SYSTEM AND METHOD FOR MINIMIZING DEFLECTION OF A MEMBRANE OF AN ABSOLUTE PRESSURE SENSOR

摘要

A Micro-Electro-Mechanical System (MEMS) pressure sensor is disclosed, comprising a gauge wafer, comprising a micromachined structure comprising a membrane region and a pedestal region, wherein a first surface of the micromachined structure is configured to be exposed to a pressure medium that exerts a pressure resulting in a deflection of the membrane region. The gauge wafer also comprises a plurality of sensing elements patterned on the electrical insulation layer on a second surface in the membrane region, wherein a thermal expansion coefficient of the material of the sensing elements substantially matches with a thermal expansion coefficient of the material of the gauge wafer. The pressure sensor comprises a cap wafer coupled to the gauge wafer, which includes a recess on an inner surface of the cap wafer facing the gauge wafer that defines a sealed reference cavity that encloses and prevents exposure of the sensing elements to an external environment.