Multiple State Electrostatically Formed Nanowire Transistors

Electrostatically formed nanowire (EFN)-based transistors have been suggested in the past as gas sensing devices. These transistors are multiple gate transistors in which the source to drain conduction path is determined by the bias applied to the back gate, and two junction-side gates. If a specific bias is applied to the side gates, the conduction band electrons between them are confined to a well-defined area forming a narrow channel - the EFN. By applying a nonsymmetric bias on the side gates, the lateral position of the EFN can be controlled. We propose a novel multiple state EFN transistor (MSET) that utilizes this degree of freedom for the implementation of complete multiplexer functionality in a single device. The basic device functionality was verified through simulation of MSETs with three and four well defined conduction states. The multiplexer functionality allows a very simple implementation of binary and multiple valued logic functions.