Patent ID: 8322205
Filing Date: 2012-12-04
Classification: B60C,G01L,H01L,Y10T

Abstract:
1. A method of fabricating a pressure sensor for sensing a fluid pressure, the method comprising the steps of: providing a first wafer substrate having first and second opposing planar surfaces; depositing circuitry on the first planar surface; depositing a layer of passivation material on the circuitry; etching openings in the passivation layer to expose parts of the circuitry; etching an aperture into the first wafer from the first planar surface towards the second planar surface; depositing sacrificial material in the aperture; depositing a flexible membrane on the sacrificial material and the exposed parts of the circuitry; plasma cleaning the sacrificial material out of the aperture from the second surface; providing a second substrate; and, sealing the second substrate to the second planar surface of the first wafer substrate to define a chamber containing a fluid at a reference pressure; wherein during use, the flexible membrane deflects due to pressure differentials between the reference pressure and the fluid pressure and the circuitry converts the deflection of the flexible membrane into an output signal indicative of the fluid pressure.