Electrical contact for a MEMS device and method of making

摘要

A method for making a subsurface electrical contact on a micro-electrical-mechanical-systems (MEMS) device. The contact is formed by depositing a layer of polycrystalline silicon onto a surface within a cavity buried under a device silicon layer. The polycrystalline silicon layer is deposited in the cavity through holes etched through the device silicon and reseals the cavity during the polycrystalline silicon deposition step. The polycrystalline silicon layer can then be masked and etched, or etched back to expose the device layer of the micromachined device. Through the layer of polycrystalline silicon, a center hub of the device may be electrically contacted.