Abstract: A pressure sensor fabricated onto a substrate using conventional CMOS fabrication processes. The pressure sensor is built on a substrate having a first conductivity type and has defined in it a well of an opposite conductivity type. This well defines a membrane. Resistors are diffused into the well. Source/drain regions are provided for leadouts for the resistors. An n-cap is provided for the resistors. Metalization contacts may be provided to connect the membrane to a positive bias during a membrane etching process. A cavity is provided on the underside of the substrate through which pressure is applied to the membrane. Signal conditioning circuitry, such as an operational amplifier, may also be fabricated on the same substrate preferably using the same IC processes.

Abstract: An apparatus for sensing an applied force comprising a deflectable bridge, formed in a substrate and spanning a recessed area. The deflectable bridge also has a sensing element. The force is applied to the bridge and in response thereto, an output characteristic of the sensing element changes in proportion to the magnitude of the applied force. The apparatus can further comprise a sensing bump in contact with the bridge, wherein the force is applied to the bridge through the sensing bump.