Surface microfabrication of silica glass by excimer laser irradiation of toluene solution

Laser-induced backside wet etching of silica glass plates was performed by the excitation of a pure toluene solution with a ns-pulsed KrF excimer laser at 248 nm. Well-defined grid micropattern was fabricated without debris and microcrack around the etched area. To understand the etching mechanism, the formation and propagation of shockwave and bubble were monitored by time-resolved optical microscopy at the interface between the silica glass and the toluene solution after laser irradiation. Transient high-pressure as well as high-temperature generated by UV laser irradiation plays a key role in the etching process.