On the Tunneling Current through Thin Aluminum-Oxide Films

Abstract

The mechanism of the electrical conduction in a metal-insulator-metal thin film diode is discussed by the tunneling process. Experimental current-voltage characteristic and its temperature dependence of an Al-Al oxide-Al diode agree well with a theoretical calculation when the potential barrier is assumed to have a geometrically simple shape. Practical barrier height of the diode is estimated at 2.2 eV from a photosensitive measurement. Electrode effects are also discussed from the viewpoint of rectification. The surface potential of the insulator on Al film is measured to be 3.6 eV, which is consistent with a simple potential diagram of the metal and insulator surfaces.