Self-aligned, insulating-layer structure for integrated fabrication of organic self-assembled multilayer electronic devices

We demonstrate an approach for fabricating nanometer-scale devices with minimal device areas while still retaining compatibility with integrated metal wiring. A self-aligned layer of silicon oxide evaporated on top of a thin (25 nm) gold film deposited on a substrate with an etched step ensures that only a fraction of the gold, along the step edge, is exposed. Self-assembled multilayers of 11-mercaptoundecanoic acid (MUA) were grown on the exposed gold to define an arbitrarily long device length. A second, evaporated gold layer served as second electrode. Devices with between 3 and 7 MUA layers were insulating, with currents that decreased exponentially with the number of MUA layers.