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Abstract

This paper reports on the design, simulation and fabrication of Surface Acoustic Wave (SAW) devices using lithium niobate (LiNbO₃) as a substrate. Sol-gel prepared doped TiO₂ thin films have been deposited onto the SAW devices by spin-coating. Modelling and simulation has been performed to predict the performance of a SAW oxygen sensor using a high frequency electronics computer software package (HP-EEsof TM). Experimental work has been carried out for the purpose of evaluating the accuracy of the simulated results. Resistivity of doped TiO₂ thin films has been found to decrease 47 fold when the oxygen concentration is decreased from 1% to 1 ppm at a working temperature of 200'C. The SAW oxygen sensor registered a 180 kHz frequency shift for the same changes in oxygen concentration. Our preliminary experiments highlighted that the doped TiO₂-coated SAW sensors can detect oxygen in the concentration range of 1 ppm-l%.

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References

Armanov I. D. 1989. "Analysis and design aspects of SAW delay line stabilized oscillation," 2nd Int. Conf Frequency Synthesis.: 36-40.

Atashbar M. Z. , H. T. Sun and W. Wlodarski . 1996 "TiO2 thin films prepared by sol-gel method for oxygen microsensor application," IEEE Proc. of Conf. on Optoelectronic & Microelectronic Materials & Devices, Canberra, Australia, 8-11 Dec. 1996.: pp. 487-490.

Atashbar M. Z. , A. Campitelli , H. T. Sun and W. Wlodarski . 1997a "Development of TiO2-coated surface acoustic wave oxygen sensor," Proc. Eurosensors XI, Warsaw, Poland, 21-24 Sept.: 427-430.

Atashbar M. Z. , M. K. Ghantasala and W. Wlodarski 1997b "Characterisation of sol-gel prepared TiO2 thin film for 02 sensing," Proc. of SPIE, Adelaide, Australia, 10-13 Dec. 1997.: 382-388.

Atashbar M. Z. , H. T. Sun , B. Gong , W. Wlodarski and R. Lamb . (In press) "XPS study of a Nb-doped oxygen sensing TiO2 thin films prepared by sol-gel method" Thin Solid Film.

Auld B. A. 1973. "Acoustic Fields and Waves in Solids," Vol.11. Wiley, New York.

Banda P. A. , W. Wlodarski and J. Scott . 1994. "Modelling aspects of surface acoustic wave gas sensor" Sensors and Actuators A, 42(1-3): 638-642.

Datta S. 1985. "Surface Acoustic Wave Devices," Prentice-Hall, Englewood Cliffs, NJ.

Gopel W. , G. Roker and R. Feierabend . 1993. "Intrinsic defects of TiO2(1 10): interaction with chemisorbed 02, H2, CO and C02" Physical Review B. 28(6): 3427-3438.

10.

Lec. R. , J. F. Vetelino , R. S. Falconer and Z. Xu . 1988. "Macroscopic theory of surface acoustic wave gas microsensors " Proc. IEEE Ultrasonic Symp., Chicago, IL, USA, 2-5 Oct.: 585-589.

11.

Ricco A. J. , S. J. Martin and T. E. Zipperian . 1985. "Surface acoustic wave gas sensors based on film conductivity changes" Sensors and Actuators, Vol. 8,:319-333.

12.

Ricco A. J. And S.J. Martin 1991. "Thin metal film characterization and chemical sensors: monitoring electronic conductivity, mass loading and mechanical properties with surface acoustic wave devices" Thin Solid Films, 206: 94-101.

13.

Slobodnik A. J. 1976. "Surface Acoustic Waves and Materials," Proc. of the IEEE, Vol. 64, No. 5: 581-595.

14.

Smith W. R. 1976. "Basics ofthe SAW interdigital transducer," Wave Electron., 2: 22-63.

15.

Takeuchi T. 1988. "Oxygen sensors," Sensors and Actuators, 14(2): 109-124.

16.

Wolhtjen H. 1984

"Mechanism of operation and design consideration for surface acoustic wave device vapor sensor,"

Sensor and Actuators, Vol. 5, 307-325.

Design,Simulation and Fabrication of Doped TiO2-Coated Surface Acoustic Wave Oxygen Sensor

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