Experimental and computational investigation of zinc oxide based surface acoustic wave devices
Author
Özgöztaşı, Elif
Advisor
Okyay, Ali Kemal
Date
2014Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
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Abstract
Piezoelectric materials are used in different types of transducers such as microphones,
accelerometers, speakers, hydrophones, pressure sensors etc. Compared
to traditional bulk piezoelectric crystals, thin film piezoelectric materials
are promising to realize integrated devices with CMOS technology. Among thin
film materials, zinc oxide (ZnO) is attractive due to the giant piezoelectric effect
when doped with vanadium.
In this study, we investigate the deposition of thin film ZnO and V-doped
ZnO films. Materials characterization of ZnO thin films is performed. We also
investigate surface acoustic wave (SAW) devices based on ZnO thin films. SAW
devices are formed by a pair of interdigitated transducers (IDTs), input and output
IDTs. IDTs are fabricated onto the piezoelectric thin film. Applied oscillating
electric field from input IDT creates surface acoustic waves in the piezoelectric
thin film and these acoustic waves are converted back into an electrical signal
at the output IDT. SAW devices based on ZnO and V-doped ZnO films were
designed and fabricated. Frequency response of SAW devices is measured. In addition,
finite element simulations of SAW devices are shown to be in agreement
with measurement results. We discuss resonance frequency and insertion loss of
SAW devices.