Abstract: A 2 J/20 Hz XeCl (308 nm) excimer laser with a flat intensity distribution is used for processing Al$-2$/O$-3$/, Si$-3$/N$-4$/, SiC and AlN ceramics and short glass fiber reinforced polymers. In order to get reproducible results, an excimer laser material processing system is built up, including a variable optical system, diagnostics, and a high-precision xy- translation stage. With this system, modifications of the surfaces at low-energy densities and the production of submillimeter structures at higher energy densities are investigated. Monitoring of important process and beam parameters with a diagnostic system is essential to get reproducible results. A CCD-camera system is used to measure the uniformity of the intensity distribution of the laser beam. The aim of the investigations is to find some correlation between beam and processing quality. Due to the low penetration depth of the laser beam into the material and rapid evaporation, only thin layers below the workpiece surface are affected, and the extension of the heat-affected zones remains extremely small. The treatment of larger areas of the materials at lower energy densities results in modifications of the surface topography. Uniform and reproducible changes of ceramics surfaces are obtained with optimized process parameters. Various mask geometries are imaged onto the surface of the material by a projection technique to produce submillimeter structures. The sharpness of the image on the workpiece surface proves to be an important parameter for producing reproducible and small structures. Larger areas are machined with the help of the xy-table. The processing quality is characterized using profilometry and scanning electron microscopy.!
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