This paper reports on the macro- and nanoscale electro-structural evolution, as a function of annealing temperature, of nickel-silicide Ohmic contacts to 3C-SiC, grown on 6H-SiC substrates by a Vapor-Liquid-Solid (VLS) technique. The structural and electrical characterization of the contacts, carried out by combining different techniques, showed a correlation between the annealing temperature and the electrical characteristics in both the macro- and the nanoscale measurements. Increasing the annealing temperature between 600 and 950 °C caused a gradual increase of the uniformity of the nanoscale current-distribution, with an accompanying reduction of the specific contact resistance from 5 x 10-5 to 8.4 x 10-6 Ωcm2. After high temperature annealing (950 °C) the structural composition of the contacts stabilized, as only the Ni2Si phase was detected. A comparison with previous literature findings suggests a superior crystalline quality of the single domain VLS 3C-SiC layers.
Structural and electrical characterization of AuPtAlTi Ohmic contacts to AlGaN∕GaN with varying annealing temperature and Al content
