Abstract: A method and apparatus for determining the thickness of an interfacial oxide film intermediate to a polysilicon layer of a first conductivity type and a silicon substrate of a second conductivity type supporting a p-n junction. Radiant energy, preferably in the form of light, is directed on to the top surface of the polysilicon layer thereby stimulating carriers which concentrate at the interfacial oxide film, allowing the excited carriers to diffuse across the oxide film, and creating a short circuit, the magnitude of which is inversely related to the thickness of the interfacial oxide film.

Abstract: A non-volatile semiconductor memory and switching device employing a Schottky barrier junction and a dual layered dielectric system for entrapping charges adjacent thereto. The dual layered dielectric system typically comprises a layer of nitride on a layer of oxide arranged such that trapped charges within the oxide and at the nitride-oxide interface act to alter the depletion region beneath, and in the vicinity of, the Schottky contact. Trapped charges may be made to selectively modify the Schottky barrier depletion region and vary its conductivity characteristics between a diode characteristic (OFF) at one extreme and ohmic contact (ON) at the other, all in accordance with the magnitude and sign of the trapped charges.