Cu contamination effect in oxynitride gate dielectrics

We have studied the effect of Cu contamination in oxynitride gate dielectri cs. Compared to thermal SiO2 with a physical thickness of 3-5 nm, the oxyni tride shows a much improved Cu contamination resistance. Furthermore, the C u contamination resistance increases with increasing nitrogen content. The mechanism of improved gate dielectric resistance to Cu is due to the strong diffusion barrier properties of oxynitride as observed by secondary ion ma ss spectroscopy. (C) 2001 The Electrochemical Society.