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Author Gabl, R. ♦ Green, E. ♦ Schreiter, M. ♦ Feucht, H.D. ♦ Zeininger, H. ♦ Primig, R. ♦ Pitzer, D. ♦ Eckstein, G. ♦ Wersing, W.
Sponsorship IEEE Sensors Council
Source IEEE Xplore Digital Library
Content type Text
Publisher Institute of Electrical and Electronics Engineers, Inc. (IEEE)
File Format PDF
Copyright Year ©2003
Language English
Subject Domain (in DDC) Technology ♦ Engineering & allied operations ♦ Applied physics
Subject Keyword Film bulk acoustic resonators ♦ Biosensors ♦ Humidity ♦ Polymer films ♦ Acoustic sensors ♦ Transistors ♦ Acoustic applications ♦ Zinc oxide ♦ Frequency ♦ Silicon
Abstract In this paper the feasibility of thin film bulk acoustic resonators (FBAR), for applications in bio- and gas-detection, is shown for the first time. Solidly mounted, ZnO FBARs with frequencies around 2 GHz have been fabricated on silicon substrates. The dependence of the FBAR mass sensitivity on the design of the layer stack has been investigated exhibiting an optimized sensitivity of 2.5 Hz cm/sup 2//pg. Using a common protein assay the capability of detecting bio-molecules has successfully been proved. Gas sensing has been demonstrated by coating the FBAR with a humidity absorbing polymer. A strong non-linear dependence of the humidity sensitivity on the thickness of the polymer coating has been found. When the polymer thickness is far less than the acoustic wavelength, a pure mass dependent response occurs, leading to a negative shift in resonance frequency. Moreover, as the polymer thickness becomes significant, acoustic influences affect the response and the shift becomes large and positive. A sensitivity to humidity of up to two orders of magnitude higher than that of comparably coated quartz crystal micro-balances has been observed.
Description Author affiliation: Corp. Technol., Siemens AG, Germany (Gabl, R.; Green, E.; Schreiter, M.; Feucht, H.D.; Zeininger, H.; Primig, R.; Pitzer, D.; Eckstein, G.; Wersing, W.)
ISBN 0780381335
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research ♦ Reading
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2003-10-22
Publisher Place Canada
Rights Holder Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Size (in Bytes) 348.77 kB
Page Count 5
Starting Page 1184
Ending Page 1188

Source: IEEE Xplore Digital Library