The Etched Capacity for Sol-Gel Derived Silica-Titania Composited Films

Titania-silica thin films were prepared by a Sol-gel method. The etched ability of the thinfilms in dilute HF solution was studied. The film heat-treated at 800℃, reduced etch rate by afaCtor of almost 1000 compared with that of the film heat-treated at 200℃. The large differencebetween the etch rates of densified and undensified films can be used to produce channel waveguidestructures by laser scanning on the films. The difference of the etch rates can be explained by XRDand FT-IR spectrum, and micro Raman spectrum reveals that the crystallization in the region oflaser scanning has a normal distribution.