The use of a silicon interlayer pre-treatment to produce nickel Ohmic contacts to n-type 4H-SiC is reported. The different effects produced by RCA cleaning and a silicon interlayer pretreatment (SIP) of the SiC surface prior to Ni deposition, are discussed. Electrical characterisation of each contact using circular transmission line measurements (CTLM) was conducted. These results revealed that the contact to the RCA cleaned sample was Schottky in nature, unless annealed at temperatures greater than 700degreesC. In contrast, the SIP contact exhibited Ohmic behaviour directly after fabrication, without the need of post metallisation annealing. Contact resistances as low as 1.3E-05 were recorded for the SIP sample. Such a process has distinct technological advantages as compared to standard techniques to form Ohmic contacts to SiC. To consolidate our findings, the chemical and electrical nature of the SIP nickel-SiC interface as it was sequentially formed, and annealed, was examined using X-ray photoelectron spectroscopy (XPS). Based on these results, a model is proposed to explain the surprising as-deposited Ohmic contact nature of the SIP sample.