Abstract
The electrical reliability of gate oxynitride in metal-oxide-Si (MOS) capacitor can be clearly improved by the two-step N 2 O nitridation. The nitridation with a low temperature and a short time could form a nitrogen pileup at the poly-Si/SiO 2 interface. It is experimentally found that the charge-to-breakdown is significantly increased and the hot-electron-induced flatband voltage shift is clearly reduced. The boron penetration effects for the pMOS devices are also suppressed. The reliability improvement can be explained by the reduction of detrimental species diffused from the poly-Si, which is achieved by nitrogen pileup at the poly-Si/SiO 2 interface. This approach would be useful for the improvement of electrical properties in the ultrathin gate oxynitrides.