Peter Grünberg Institut (PGI 9), Forschungszentrum Jülich GmbH, Jülich, Germany, Zentralinstitut für Engineering, Elektronik und Analytik (ZEA-3), Forschungszentrum Jülich GmbH, Jülich, Germany, University of Grenoble Alpes and CEA, LETI, MINATEC Campus, Grenoble, France, IHP, Im Technologiepark 25, Frankfurt (Oder), Germany, Brandenburgisch Technische Universität BTU, Institut für Physik, Konrad Zuse Str.1, Frankfurt (Oder), Germany

We present a comprehensive study on the formation and tuning of the Schottky barrier of NiGeSn metallic alloys on Ge1-xSnx semiconductors. First, the Ni metallization of GeSn is investigated for a wide range of Sn contents (x = 0-0.125). Structural analysis reveals the existence of different poly-crystalline NiGeSn and Ni3(GeSn)5 phases depending on the Sn content. Electrical measurements confirm a low NiGeSn sheet resistance of 12 ?/? almost independent of the Sn content. We extracted from Schottky barrier height measurements in NiGeSn/GeSn/NiGeSn metal-semiconductor-metal diodes Schottky barriers for the holes below 0.15 eV. They decrease with the Sn content, thereby confirming NiGeSn as an ideal metal alloy for p-type contacts. Dopant segregation for both p- and n-type dopants is investigated as a technique to effectively modify the Schottky barrier of NiGeSn/GeSn contacts. Secondary ion mass spectroscopy is employed to analyze dopant segregation and reveal its dependence on both the Sn content and biaxial layer strain. © 2017 Author(s).

Doping (additives), Germanium, Mass spectrometry, Metals, Nickel, Secondary ion mass spectrometry, Segregation (metallography), Semiconductor diodes, Tin, Tin alloys, Tuning, Dopant segregation, Electrical measurement, Metal-semiconductor-metal diode, Metallic alloys, Polycrystalline, Schottky barrier heights, Schottky barriers, Secondary ion mass spectroscopy, Schottky barrier diodes