The charge trapping and positive-bias temperature instability were investigated at different post-deposition annealing conditions in HfO2 nMOSFET. Pulse-based measurements (Pulsed Id-Vg and “pulse on the fly”) were performed to characterize charge trapping effect. Compared with NH3 post-deposition annealing, the NH3+O2 post-deposition annealing shows significant reduction of charge trap sites in HfO2, which causes the improvement of device performance and reliability. The significant improvement after additional annealing could be explained by the passivation of O vacancies in HfO2.

Oxygen Vacancy Induced Charge Trapping and Positive Bias Temperature Instability in HfO2 nMOSFET. M.Jo, H.Park, M.Chang, H.S.Jung, J.H.Lee, H.Hwang: Microelectronic Engineering, 2007, 84[9-10], 1934-7