High-Performance HfO[sub 2] Gate Dielectrics Fluorinated by Postdeposition CF[sub 4] Plasma Treatment

The superior characteristics of fluorinated gate dielectrics were investigated. Fluorine was incorporated into thin film by postdeposition plasma treatment to form fluorinated gate dielectrics. Secondary-ion mass spectroscopy results showed that there was a significant incorporation of fluorine atoms at the and interface. Improvement of the gate leakage current, breakdown voltage, capacitance-voltage hysteresis, and charge trapping characteristics was observed in the fluorinated gate dielectrics, with no increase of interfacial layer thickness. A physical model is presented to explain the improvement of hysteresis and the elimination of charge trapping. These results indicate that the fluorinated gate dielectrics appear to be useful technology for future ultrathin gate dielectrics.