CAPACITY TYPE HUMIDITY SENSOR

PROBLEM TO BE SOLVED: To provide a capacity type humidity sensor capable of reducing an offset voltage simply and being made small-sized in its body. SOLUTION: In the capacity type humidity sensor 10, which is constituted so that a detection part 20 comprising detection electrodes 21 and 22 and a humitity-sensitive film 23 and a reference capacity part 30 comprising reference electrodes 31 and 32 and a humidity permeable film 33 which is a capacity-adjusting film are provided on a semiconductor substrate 12 and capacity difference (Cs-Cr) between the detection electrodes 21 and 22 and the reference electrodes 31 and 32 is converted to a voltage signal via a C-V conversion circuit 50 to detect humidity, the electrode patterns of the reference electrodes 31 and 32 are almost the same as those of the detection electrodes 21 and 22 and the humidity permeable film 33, having a dielectric constant almost equal to that of the humidity-sensitive film 23, when humidity is in a reference state (e.g., humidity: 0% RH (relative humidity)) is provided on the reference electrodes 31 and 32. Since offset voltage can be reduced only by providing the humidity permeable film 33 and the body of the sensor 10 can be miniaturized, without requiring an offset correction circuit or the like. COPYRIGHT: (C)2005,JPO&NCIPI