Lithographic micropatterning on the β‐PVDF film using reactive ion etching aim for high‐resolution skin sensors

We report a method for high‐fidelity lithographic patterning of the flexible β‐phase polyvinylidene difluoride (PVDF) film using traditional cleanroom equipment and commercially available materials. In our process, the chemically reactive gas of CHF 3 , CF 4 and SF 6 was used as a simple substance mixed with O 2 . The effects of process parameters on the PVDF dry etching characteristics were investigated by controlling that of Radio frequency (RF) power, process pressure, gas type and the mixed concentration in O 2 as well as its mass flow rate. At a constant RF power (100 W) and associated process conditions, 40–70 µm of fine‐line patterns and several tens µm/h of high etch rate could be realized on a 110 µm‐thick β‐PVDF film without much loss of its piezoelectricity. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.