NiPt (10 at. %) germanosilicidation of substrates with high Ge content

Abstract

In this paper, a first assessment of Ni0.9Pt0.1 germanosilicidation on Si0.2Ge0.8 is proposed. An optimized surface preparation is identified, among various options including a chemical process based on a remote plasma (i.e., the SiconiTM process) and physical processes based on direct plasmas. It enables to remove the substrate native oxide without significantly damaging the Si0.2Ge0.8 surface. The subsequent system evolution under annealing shows the development of Ni-rich phases, the nature of which being impacted by the type of surface preparation. The final layer is identified as being Ni(Pt)(Si0.2Ge0.8) and presents a bi-layer morphology when an Ar-based physical surface preparation process is used before metal deposition. This specific morphology is due to Pt segregation during solid-state reactions.