Media-compatible electrically isolated pressure sensor for high temperature applications

Abstract

A method for manufacturing a Micro-Electro-Mechanical System pressure sensor, including forming a gauge wafer including a diaphragm and a pedestal region. The method includes forming an electrical insulation layer disposed on a second surface of the diaphragm region and forming a plurality of sensing elements patterned on the electrical insulation layer disposed on the second surface in the diaphragm region, forming a cap wafer with a central recess in an inner surface and a plurality of through-wafer embedded vias made of an electrically conductive material in the cap wafer, creating a sealed cavity by coupling the inner recessed surface of the cap wafer to the gauge wafer, such that electrical connections from the sensing elements come out to an outer surface of the cap wafer through the vias, and attaching a spacer wafer with a central aperture to the pedestal region with the central aperture aligned to the diaphragm region.