UV annealing of inorganic-organic composite films prepared by sol-gel technique

SiO2/MC (Methylcellulose) composite materials formed by the sol-gel technique were investigated for optical applications. MC was used as an organic binder to yet a thicker film by a single spin-coating process. After spin-coating and placement in air, a uniform single coating layer with a thickness of approximately 900 nm was obtained. The films were annealed in 0.2 bar O-2 ambiance under the irradiation of 222 nm excimer UV (ultraviolet) lamps at temperatures from room temperature to 300 degreesC. The film properties were studied by scanning, electron microscopy, thermal gravimetric analysis, Fourier-transform infrared spectroscopy, UV-VIS spectrophotometry, and X-ray photoelectron spectroscopy. Absorption feature approximately 2900 cm(-1) in FTIR spectra, corresponding to some organic compounds, was found to disappear after UV annealing at low temperatures, indicating active oxygen species produced by UV light can enhance the removal of the organic compounds in the films. This UV annealing technique can be applicable to other optical and electrical materials. (C) 2003 Elsevier B.V. All rights reserved.