Ablation of polymers by focused EUV radiation from a table-top laser-produced plasma source

Abstract

We have investigated ablation of polymers with radiation of 13.5 nm wavelength, using a table-top laser produced plasma source based on solid gold as target material. A Schwarzschild objective with Mo/Si multilayer coatings was adapted to the source, generating an EUV spot of 5 µm diameter with a maximum energy density of ∼1.3 J/cm 2 . In combination with a Zirconium transmission filter, radiation of high spectral purity (2% bandwidth) can be provided on the irradiated spot. Ablation experiments were performed on PMMA, PTFE and PC. Ablation rates were determined for varying fluences using atomic force microscopy and white light interferometry. The slopes of these curves are discussed with respect to the chemical structure of the polymers. Additionally, the ablation behavior in terms of effective penetration depths, threshold fluences and incubation effects is compared to literature data for higher UV wavelength.

Surface Modification of Polymer Substrates for Biomedical Applications

“…Polymers with a higher degree of crystallinity exhibit a lower etching rate than the more amorphous ones, due to the greater structural integrity of the crystalline phase. Molecular weight and the orientation of the polymer chains also play a role in the rate of etching [68]. The etching rate and the changes in morphology caused by plasma treatment are naturally dependent not only on the duration of the treatment, but also on the power used [69].…”

High-efficiency laser fabrication of drag reducing riblet surfaces on pre-heated Teflon

“…PTFE has numerous applications [34] due to its unique properties among polymers: extremely low friction coefficient [35,36]; high hydrophobicity [37]; exceptionally high melting point and thermal decomposition temperature [38]; low thermal conductivity [39]; resistance to aggressive chemicals [40]; particularly low specific electrical conductance [41]. However, PTFE is transparent in a wide spectral a range of visible light [42] and has large laser ablation threshold even for ultrashort ultraviolet irradiation [43][44][45][46][47][48]. Thus, laser machining of Teflon is not always a straightforward process.…”

Super hydrophobic surface of polytetrafluoroethylene fabricated by picosecond laser and phenomenon of total internal reflection underwater

“…Various phenomena, such as snow sticking, contamination, oxidation, and current conduction are expected to be inhibited on such a surface. The investigation on hydrophobic properties of Polytetrafluoroethylene (PTFE) thin films has been reported [8][9][10]. The wettability of solid surfaces, governed by both the chemical composition and the geometrical microstructure of the surface, is a very important property.…”