Self-Aligned NiGeSi Contacts on Gallium Arsenide for III-V MOSFETs

Abstract

We developed a Nickel Germanide (NiGe) based self-aligned contact technology for GaAs n-MOSFETs. The self-aligned contact metallization process is salicide-like and is compatible with III-V materials and processes. It comprises selective epitaxy of Germanium-Silicon (GeSi) on n+ doped GaAs region and a two-step metallization process for forming Nickel-Germanosilicide (NiGeSi) contacts on GaAs. With precise control of the metallization process, NiGeSi contacts on GaAs were fabricated with good ohmic behavior. Contact with smaller contact resistance RC was achieved by optimizing the metallization process. The self-aligned NiGeSi contacts were integrated in GaAs n-MOSFETs which show good output characteristics.