The distortion of the interface-state spectrum due to nonequilibrium occupancy of the interface states at the metal-semiconductor interface

Using the Shockley–Read–Hall statistics and considering the charge exchanges between metal and interface states, the effects of nonequilibrium occupancy on the interface‐state spectrum measured from a forward‐biased Schottky barrier diode have been studied, both theoretically and experimentally. It is shown that due to the rapid interaction between the interface states and the minority‐carrier reservoirs at the interface, the energy density of the interface states experimentally measured can exceed that of the actual one when the constant‐temperature Schottky capacitance spectroscopy and current‐voltage methods are used. Moreover, taking the applied voltage drop across the interfacial (dipole) layer into consideration, the apparent interface‐state spectra in the vicinity of the thermal equilibrium Fermi level for various metal‐ and metal‐silicide‐Si Schottky barrier contacts can be well interpreted by a simplified interface state occupation function model, which is physically consistent with the nonideal ...