Direct photoetching of polymers using radiation of high energy density from a table-top extreme ultraviolet plasma source

Abstract

Articles you may be interested inDamage of multilayer optics with varying capping layers induced by focused extreme ultraviolet beam Direct photo-etching of poly(methyl methacrylate) using focused extreme ultraviolet radiation from a table-top laser-induced plasma source Formation and direct writing of color centers in LiF using a laser-induced extreme ultraviolet plasma in combination with a Schwarzschild objective Rev. Sci. Instrum.

Radiation characteristics of extreme UV and soft X-ray sources

“…Thus, with solids, the largest number of photons originating per volume can be achieved. Respective target materials are deposited on rotating cylinders [39] or quickly moving tapes [40] which provide repetition rates of up to 1 kHz. Prominent elements are gold or tin for the production of radiation at a wavelength of 13.5 nm which is applied in EUV lithography [41].…”

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

“…In order to complete and extend the results of previous publications [26,28], polymethyl methacrylate (PMMA), polytetrafluoroethylen (PTFE) and polycarbonate (PC) were used for ablation experiments. In Fig.…”

“…1) [21][22][23]. EUV radiation is generated by focusing a Nd:YAG laser (Innolas, wavelength 1064 nm, maximum pulse energy 700 mJ, pulse duration 8.8 ns) onto gaseous or solid targets [26,28]. For small EUV plasmas with high brilliance, a solid Au target (200 µm thick Au foil fixed on a copper rod) is used, yielding a plasma diameter of ∼50 µm (FWHM).…”

“…The plasma diameter was measured by direct photo-etching of PMMA at low fluences (below 500 mJ/cm 2 ). Here, the depth per pulse is linear to the incident EUV energy density [26]. Hence, the intensity distribution in the focus of the Schwarzschild objective is proportional to the depth profile of the ablation crater and can be easily determined from Using a spherical laser focus on the gold target, EUV energy density saturates at 0.73 J/cm 2 due to overheating of the plasma by the incoming laser energy.…”

Laser-plasma extreme ultraviolet and soft X-ray sources based on a double stream gas puff target: interaction of the radiation pulses with matter

“…This way a polymer layer with the thickness of the order of tens nanometers can be released by a single EUV pulse. The process is regarded as a non−thermal abla− tion and was utilized for micromachining of polymers in series of experiments using synchrotron radiation [20][21][22], LPP EUV sources [23][24][25][26][27][28][29] and EUV lasers [30]. First attempts of polymer micromachining initiated by author of the paper were performed using low energy LPP EUV source without any focusing optics [23].…”