13 March 2018 Resist-polymer ablation by mid-infrared-free-electron laser
Author Affiliations +
Laser ablation of poly(4-hydroxystyrene) (PHOST) film was studied using mid-Infrared free-electron laser (mid-IR FEL), of which irradiation wavelength was tuned to the vibrational absorption peaks of PHOST in mid-IR spectral region. A PHOST film was ablated by mid-IR FEL light to produce a clear hole in a PHOST film which suggested the photochemical ablation. As the threshold energy for silicon ablation was larger than that of PHOST, it was possible to ablate a PHOST film without any damage to a silicon substrate. The ablation threshold-energy ratio for PHOST to silicon was less than 0.2 and depended on the mid-FEL wavelength. The ablation threshold for a PHOST film depended also on the film thickness. The highly efficient ablation by mid-IR FEL was found to be due to the vibrational excitations of C-O stretching and C-O-H bending of PHOST.
Conference Presentation
© (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Minoru Toriumi, Minoru Toriumi, Takayasu Kawasaki, Takayasu Kawasaki, Mitsunori Araki, Mitsunori Araki, Takayuki Imai, Takayuki Imai, Koichi Tsukiyama, Koichi Tsukiyama, "Resist-polymer ablation by mid-infrared-free-electron laser", Proc. SPIE 10586, Advances in Patterning Materials and Processes XXXV, 1058613 (13 March 2018); doi: 10.1117/12.2297163; https://doi.org/10.1117/12.2297163

Back to Top