We investigated Ni1- xPtxSi (x = 0.05-0.33) as a metal gate electrode for p-metal oxide semiconductor field effect transistors (MOSFETs). Our results showed that, with a proper atomic composition of Ni1- xPtxSi, the work function of the gate electrode can be tuned from similar to 4.59 eV (for NiSi) to similar to 5.21 eV (for Ni0.67Pt0.33Si). Negligible variations in both the extracted flatband voltages and gate oxide thicknesses with processing temperature (up to 900 degrees C) demonstrated the excellent thermal stability of the Ni0.67Pt0.33Si-SiO2 gate stacks. High-resolution transmission electron microscopy also showed no evidence of degradation at the Ni0.67Pt0.33Si-SiO2 interface and the formation Ni and/or Pt precipitates at/or beneath the SiO2-Si interface. (c) 2005 The Electrochemical Society. All rights reserved.