  This paper is a report on Ohmic contacts on n-type and p-type type cubic
silicon carbide (3C-SiC) layers grown on silicon substrates. In particular, the
morphological, electrical and structural properties of annealed Ni and Ti/Al/Ni
contacts has been studied employing several characterization techniques. Ni
films annealed at 950{\deg}C form Ohmic contacts on moderately n-type doped
3C-SiC (ND ~ 1x1017cm-3), with a specific contact resistance of 3.7x10-3
{\Omega}cm2. The main phase formed upon annealing in this contact was nickel
silicide (Ni2Si), with randomly dispersed carbon in the reacted layer. In the
case of a p-type 3C-SiC with a high doping level (NA ~ 5x1019cm-3), Ti/Al/Ni
contacts were preferable to Ni ones, as they gave much lower values of the
specific contact resistance (1.8x10-5 {\Omega}cm2). Here, an Al3Ni2 layer was
formed in the uppermost part of the contact, while TiC was detected at the
interface. For this system, a temperature dependent electrical characterization
allowed to establish that the thermionic field emission rules the current
transport at the interface. All these results can be useful for the further
development of a devices technology based on the 3C-SiC polytype.
