New Developments in Chemical Wet Processes. Microfabrication Based on Self-assembled Monolayer Resists and Wet-chemical Processes.

Abstract

Organosilane self-assembled monolayers (SAMs) have been applied to photoresists in a photolithography using vacuum-ultraviolet (VUV) light at 172 nm in wavelength. Although SAMs consisting only of alkyl chains are not photosensitive to UV lights used in conventional photolithographies, micropatterning of such SAMs were achieved through the dissociative excitation of the organic molecules and the subsequent oxidation reaction with activated oxygen species generated by VUV irradiation of atmospheric oxygen. Since this VUV photolithography is based on the photodecomposition of carbon-carbon bonds, the method, in principle, will be applicable to any organic thin films. Furthermore, pattern transfer techniques by the use of wet processes, that is, chemical etching, electroless plating and spatially regulated growth of mesostructured silica film, have been demonstrated.