A thin film of ruthenium was deposited on n-type-4-hexagonal-silicon- carbide (4H-SiC) so as to studythe interface behaviour of the ruthenium Schottky contact with silicon carbide. Ruthenium (Ru) Schottkydiode dots were also fabricated by deposition of ruthenium on n-type-4H-SiC which had nickel as aback ohmic contact. The Ru-4H-SiC Schottky barrier diodes (SBDs) and thin films were both annealedisochronally in a vacuum furnace at various temperatures. Rutherford-backscattering-spectrometry anal-ysis of the thin film sample showed evidence of formation of ruthenium silicide (Ru2Si3) and diffusionof ruthenium into silicon carbide at annealing temperatures of 700?C and 600?C respectively. Ramananalysis of the sample that was annealed in a vacuum at 1000?C showed evidence of the formation ofgraphite, and Ru2Si3. Despite the occurrence of the chemical reactions and diffusion of ruthenium into4H-SiC, the SBDs were operationally stable up to the final annealing temperature of 1000?C.