Abstract

Plasma polymerized tetrafluoroethylene (PPTFE) is shown to undergo efficient 248 nm excimer laser ablation. The principle difference between this material and the analogous polytetrafluoroethylene (PTFE), which results in only poor quality ablation, is PPTFE's much greater absorption coefficient. A plot of the ablation depth per pulse versus incident fluence indicates that the threshold for significant ablation occurs near 50 mJ/cm2, and that approximately 0.7 microns/pulse can be removed at 800 mJ/cm2. Near threshold, the ablation rate curve can be fit by a single Arrhenius- type exponential. This suggests that the removal process is governed by a photothermal process, similar to well known laser induced thermal desorption experiments. In the very low fluence regime between 10 and 30 mJ/cm2, small removal rates are measured in a process that is likely dominated by non-thermal ablation. The talk concludes with a discussion of the high quality, micron-size features that can be directly patterned into PPTFE surfaces.

© 1990 Optical Society of America