Improved reliability characteristics of ultrathin high-k MOSFET with TiN gate by employing two step post deposition annealing process

Hafnium and hafnium based oxide materials seems most promising gate material for aggressively scaled device. However, the mobility degradation of Hf-base gate dielectric is one of the most difficult problems. Recently, we have reported a significant improvement in interface characteristics, device drive current and maximum transconductance (Gm) by employing high pressure (HP) deuterium annealing at relatively low temperature. However reliability characteristics are not much improved compared with forming gas annealed sample. This might be due to the presence of excess deuterium in the oxide. In this presentation, we report the effect of two step anneal process and its effect on reliability and performance