FABRICATION OF 25 NM GOLD-BRIDGES AND OBSERVATION OF BALLISTIC AND QUANTUM INTERFERENCE EFFECTS

This paper is devoted to pure Au quantum wires with a length varied between 50 nm and 1-mu-m. In order to obtain extremely pure metallic nanometer structures, a liftoff process is preferred. To overcome the problem of grain size limited linewidth control and edge quality, a four-layer resist system for electron beam lithography has been developed, which enables the reproducible fabrication of mesoscopic devices with lateral dimensions down to 25 nm. I-V characteristics and magnetoconductance measurements have been carried out. Especially in the case of short wires, where electron transport is in the quasiballistic regime, universal conductance fluctuations have been observed, which are visible even at temperatures above 30 K.