Patent ID: 8841155

Claim:
A method for forming a MEMS device, comprising: providing a semiconductor substrate with a metal interconnection structure formed therein; forming a first sacrificial layer, including amorphous carbon, on the semiconductor substrate; etching the first sacrificial layer to form a first groove; forming a first dielectric layer overlaying the first sacrificial layer and the first groove; polishing the first dielectric layer until the first sacrificial layer is exposed by using a chemical mechanical polishing process; forming a micro mechanical component layer on the first sacrificial layer, where a portion of the first sacrificial layer is exposed, and a portion of the micro mechanical component layer is connected with the first dielectric layer; forming a second sacrificial layer, comprising a material same as that of the first sacrificial layer, on the micro mechanical component layer and the first sacrificial layer; etching the second sacrificial layer to form a second groove; forming a second dielectric layer overlaying the second sacrificial layer; polishing the second dielectric layer until the second sacrificial layer is exposed by using a chemical mechanical polishing process; forming an isolating layer on the second sacrificial layer; etching the isolating layer to form at least one through hole exposing the second sacrificial layer; removing the first and second sacrificial layers through the at least one through hole; and forming a covering layer on the isolating layer, wherein the covering layer covers the at least one through hole.