Episeal pressure sensor and method for making an episeal pressure sensor

摘要

A method for making a pressure sensor by providing a wafer including a base silicon layer, a buried sacrificial layer, and a top silicon layer. The top silicon layer is arranged over the buried sacrificial layer and the buried sacrificial layer is arranged over the base silicon layer. Etching vents through the top silicon layer to the buried sacrificial layer and removing a portion of the buried sacrificial layer. Depositing silicon to seal the vents and arranging a strain gauge or a capacitance contact on the wafer. A method for making a pressure sensor including providing a bulk wafer and depositing a sacrificial layer on the bulk wafer. Depositing silicon on the sacrificial layer and the bulk wafer to form an encapsulation layer. Etching vents through the encapsulation layer to the sacrificial layer and removing the sacrificial layer. Closing the vents with a silicon deposition and arranging a strain gauge or a capacitance contact on the encapsulation layer. A pressure sensing device including a substrate, an encapsulation layer with vents, and voids between the substrate and the encapsulation layer. A portion of the encapsulation layer above the voids forms a membrane and deposited silicon plugs fill the vents. A strain gauge or a top capacitive contact arranged on the membrane.