Morphological and ablation characteristics of brass and fused silica after interaction with ArF excimer laser

Abstract

This study investigates the interaction of the 193 nm ArF excimer laser with brass and fused silica in the ambient air. The study compares the differences in surface morphology and ablation rate of craters produced in brass and fused silica at different values of fluence and number of laser pulses using optical and scanning electron microscopy. The ablation rate was found to be slightly lower in fused silica than in brass. The ablation rate increased from 180 to 370 nm/pulse in brass and from 120 to 240 nm/pulse in fused silica when increasing the fluence from 6.8 to 15.2 J/cm2. In contrast to fused silica, melting and ejection of molten material were dominant in the ablation of brass. Various shapes and sizes of particles were observed in the debris deposited around the craters created in brass and fused silica. Resolidified particles with sizes greater than 1 µm were observed at and around the crater edges in brass due to the deposition of the ejected liquid droplets. In fused silica, large cauliflower-like particles were observed around the craters. Nano-size particles were also formed in brass and fused silica at low fluence but with a density smaller than that of the large particles formed at high fluence. The threshold fluence calculated from the relationship between ablation rate and fluence was found to be 0.78 and 3.03 J/cm2 in brass and fused silica, respectively.