The effect of the post-metallization annealing of devices having HfO2, La2O3, or Y2O3 dielectrics and poly-Si or TaN gate electrodes was studied. Forming gas (10% H-2/90% N-2) annealing at 400 degreesC enhanced drive current and channel mobility of devices having 1.2 nm HfO2 gate dielectrics, by eliminating interface states. Post-metal annealing in 10% D-2 for 1.2 nm HfO2 gate dielectrics resulted in larger enhancements in drive current and device channel mobility than forming gas annealing. Similar enhancements of the device characteristics were observed in La2O3 (300 mV shift in both flatband and threshold voltage) and Y2O3 (200 mV shift only in threshold voltage) materials. Annealing in pure nitrogen was found to degrade the dielectric quality of HfO2, including a decrease in device current and 50% lower capacitance. (C) 2004 The Electrochemical Society.