Fabrication of narrow comb-shaped electret by removing charge using excimer laser beam from charge-implanted CYTOP film for avoiding electrostatic repulsion problem

A new fabrication method of narrow comb-shaped electret using excimer laser abrasion is proposed in this paper. In this method, charge is firstly implanted into the whole area of unpatterned electret film; then the charge in unwanted area is removed by thermal energy of excimer laser irradiation. The electrostatic repulsion problem, which limits the minimum width of electret, is cleared by this method. The surface potential was linearly decreased with increasing excimer laser energy. The electret width is defined by interval of laser line scan. In this study, minimum electret width of 20 μm was successfully achieved.