Effect of adding an insulator between metal and semiconductor layers on contact resistance

Abstract

The authors investigated the effective Schottky barrier heights of metal and silicon contacts after insertion of insulator layers with different conduction band offsets. A decrease in Schottky barrier height after insertion of an insulator layer was observed. In particular, the Schottky barrier height of metal/semiconductor contacts was lowest when a ZnO layer was inserted compared to the other insulator layer types, because the conduction band offset between ZnO and silicon was the lowest among those measured. The authors also investigated current density as a function of the thickness of the insulator and doping concentration of silicon.