US Patent 7531424 Vacuum wafer-level packaging for SOI-MEMS devices

A device and method for fabricating the device is disclosed. The device includes a substrate having an active layer disposed on a sacrificial layer. A trench is formed in the active layer to electrically isolate first and second regions in the active layer, and a non-conductive material is deposited on the substrate such that the non-conductive material fills the trench to form a substantially planar surface for support of further components of the device. In some cases, the non-conductive material fills only a portion of the trench sufficient to form the substantially planar surface. The non-conductive material may include silicon nitride.