Mems device and manufacturing method thereof

Abstract

A manufacturing method of microelectromechanical system (MEMS) device includes providing a first, a second and a third substrates, wherein the first substrate includes a first and a second circuit, the second substrate includes second and third connection areas, and the third substrate includes first connection areas. Second grooves and a dividing groove are formed on the fourth surface of the third substrate. The second and third substrates are bonded to make the first and the second connection areas correspondingly connect with each other. The second substrate is divided to form electrically isolating first and second movable elements. The first movable element is spatial separated from the third substrate and corresponding to the second groove. The second movable element is connected to the third substrate. The first and the second substrates are bonded to make the fourth and the third connection areas connect correspondingly. The third substrate is thinned, divided into a first and a second cap from the dividing groove, and formed a first groove from the fifth surface. The first cap is corresponding to the first movable element and the first circuit. Air tight space to sense a pressure variation of exterior environment is formed between the first substrate and the second cap. The second movable element is movable with the second cap by the pressure variation of the exterior environment. Accordingly, the pressure sensor and the MEMS structure for sensing other physical quantity can be integrated in the foregoing MEMS device by a single process.