LOW TEMPERATURE UV LASER ETCHING OF PMMA: ON THE MECHANISM OF ABLATIVE PHOTODECOMPOSITION (APD).

In order to understand the degree to which a thermal component exists in the ablation of poly(methyl methacrylate) (PMMA), we investigated the temperature dependence of APD. The study of the ablation characteristics of PMMA at 193 nm reveals no temperature dependence. Etching characteristics at 248 nm, however, show a strong temperature dependence and we conclude that a thermal component plays a key role in the etching mechanism.