Patent ID: 7683636

Claim:
An improved relative humidity sensor apparatus, comprising: a semiconductor substrate and a first insulator layer formed on said semiconductor substrate in association with a second insulator layer formed on said first insulator layer; a P-plus layer and a P-well layer formed on a perimeter of said semiconductor substrate wherein said P-plus layer and said P-well layer create a path for a parasitic capacitance caused by water condensation to connect to at least one node of a sensing capacitor; a pair of contacts associated with a pair of capacitor plates formed on said second insulator layer, wherein said pair of capacitor plates are isolated from one another with a space formed therein; and a humidity sensitive dielectric layer formed on said second insulator layer and said pair of capacitor plates, wherein a relative permittivity of said humidity sensitive layer varies in accordance with a humidity such that a pair of series capacitance additionally varies in accordance with said humidity to thereby provide an increased accurate measurement of said humidity.