Self-developing photoetching of poly(ethylene terephthalate) films by far-ultraviolet excimer laser radiation

Radiation of 193-nm (ArF excimer laser) wavelength can cause the etching of surfaces of poly(ethylene terephthalate) (PET) films in a controlled manner without any subsequent processing. Etch rates of 1200 Å/pulse of 370 mJ/cm2 were realized in air. The reaction can be attributed to (ijk) the high absorption cross section of the films for the radiation which results in the energy being trapped in the first 2700 Å, (ii) the high efficiency for bond breaking at these photon energies, and (iii) the formation of numerous small fragment molecules which promotes their volatization. The process is observed in a vacuum but is considerably modified in the presence of air.