Ge-Ni and Ge-Al-Ni systems are candidates as contact materials for GaAs. This paper offers some data about the effect of aluminium on the formation of intermetallic phases between Ge and Ni. The presence of aluminium caused a phase separation but did not prevent the reaction only a delay was observed and intermetallic compounds were always found with furnace annealing in nitrogen ambient. The phase formation depended upon the aluminium concentration in germanium. For example, 60 at.% of Al in Ge shifted the formation temperature to 600°C and NiAl and Ni5Ge3 phases were detected, in contrast to 30 at.% where this temperature was only 400°C and single Ni5Ge3 phase was obtained. In addition, the Ge-Ni phases were also produced by ion beam intermixing using Ar+ and Xe+ beams. The samples were subjected to RBS and X-ray diffraction to measure the composition and to identify the phase, respectively. An intercomparison between the compounds produced by these two techniques will be presented.
ASJC Scopus subject areas
- Nuclear and High Energy Physics