A method for forming a MEMS device is provided. The method includes forming a stack of layers on a base piezoelectric layer. The stack of layers includes a base metal film over the base piezoelectric layer; a first piezoelectric film over the base metal film; and a first metal film having an opening therein over the first piezoelectric film. The method also includes forming a trench in the stack of layers, wherein the trench passes through the opening in the first metal film but does not expose the base metal film; after forming the trench, forming a spacer structure under the first metal film but spaced apart from the base metal film; after forming the spacer structure, deepening the trench to expose the base metal film; and forming a contact in the trench.