Patent ID: 6867602

Claim:
A method for balancing capacitance of a top plate associated with at least two capacitors to provide a common series capacitive circuit in a semiconductor-based humidity sensor, comprising the steps of: (a) providing a humidity sensor having a series capacitive circuit including a common top plate for first and second capacitors, Cx 1 and Cx 2 respectively, Cx 1 further comprising a first bottom plate and Cx 2 further comprising a second bottom plate, said common top plate, Cx 1 and Cx 2 being separated by a common, humidity-sensitive dielectric material wherein changes in humidity affect said common, humidity sensitive dielectric material and thereby changes the capacitive value of said series capacitive circuit; (b) conducting capacitive measurement of said first and second capacitors by sampling signals rendered by said first and second capacitors while connected in series in a closed loop circuit to determine the capacitive values of Cx 1 and Cx 2 during said measuring cycle; and (c) adjusting the capacitive values of Cx 1 and Cx 2 by creating voids in said top plate to keep the values of Cx 1 and Cx 2 substantially equal.