A new self-aligned contact technology for III-V MOSFETs

We report the first demonstration of a self-aligned contact technology for III-V MOSFETs. A novel epitaxy process with in-situ surface treatment was developed to selectively form a thin continuous germanium-silicon (GeSi) layer on gallium arsenide (GaAs) source and drain (S/D) regions. By precisely and fully converting the GeSi layer into NiGeSi, while diffusing Ge and Si into GaAs to form heavily n⁺ doped regions, a novel self-aligned nickel germanosilicide (NiGeSi) ohmic contact was achieved. This is expected to significantly enhance the performance of III-V MOSFETs.