Effects of denuded zone of Si(111) surface on current conduction and charge trapping of HfOxNy gate dielectric in metal-oxide-semiconductor devices

This work investigated the effects of interstitial oxygen [O-i] defects at the Si(111) surface on current conduction and charge trapping of metal-oxide-simiconductor devices with HfOxNy gate dielectric. Smaller gate leakage current, stress-induced leakage current (SILC) and defect generation rate, attributable to the decrease of [O-i] defect concentration at the HfOxNy/Si interface, were observed for devices with denuded zone. The current-conduction mechanism of the HfOxNy films at the low- and high-electrical field was dominated by the Schottky and Frenkel-Poole emissions, respectively. The trapped charges in HfOxNy dielectric were positive. The mechanism related to the SILC at low-electrical field can be explained using the interface trap-assisted tunneling. (C) 2004 American Institute of Physics.