Nano-Electro-Structural Evolution of Ni-Si Ohmic Contacts to 3C-SiC

This paper reports oil 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 degrees C caused a gradual increase of the uniformity of the nanoscale current-distribution, with all accompanying reduction of the specific contact resistance from 5 x 10(-5) to 8.4 x 10(-6) Omega cm(2). After high temperature annealing (950 degrees C) the structural composition of the contacts stabilized. as only the Ni(2)Si phase was detected. A comparison with previous literature findings suggests a superior crystalline quality of the single domain VLS 3C-SiC layers.