Piezoelectric Bimorph Microphone with Low Stress Parylene Diaphragm
This paper describes a micromachined piezoelectric bimorph microphone, which is built on a low stress Parylene diaphragm with high quality ZnO films. The ZnO thin film has fine grain with the average grain size less than 1 and the grain orientation is perpendicular to the substrate. The highest sensitivity of piezoelectric bimorph microphone fabricated in this study is about 0.74 mV/Pa, which is twice higher than that of an individual segmented electrode. Based upon the experimental results, we proposed the equivalent electrical circuit model of piezoelectric bimorph microphone.
Byung Tae Ahn, Hyeongtag Jeon, Bo Young Hur, Kibae Kim and Jong Wan Park
S. H. Yi et al., "Piezoelectric Bimorph Microphone with Low Stress Parylene Diaphragm", Solid State Phenomena, Vols. 124-126, pp. 161-164, 2007