Improvement of Polyimide Capacitive Humidity Sensor by Reactive Ion Etching and Novel Electrode Design

[[abstract]]In this study, we demonstrate a highly sensitive polyimide capacitive humidity sensor achieved by reactive ion etching microstructures in polyimide film and novel electrode designs. For sensors of 3 μm polyimide film, the sensitivity is improved from 0.8 to 1.24 (pF/%RH) over the relative humidity ranging from 50 to 80. The hysteresis is within 2.5 (%RH). The device has 1600 humidity admittance square holes etched 2 μm deep in the polyimide sensing film, and its bottom electrode was patterned to reduce the less sensitive capacitor area to increase the dC/C ratio, and hence increase the sensitivity of the sensors.[[fileno]]2030168030009[[department]]電機工程學