Preparation Of SiO₂-based Waveguide Films And Their Fine-patterning

This paper studied on the preparation of the SiO2-based waveguide films by sol-gel process in order to improve the film thickness. DCCA (drying control chemical additive) was added into sols, the SiO2 waveguide films were prepared; To obtain the thicker films, MAPTMS (methacryloxypropyl trimethoxysilane) and Al(O-sec -Bu)a (Aluminum sec-Butoxide) were used as precursors, chemically modified by BzAcH (l-Phenyll-3 -butanedione), the organic-inorganic composite SiO2/Al2C>3 waveguide films were obtained ; Then the fine-pattern of the thicker film and the grating were fabricated using laser interference or UV-irradiation. The absorbance and transmittance spectras were measured by UV-VIS spectre-photometer, by which the photosensitivity of the gel film was analyzed. The refractive index of films and its change with the UV light irradiation or heat-treatment were analyzed. Finally, the film thickness was measured by surface profiler, the FT-IR spectras of the films and the sols were determined by infrared spectrophotometer. The results show that:Each kind of DCCA, to have been studied on, can help to increase the film thickness, the effect of (CiHO^ is best, using it as DCCA the thickness of the single-layer SiO2 film is about 1.2 u m after heat-treatment at 500癈.The thickness of the SiO2/Al2O3 film is up to 4.5 u m after heat-treatment at 200癈. Its gel film has the absorption band at around 325nm. So when the gel film was irradiated by the corresponding UV light, the absorption band at 325nm decreases continuously with increasing irradiation time, at the same time, the solubility of the gel film declines in organic solvent, the film shows the good photosensitivity. Due to the good photosensitivity of the gel film , the fine-pattern and the waveguide were obtained. Then when the gel film was irradiated by bi-beam interference, the grating was prepared with the period of around lum.