Ultrathin metallic membranes to be used in tunable RF MEMS volume capacitors

This paper presents a self-controlled reactive ion etching (RIE) bulk process to fabricate reliable and high precision suspended thin metallic membranes. The procedure includes a mechanism for the automatic stop of the RIE process, avoiding the stiction problem that appears when a wet etching is performed. These membranes can be used as movable plates in low DC controlled silicon microcapacitors for RF applications.