Abstract: The present invention provides a MEMS pressure sensor and a manufacturing method. The pressure is formed by a top cap wafer, a MEMS wafer and a bottom cap wafer. The MEMS wafer comprises a frame and a membrane, the frame defining a cavity. The membrane is suspended by the frame over the cavity. The bottom cap wafer closes the cavity. The top cap wafer has a recess defining with the membrane a capacitance gap. The top cap wafer comprises a top cap electrode located over the membrane and forming, together with the membrane, a capacitor to detect a deflection of the membrane. Electrical contacts on the top cap wafer are connected to the top cap electrode. A vent extends from outside of the sensor into the cavity or the capacitance gap. The pressure sensor can include two cavities and two capacitance gaps to form a differential pressure sensor.
Abstract: The present invention provides a MEMS pressure sensor and a manufacturing method. The pressure is formed by a top cap wafer, a MEMS wafer and a bottom cap wafer. The MEMS wafer comprises a frame and a membrane, the frame defining a cavity. The membrane is suspended by the frame over the cavity. The bottom cap wafer closes the cavity. The top cap wafer has a recess defining with the membrane a capacitance gap. The top cap wafer comprises a top cap electrode located over the membrane and forming, together with the membrane, a capacitor to detect a deflection of the membrane. Electrical contacts on the top cap wafer are connected to the top cap electrode. A vent extends from outside of the sensor into the cavity or the capacitance gap. The pressure sensor can include two cavities and two capacitance gaps to form a differential pressure sensor.