Contact Properties of Metal-Silicon Schottky Barriers

Abstract

Barrier heights of Schottky diodes prepared by vacuum depositions of metals onto chemically etched silicon surfaces were investigated by measuring the current-voltage and capacitance-voltage characteristics. The barrier height varied remarkably with the work function of metal and the sum of the barrier heights measured on n-type and p-type silicon was nearly equal to the energy gap of silicon. The results were well explained by applying the theory of Cowley and Sze, leading to the conclusion that the Fermi level is not always pinned at the semiconductor surface.