High thermal stability metal gate with tunable work function

Abstract

It has been reported that the work function of Ta-Pt alloys is tunable and Ta-Pt is a possible gate material for CMOS devices. In this work, we demonstrate that the Ta-Pt alloy is thermally stable up to 900degreesC. The impact of oxygen contamination and thermal stress on the stability of the MOS structure with the alloy gate is also discussed. It is concluded that the Ta-Pt alloy is a good candidate for gate electrode in the nanoscale CMOS regime and is compatible with the conventional self-aligned process.