Characterization Shottky barriers occurring at the metal-6H-SiC contact based on results of studies of current-voltage characteristics

Current-voltage characteristics of Shottky barriers occurring at the metal-6H-SiC contact were studied. 6H-SiC single crystals of n-type conductivity were grown by Lely method and by sublimation epitaxy. The Shottky diodes were prepared using various metals (Mo, Ni, Au, Al), single crystal faces ((0001)Si or (0001)C), surface treatments prior to the deposition (sublimation etch, different types of chemical treatment) and deposition regimes (crystal temperature during deposition). Forward currents were identified which had an exponential dependence on voltage: J = J0exp[qU/(nkT)]. The effect on the parameters J0 and n of the way of barrier preparation, annealing temperature and the contacting pressure during measurements is discussed.