Micromachining of electret materials, advantages and possibilities

A process is described for the micromachining of organic electret materials like Teflon FEP (fluorinated ethylene propylene). The authors have used photolithography and plasma etching, by which electrets can be etched selectively. The advantages of micromachining electrets in such a way are numerous. Miniature sensors like microphones and pressure sensors, containing local areas using Teflon, have been realized in the authors´ laboratories. The process can also be used for electret research. An example is the overall reduction of electret film thickness, by which the authors have determined the average penetration depth of accelerated electrons in Teflon FEP