Characterization of temperature dependence for HfO2 gate dielectrics treated in NH3 plasma

Abstract

For the first time, the characteristics and temperature dependence of electrical properties for ultrathin HfO2 gate dielectrics treated in NH3 plasma after deposition were investigated. After this treatment, significant nitrogen incorporation at the HfO2/silicon interface (interfacial layer) was examined by Auger electron spectroscopy. Moreover, the formation of Hf-N bonding and the suppression of Hf-Si bonding were observed from electron spectroscopy for chemical analysis spectra. The activation energy of charge trapping reflected in the current-voltage characteristics was effectively reduced, which led to improved hysteresis and its weaker temperature dependence in HfO2 gate dielectrics treated in NH3 plasma. (C) 2003 The Electrochemical Society.