CMOS microelectromechanical system (MEMS) device and fabrication method thereof

摘要

A method for fabricating the MEMS device includes providing a substrate. Then, a structural dielectric layer is formed over the substrate at a first side, wherein a diaphragm is embedded in the structural dielectric layer. The substrate is patterned from a second side to form a cavity in corresponding to the diaphragm and a plurality of venting holes in the substrate. An isotropic etching process is performed from the first side and the second side of the substrate via vent holes to remove a dielectric portion of the structural dielectric layer for exposing a central portion of the diaphragm while an end portion is held by a residue portion of the structural dielectric layer.