Dynamic pressure sensor, esp. hydrophone - using thin layer of piezoelectric zinc oxide on semiconductor substrate

摘要

The sensor consists of a substrate, on which is a piezoelectric transducer layer obtd. by deposition in vacuo directly on the substrate, onto a conducting layer on the substrate. The piezoelectric layer is at least ten times thinner than the substrate, and is covered by a conducting layer. The piezoelectric layer is pref. ZnO and obtd. by cathodic bombardment. The substrate is pref. a semiconductor, esp. Si, Ge, GaAs, or InP. The sensor may consist of numerous units, each using a piezoelectric layer sandwiched between two electrodes, the lower electrode being connected to the upper electrode of the next unit. Esp. for buoys carrying numerous hydrophones for detecting submarines; and also as pressure sensors in motor vehicles. The sensors are inexpensive, but have a high signal/noise ratio.