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 an nealed Ni, Ti, and Al contacts to both Si (0001) and C (0001BAR) termi nated faces of 6H-SiC are compared by using x-ray photoemission spectr oscopy, current-voltage, and capacitance-voltage data. For annealing t emperatures in the 400 to 600-degrees-C range Ni and Ti contacts have significantly more dissociation of interface SiC and formation of reac tion 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 met al/6H-SiC interface chemical reactivity