Patterning of inorganic electrets

A yearlong experiment has been conducted to prove that the field emission and atmospheric ions are responsible for discharging of an electret at its edge. Based on the obtained results, a technology for patterning electret layers has been developed for technical applications. It allows fabrication of electret film structures with a feature size of 20 μm and probably less. Patterned inorganic electret lines fabricated using photolithography show no dependence of charge stability on line width based on monitoring the charge retention during one year. A general approach to electret patterning is discussed.