Study on direct etching of poly(tetrafluoroethylene) by high-energy heavy ion beams

•PTFE can be etched directly using MeV region high energy heavy ion beam.•The etching rates tended to increase with the atomic number (Z) of ion species.•There are thresholds of irradiation dose for the etching, depending of Z of ions.•The etching is mainly proceeded by both chain scission and decomposition from medium.•Micro-fabrication of PTFE using Ni mesh mask was succeeded with fine pattern.

Micro-fabrication of poly(tetrafluoroethylene) (PTFE) was carried out using a high-energy heavy ion beam in the MeV region. PTFE was irradiated with various ions (6 MeV/u) under vacuum (<1.0×10−4 Pa) at room temperature (298 K). The surface of the irradiated PTFE was observed by laser microscopy and a scanning electron microscope (SEM). Micro-scale fabrications of PTFE were successfully performed by direct ion beam etching. Under our experimental conditions the etching proceeded more effectively by heavy ion beams (larger than N7+), compared with lower-energy ion beams (keV region). A larger atomic number (Z) of the irradiating ion induced higher etching rates in PTFE; the etching rate for Ne10+ and Xe54+ changed from 6.5×10−13 to 2.0×10−11 μm/(ion cm−2), respectively. As a result we suggest that due to their high electronic stopping powers, etching could be efficiently achieved using high-energy ion beams.