Electrical characterization of air-bridge-structured silicon wires fabricated by micromachining of silicon-on-insulator substrate

We have fabricated air-bridge-structured silicon wires by micromachining based on photolithography of an SOI substrate. The present devices have a 3D-tapered wire structure towards the center and were bridged in the air between two Si pads. The typical dimensions of the wires are 20-100 nm in width and about 30-100 nm in thickness. In this work, we characterized the electrical (I-V) properties of the wires in both vacuum and atmospheric ambient. The I-V characteristics exhibited a negative differential conductance and hysteresis at room temperature.