The use of Ni to form metal contacts to SiC has received considerable attention recently for both ohmic and Schottky contact formation. Within this paper, we present results on the formation of Ni/SiC Schottky barriers, for a variety of sample preparations which include a RCA clean, thermal oxide growth and strip and a UHV clean by thermal desorption. An XPS study was performed to examine the chemical interactions occurring at the Ni-SiC interface for sub-monolayer and increasing Ni deposition and as a function of temperature. In addition, a parallel study was performed whereby a thick (35nm) layer of Ni was deposited in-situ onto these clean surfaces and patterned into circular diodes. The diodes were then characterised electrically, using an I-V technique and a barrier height of 1.6eV with ideality, n of 1.1 was recorded. Upon annealing the diodes at 500 degreesC the barrier height was seen to increase to 1.73eV in agreement with the XPS results. The work was then extended to diodes formed under HV with no UHV clean. Barrier heights of 1.6eV with idealities of 2 were recorded for both RCA cleaned and oxide stripped samples. However, upon annealing these diodes at 500 degreesC the barrier height was increased to 1.9eV and the ideality improved to match that of the UHV formed diodes.