METHOD OF FABRICATING MEMS DEVICE HAVING RELEASE ETCH STOP LAYER

A method of fabricating a microelectromechanical (MEMS) device includes bonding a transducer wafer to a substrate wafer along a bond interface. An unpatterned transducer layer included within the transducer wafer is patterned. A release etch process is then performed during which a sacrificial layer is exposed to a selected release etchant to remove at a least a portion of the sacrificial layer through the openings in the patterned transducer layer. A release etch stop layer is formed between the sacrificial layer and the bond interface prior to exposing the sacrificial layer to the release etchant. The release etch stop layer prevents the ingress of the selected release etchant into the region of the MEMS device containing the bond interface during the release etch process.