Dry release of MEMS structures using reactive Ion etching technique

Paper presents a dry release method for beam structures of radio frequency microelectromechanical systems (RF MEMS) switches. In this release process a combination of wet and dry etching has been used. The wet etching is done to remove the sacrificial layer under the beam structure. The dry release of the cantilever beam structures was done by removing the supporting layer of photoresist using the reactive ion etching technique (RIE). The power and pressure factors were varied for anisotropic and isotropic etching during the RIE process thus getting the free standing MEMS structures. The release process can effectively be used in the fabrication of suspended beams and membrane structures for RF MEMS switches. The process is not only fully compatible with standard MEMS processing equipments but could also lead to the long term storage of the MEMS devices.