) high-k gate dielectric. HfSiON has shown superior electrical characteristics, such as low leakage relative to SiO₂ and high mobility compared to other high-k gate dielectrics. SILC is found to be comparable to SiO₂ and better than Hf-silicate without nitridation. TDDB and BTI reveal significant difference between inversion and accumulation mode. Polarity-dependent charge trapping and defect generation are observed and attributed to asymmetric band diagram as well as dissimilar charging processes in two stress modes. Trap-assisted tunneling is evidenced by its strong temperature dependence. Charge pumping tests indicate higher interface density compared to SiO₂/Si. The Weibull slope is determined to be about 3, showing robust wear-out quality of the high-k dielectric.