Polarity dependent Al–Ti contacts to 6H–SiC

In this paper, an Al–Ti contact preparation method is described on 6H–SiC wafers. The Al and Ti were both separately deposited and co-deposited onto Si ! C polarized (0 0 0 1) C and C ! Si polarized (0 0 0 1) Si faces of SiC substrate by dc magnetron sputtering. The samples were annealed at 1000 8C in N2 atmosphere. The phase and morphology of the formed contacts were investigated by transmission electron microscopy. The formed contacts clearly showed polarity dependence on SiC substrate. When the SiC substrate was Si ! C polarized the binary Al3Ti phase generated. When it was C ! Si polarized the ternary Ti3SiC2 formed along with the Al3Ti resulting in a bilayered contact structure. # 2004 Elsevier B.V. All rights reserved