High-k gated metal-oxide-semiconductor devices with SiGe channel and nitridation treatment using plasma immersion ion implantation (Pill) were studied in this work. After metal gate deposited, PIII nitridation treatment was performed at an energy of 2.5 key for 10 min. Experimental results show that the electrical characteristics of high-k dielectric can be obviously improved by PIII nitridation. For instance, the values of stress-induced leakage are reduced more than 50% and the value of stress-induced flat-band voltage shifts are reduced more than 33%. The equivalent oxide thickness (EOT) value of MOS device with 30% Ge content in SiGe channel and PIII nitridation can be reduced to 9.6 angstrom. (C) 2010 Elsevier Ltd. All rights reserved.