Reconstruction of the potential profile in an insulating layer using current-voltage characteristics of tunneling MIS diodes

A method for reconstruction of the potential profile in an insulating layer is developed on the basis of the field dependence of the tunneling current through the layer. The coordinates of the turning points as functions of the voltage applied to the insulating layer are determined in quasi-classical approximation from the tunneling current-voltage characteristics. The potential is constructed using these functions. The developed algorithm was applied to an n(+)-Si-SiO2-n-Si structure with oxide thickness of 37 angstrom. Typically, for a real potential profile, there exist relatively thick layers (of similar to 10 angstrom) with lowered potential that separate SiO2 from the actual tunneling barrier.