Evidence of tunnel-assisted transport in nondegenerate MOS and semiconductor-oxide-semiconductor diodes at room temperature

Metal-oxide-semiconductor diodes have been fabricated on p-type Wacker polycrystalline silicon with aluminum barrier metal, and semiconductor-oxide- semiconductor diodes have been fabricated by chemical spraying of indium-tin oxide on n-type single-crystal silicon. The current-voltage and capacitance-voltage characteristics of these diodes have been measured at various values of temperature above 300 K and analyzed. The results indicate the likelihood of the primary transport mechanism's being multistep tunneling instead of thermionic emission or minority carrier injection. The study also stresses the importance of investigating the temperature dependence of electrical characteristics before any firm conclusions may be drawn about the conduction mechanisms in semiconductor junctions.