EXCIMER LASER-INDUCED ABLATION OF POLYETHERETHERKETONE, POLYIMIDE, AND POLYTETRAFLUOROETHYLENE

New experimental data on the photoablation rate of polyetheretherketone and Kapton film by 25 ns pulses of XeCl laser radiation are presented. The fluences used were in the range of 5-70 J/cm2. The etching rate increases with fluence up to about 50 J/cm2 and then saturates for both the polymers. The data can be described very well by the model proposed earlier by Srinivasan, Smrtic, and Babu (SSB), which includes both thermal and photochemical contributions to polymer ablation. This model is compared with that of Sauerbrey and Petit for describing the etch rate of polyimide with 308 nm laser pulses of various durations. It is also shown that the polytetrafluoroethylene ablation rate data of Kuper and Stuke obtained with 300 fs 248 nm laser pulses can also be described by the SSB model by modifying it to include the effects of nonlinear absorption.