Humidity sensor with graphene oxide as sensing material

Humidity sensor can found wide application in industry, automobile and consumer electronics. In this work, capacitive humidity sensor structure was designed and fabricated on 200mm CMOS BEOL Line. BEOL Al was used as electrode with comb/serpent structure, and graphene oxide (GO) was used as humidity sensing material. Result shows that GO based humidity sensor has high sensitivity, faster recovery time and good linearity performance. Based on the sensor structure, prototype humidity sensor was built by PCB-level integration with dedicated readout ASIC and display/calibration module, and the output data can well match that of standard humidity product.