Microstructuring of glass with excimer laser radiation at different processing gas atmospheres for microreaction technology

Microstructuring of soda lime -glass with excimer laser radiation is examined to present its process capabilities for production of surface structures particularly for microreaction technology. Material removal rates, geometries of microstructures and transmission/reflexion of processed soda lime glass are investigated for ArF excimer laser radiation (lambda(L) = 193 nm, tau(L) .= 20 ns) and KrF excimer laser radiation (lambda(L) = 248 nm, tau(L) = 25 ns). Processing of glass at atmospheric pressure down to vacuum at p= 10 mbar (He as processing gas) is carried out to investigate the correlation between processing gas pressure and generation of debris (solidification of molten material and re-deposition from expanding vapor/plasma). The influence of processing gas atmospheres consisting of He/F(2) (50/50 vol.%) with a total pressure in the vacuum chamber of 10 mbar < p< 250 mbar on height/ width of the debris is examined. Ultrasonic cleaning of glass after processing is investigated for reduction of debris. Optical microscopy, white light interferometry, optical spectroscopy and X-ray photoelectron spectroscopy (XPS) are used for analysis of microstructures and debris.