Schottky barrier height and interface chemistry of annealed metal contacts to alpha 6H-SiC : crystal face dependence

The electrical properties and interface chemistry of unannealed and annealed Ni, Ti, and Al contacts to both Si (0001) and C (0001̄) terminated faces of 6H-SiC are compared by using x-ray photoemission spectroscopy, current-voltage, and capacitance-voltage data. For annealing temperatures in the 400 to 600 °C range Ni and Ti contacts have significantly more dissociation of interface SiC and formation of reaction products for the C-face than the Si-face. The chemical reactivity of the Al contact was limited and equal for both faces. Stability of the Schottky barrier height with annealing, which has a wide variation according to metal and face, is not correlated with the degree of metal/6H-SiC interface chemical reactivity