A Novel Membrane Process for RF MEMS Switches

A novel fabrication process for a fixed-fixed membrane structure in RF microelectromechanical-systems switches is implemented to alter the stress-distribution and deformation of the membrane and thus vary the required actuation force. This two-step process removes UV-light-exposed photoresist first by wet dissolution of a sacrificial photoresist layer and then by oxygen reactive ion etching. During wet release, the patterned but unexposed photoresist above the membrane helps prevent stiction. Further designs of photoresist-aided membranes are demonstrated to control the measured pull-down voltage level of the switches, which is consistent with the multiphysics simulation work.