Charge trapping and positive-bias temperature instability were investigated for various post-deposition annealing conditions in an HfO2 nMOSFET. Pulse-based measurements were performed in order to characterize charge trapping effects. Compared with NH3 post-deposition annealing, the NH3+O2 post-deposition annealing indicated a significant reduction of charge trap sites in HfO2; causing an improvement in device performance and reliability. A 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 HfO2nMOSFET. M.Jo, H.Park, M.Chang, H.S.Jung, J.H.Lee, H.Hwang: Microelectronic Engineering, 2007, 84[9-10], 1934-7