Photoreactivity of Alkylsilane Self-Assembled Monolayers on Silicon Surfaces and Its Application to Preparing Micropatterned Ternary Monolayers

The photoreactivity of an n -octadecyltrimethoxysilane self-assembled monolayer (ODS-SAM) on a Si substrate was investigated under the irradiation of vacuum ultraviolet (VUV) light of 172 nm in wavelength. The results of water contact angle, film thickness, and X-ray photoelectron spectroscopy analysis showed that the ODS-SAM decomposed gradually due to the VUV light exposure. Oxidized products, that is, −COOH groups, had formed before the ODS-SAM was completely decomposed and removed from the substrate. Coplanar ternary organosilane SAM microstructures have been successfully fabricated by employing the reaction between −OCH 3 functional groups with −COOH groups on the VUV-modified ODS-SAM.