Fast MEMS releasing with polymer and nano-graphite particle additive

This paper proposes a method of mixing polyimide with nano-graphite particle additive to increase the releasing rate of sacrificial layer for the first time. The plasma etching of polymer based sacrificial layer was performed, which shows polyimide filled with nano-graphite has a higher reaction rate than normal polyimide under the same releasing condition. The highest releasing rate of 0.55 μm/min is realized under the plasma etching condition of 100 ml/min O₂ flow rate and 500 W power for 3.5 μm thick graphite-filled polyimide layer.