Effect of ion-beam sputter damage on Schottky barrier formation in silicon

Abnormal rectifying behavior has been observed in molybdenum/silicon Schottky barrier diodes produced by ion-beam sputter deposition of Mo on single-crystal Si. Rectifying, rather than ohmic contacts are obtained on p-type Si, while ohmic behavior is seen on n-type Si. These results are contrary to the usual results reported in the literature, and are shown to be caused by ion-beam surface damage of Si. The damage does not simply cause a surface layer of high-recombination velocity, but rather tends to bend the Si band edges downwards, irrespective of the Si conductivity type.