Submicrometer polymer transistors fabricated by a mask-free photolithographic self-alignment process

Abstract

A simple method for patterning down to 400 nm gaps between two thin-film electrodes is presented. The edge of the first electrode defines the gap via a photolithographic step using off-normal through-substrate exposure. It is demonstrated that the gap width can be controlled simply by adjusting the exposure angle and/or photoresist thickness. Using this process, poly(3-hexylthiophene) field-effect transistors with a submicrometer channel and a large channel width to length ratio of up to 5000 have been fabricated. Since the process is mask free, contactless, highly parallel, and offers high resolution, it is potentially suited for the high-throughput, low-cost fabrication of electronic circuits. © 2008 American Institute of Physics.