High performance piezoelectric field-effect transducers and their application

The PI-DMOST and the piezoelectric thin film capacitor dual-gate D-MOST, two members of the PI-FET family, were investigated theoretically and experimentally. Both devices showed high performance, solid-state, strain microtransducers having applications in fields such as nondestructive testing and acoustic wave signal processing. An oriented piezoelectric ZnO thin-film is employed in both devices as the transducing medium. Strain sensitivity results from direct coupling of piezoelectrically induced charges to the channel of the D-MOSTs. Major advantages of these two device configurations over the transducers and previous PI-FETs are higher sensitivity, a wider range of operating frequency, faster response time, smaller and more well-defined sensing area, and compatibility with planar IC technology.