Authors: M. Zanga, S.M. Zurn, D.L. Polla, B.J. Nelson and W.P. Robbins
Affilation: University of Minnesota, United States
Pages: 265 - 268
Keywords: PZT thin film bridge, microtransducer, PZT thin film, microsensor, deep trench RIE
ANSYS simulation of a variety of microtransducers was performed. The results indicate that a bridge structure is an optimal design for a microtransducer. Simulation of a bridge structure PZT thin film microtransducer was verified by fabricating the device on silicon wafers using reactive ion etching (RIE) and bulk micromachining techniques. The bridge of the microtransducer is released by back etching of the silicon wafer using an STS RIE system. One advantage of the STS RIE system is that is allows more than six wafers to be etched at one time, as opposed to deep trench RIE systems. The complexity of the fabrication process is also greatly reduced using this combination of processes. Analytical results of the frequency response closely agree with experimental results. Testing and simulation verified that the bridge structure PZT thin film transducer is more sensitive than other structures, such as membranes, cantilever beams and sandwich structures. The bridge transducer has a Q factor of 500.