A MEMS (micro electro-mechanical system) semiconductor device and a method for producing such a device. A preferred embodiment of the present invention comprises the a wafer having a continuous BCS (bondline control structure) surrounding a MEMS active area that is affixed to an interposer layer, which is in turn affixed to a cover to form a sealed cavity over the surface of the MEMS. To fabricate this device, a wafer is populated with MEMS devices. The BCS is formed in the same process step as a device structure, for example a spacer layer. The BCS remains, however, even if all or a portion of this spacer layer is removed. In this way when the reflecting surface of the MEMS device has been formed, an interposer layer may be mounted to the BCS using a filler-less adhesive, and a cover can likewise be affixed to the interposer layer.