X-ray photoelectron spectroscopy of KrF laser-irradiated polycarbonate films

Spun films of polycarbonate were photoablated in air at 248 nm. The etch and incubation data have a superlinear dependence on the laser fluence. The surface compositional changes were analysed by X-ray photoelectron spectroscopy (XPS). As evidenced by the decrease of the O/C ratio, photoablation is inferred as distinct from the low-intensity photooxidative degradation. A direct correlation is observed between the XPS and incubation data and the ablation seems to occur by chain scission at the CO bond, the fully incubated surface being an average of monomeric composition.