| abstract |
A humidity sensor and a manufacturing method therefor. The sensor comprises, from bottom to top sequentially: a substrate (1), a cavity (3), a dielectric layer (2), a metal layer (4), at least one passivation layer (5, 6) and a sensitive layer (7). The cavity (3) is provided on the substrate (1), and is provided on the back surface of the substrate (1) or the front surface of the substrate (1). The metal layer (4) is arranged on the dielectric layer (2), and comprises a heating resistance unit (42), a detection electrode unit (43) and a bonding pad unit (41). A first passivation layer (5) is arranged on the metal layer (4), and is silicon oxide, silicon nitride or a composite layer thereof; and the passivation layer (5) on the detection electrode unit is removed by means of photolithography and etch processes. A second passivation layer (6) is arranged on the first passivation layer (5); and the first passivation layer (5) and the second passivation layer (6) on the bonding pad unit are removed by means of photolithography and etch processes. Condensed water on the surface of the humidity sensor can be removed, and the reliability of the sensor under severe working conditions is improved; and a heating unit is low in power consumption and better in heating effect. |