ELECTRICAL CHARACTERIZATION OF METAL THIN OXIDE SILICON TUNNEL-DIODESPREPARED BY RAPID THERMAL ANNEALING

We present electrical results of metal-thin oxide-silicon tunnel diode s fabricated on rapid thermal anneal (RTA) silicon wafers with native oxide layers. The annealing temperature is crucial in deciding whether a Schottky or a tunnel diode is obtained as a result of RTA. In the r everse bias direction, the degree oi inversion at tile silicon surface was found to depend on the illumination intensity and this has a dire ct effect on the magnitude of the tunnel current. Devices with gold an d aluminium top contacts resulted in minority and majority carrier tun nel diodes, respectively. The capacitance versus voltage measurements confirmed tile results obtained from the current versus voltage and X- ray photoelectron experiments. The interface trap and the fixed charge densities of our devices reduced as the annealing; temperature or ann ealing time increased.