In this paper, fluorine incorporation into the Hf O2 gate dielectrics by post C F4 plasma treatment was proposed to improve the electrical characterization. TaN-Hf O2 -p-Si capacitors were demonstrated in this work. The characteristics of fluorinated Hf O2 gate dielectrics were improved, including the capacitance-voltage hysteresis and current-voltage behaviors. This may be attributed to the fluorine incorporated into the Hf O2 gate dielectrics as revealed by secondary ion mass spectroscopy. Moreover, the formation of Hf-F bonding was observed through electron spectroscopy for chemical analysis spectra.