Tunneling in a metal-semiconductor-semiconductor thin-film diode

Abstract

By incorporation of a thin layer of near intrinsic semiconductor, one can change a metal-semiconductor ohmic contact into a retifying junction. This concept is demonstrated by inserting an amorphous silicon film of less than 40 A between aluminum and silicon. The resulting diode's forward current is found to be controlled by majority carrier tunneling, and its reverse current is governed by minority carrier diffusion. From experimental data of I-V and C-V measurements, we find a flat-band condition at zero bias and deduce a tunneling barrier height of 0.67 eV at room temperature. The energy band diagram is presented to illustrate the operation principle of the tunnel diode. © 1986.