Thermally stable fully silicided Hf-silicide metal-gate electrode

We demonstrate, for the first time, thermally stable fully silicided (FUSI) Hf-silicide gate electrode whose work function (4.2 eV) is very close to that of n⁺ polysilicon. No polysilicon depletion effect and excellent thermal stability with negligible change in equivalent oxide thickness and flatband voltage even after high-temperature annealing at 950 °C are demonstrated. These results indicate that FUSI Hf-silicide is a promising candidate for n-MOSFET metal-gate electrode for dual-metal CMOS process.