A Novel Three-Dimensional Submicron ZnO Inverter Technology with Refined Contact Design

Abstract

Impact of source/drain contacts on the operation performance of three-dimensional (3-D) zinc-oxide (ZnO) logic inverters is explored in this work. The 3-D inverters consisting of a load vertically stacking on a driver were constructed with the film-profile-engineered (FPE) approach. Use of an ultrathin ZnON contact layer is proposed and demonstrated to be effective in reducing the source/drain (S/D) series resistances (RSD) of the devices. From the material characterization, the improvement in the electrical characteristics is attributed to the suppression of an insulating interfacial oxide layer present at the contact interface which may impede the carrier transport. Measurement results of inverters indicate that the voltage gain can be improved from 9.7 V/V to 13.2 V/V as the scheme is implemented.