Submicron Patterning of Polydimethylsiloxane resists on electronic materials

Abstract

This report describes a novel technique for the fabrication of submicron-sized polydimethylsiloxane (PDMS) resist patterns on electronic material substrates using decal transfer lithography (DTL) in conjunction with reactive ion-beam etching (RIE). An O2/CF4 gas mixture is used to etch a supporting top-side PDMS thin-film in a closed-form decal to reveal conventional resist structures. These structures further provide an effective latent image that can, in turn, extend soft-lithography as a method of a form of multilayer lithography, one yielding microstructures similar to those obtained from the conventional photochemical methods used to prepare such resists. Specifically, the combined DTL/RIE patterning procedure was found to be compatible with commercially available planazation layers, and provides a direct means for preparing high aspect ratio resist features. This report further illustrates the applicability of this new form of soft-lithography for fabricating large area electronic devices, describing model silicon-based thin-film transistors fabricated using a silicon-on-insulator (SOI) wafer.