Microetching of fused silica by laser ablation of organic solution with XeCl excimer laser

By a laser-induced backside wet etching method using a pyrene/acetone solution, a fused silica plate was etched upon irradiation with a conventional XeCl excimer laser. The etch rate was about 50% lower than that obtained with a KrF excimer laser under the same experimental conditions. The threshold fluence for etching was estimated to be below 0.5 J cm−2 and a typical etch rate was around 10 nm pulse−1 at a fluence of 1 J cm−2. After producing the sample having the 10 μm lines and space by irradiation with the first 200 pulses, the second 400 pulses were irradiated to the target sample rotated at right angle. As a result, a square dotted pattern was given without damages for the first etched pattern. Micrographs of the etched surfaces show that this process is a remarkably gentle process free from crack and debris, and favorable for microcrack-free etching of transparent materials.