Patent ID: 8030112

Claim:
A method for fabricating microelectromechanical system (MEMS) device, comprising: providing a single crystal substrate, having a first surface and a second surface opposite to the first surface and having a MEMS region and an integrated-circuit (IC) region; forming a plurality of SCS (single crystal structure) mass blocks on the first surface of the substrate in the MEMS region; forming a structural dielectric layer over the first surface of the substrate, wherein the structural dielectric layer has a dielectric member and spaces surrounding the SCS mass blocks in the MEMS region are filled with the dielectric member, wherein the IC region has a circuit structure with an interconnection structure formed in the structural dielectric layer; patterning the single crystal substrate by an etching process on the second surface to expose a portion of the dielectric member filled in the spaces surrounding the SCS mass blocks; and performing an isotropic etching process at least on the dielectric member filled in the spaces surrounding the SCS mass blocks, wherein the SCS mass blocks are exposed to release a MEMS structure.