A semiconductor structure includes a first device and a second device. The first device includes a plate including a plurality of apertures, a membrane disposed opposite to the plate and including a plurality of corrugations facing the plurality of apertures, and a conductive plug extending from the plate through the membrane. The second device includes a substrate and a bond pad disposed over the substrate, wherein the conductive plug is bonded with the bond pad to integrate the first device with the second device, and the plate is an epitaxial (EPI) silicon layer or a silicon-on-insulator (SOI) substrate.