Fabrication and Characterization of Ohmic Contacts to 3C-SiC Layers Grown on Silicon

This paper reports on the formation and characterization of Ohmic contacts to n-type and p-type type 3C-SiC layers grown on silicon substrates. In particular, Ohmic contact behavior was obtained either using Ni or Ti/Al/Ni layers annealed at 950°C. The values of the specific contact resistance ρc estimated by means of circular TLM (C-TLM) structures varied in the range ~ 10-3-10-5 Ωcm2, depending on the doping level of the 3C-SiC layer. A structural analysis performed by X-Ray Diffraction (XRD) allowed to identify the main phases formed upon annealing, i.e., Ni2Si and Al3Ni2. The morphology of the reacted contacts depended on that of the underlying substrate. The results can be useful for the development of a variety of devices on the cubic 3C-SiC polytype.