System and method for forming a buried lower electrode associated with a hermetically sealed MEMS device

摘要

A system and method for forming a sensor device with a buried first electrode includes providing a first silicon portion with an electrode layer and a second silicon portion with a device layer. The first silicon portion and the second silicon portion are adjoined along a common oxide layer formed on the electrode layer of the first silicon portion and the device layer of the second silicon portion. The resulting multi-silicon stack includes a buried lower electrode that is further defined by a buried oxide layer, a highly-doped ion implanted region, or a combination thereof. The multi-silicon stack has a plurality of silicon layers and silicon dioxide layers with electrically isolated regions in each layer allowing for both the lower electrode and an upper electrode. The multi-silicon stack further includes a spacer that enables the lower electrode to be accessible from a topside of the sensor device.