A new model is proposed for the low-frequency piezoelectric activity of ZnO films grown on CVD SiO2. In this MOS structure, with ZnO as the semiconductor, a depletion layer is induced by means of a d.c. bias voltage. Using standard semiconductor theory, an expression is derived relating the electric field in this depletion layer with the driving a.c. and d.c. voltages. Due to the built-in charge at the ZnO-SiO2 interface, a depletion layer exists, even when no d.c. bias is applied. We measured the vibration amplitude at resonance of the tip of a silicon cantilever, upon which the MOS structure was deposited, as function of a.c. and d.c. voltages. The results show good agreement with calculated curves.
|Number of pages||3|
|Journal||Sensors and actuators. A: Physical|
|Publication status||Published - Feb 1990|
|Event||5th International Conference on Solid-State Sensors and Actuators and Eurosensors III, Transducers '90 - Eurosensors III - Montreux, Switzerland|
Duration: 25 Jun 1989 → 30 Jun 1989
Conference number: 5