Oxygen vacancy induced charge trapping and positive bias temperature instability in HfO2nMOSFET

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