Compound sacrificial layer process for RF MEMS applications

Compound sacrificial layer has been developed for RF membrane bridge switch in micro electro mechanical systems (MEMS) tunable filters. The compound sacrificial layer consisting of polyimide and positive photoresist is used to avoid drawbacks which will occur when only polyimide or positive photoresist is used as sacrificial layer for suspended membrane with large area. The wet etching and dry etching are used to remove positive photoresist and polyimide, respectively. And the results of baking and etching of sacrificial layer are improved. The time is also shortened for the complete removal of sacrificial layer.