Fermi Level Position at Semiconductor Surfaces

Abstract

There have been several recent reports of barrier height studies on metal-semiconductor interfaces. Metals of widely different work functions evaporated onto Si and GaAs surfaces indicated that in each case the energy difference
\nbetween the semiconductor conduction band edge
\nand Fermi level at the interface,φ_(Bn), was essentially
\nindependent of the metal, which indicates
\nthat the Fermi level is fixed by surface
\nstates. In the present work barrier height measurements
\nhave been made on a number of zinc-blende semiconductors to determine (a) if the barriers are in all cases determined by surface states, and (b) the relation between the Fermi
\nenergy at the interface and the band gap E_g.