Nickel and Tantalum thin films with 3:5 thickness ratios were deposited in succession onto 4H–SiC substrate at room temperature. The samples were then heated in situ in vacuum at 650, 800 or 950°C for 30min. Glancing angle X-ray diffraction (XRD), Auger electron spectroscopy (AES) and current–voltage (I–V) technique were used for characterising the interfacial reactions and electrical properties. Amorphous Ni–Ta can be formed by solid-state reaction at 650°C. The minor dissolved Ni in the Ta metal promotes the reaction between Ta and SiC. With increasing annealing temperature up to 950°C, the dominant carbide changes from Ta 2 C to TaC and a layer structure is developed. Electrical measurements show that ohmic contact is formed after annealing at or above 800°C.