Sezawa mode SAW pressure sensors based on ZnO/Si structure

Author

Talbi, Abdelkrim ; Sarry, Frederic ; Le Brizoual, Laurent ; Elmazria, Omar ; Alnot, Patrick

Author_Institution

Lab. de Phys. des Milieux Ionises et Application, Univ. Henri Poincare Nancy I, France

Volume

51

Issue

11

fYear

2004

Firstpage

1421

Lastpage

1426

Abstract

Surface acoustic wave (SAW) devices have been shown to be suitable for many sensor applications. One of these applications is pressure sensor. In this study we investigate the performance of SAW pressure sensors formed with ZnO/Si(001) structure. The pressure sensitivities of Rayleigh mode as well as the Sezawa mode are studied as a function of normalized thickness (kh=2/spl pi/h/sub ZnO///spl lambda/). The experimental results show an opposite strain effect in the ZnO layer and Si substrate. A theoretical approach based on the perturbation method has been developed for the evaluation of pressure sensitivity in the Sezawa mode. Experimental and theoretical results obtained for the ZnO/Si SAW sensor prepared with kh=1.18 are in good agreement. For kh/spl les/1.2, the ZnO contribution to the sensor sensitivity can be neglected in the Sezawa mode in which ZnO acts mainly as an electromechanical conversion layer.

Keywords

II-VI semiconductors; elemental semiconductors; piezoelectric thin films; pressure sensors; silicon; surface acoustic wave sensors; zinc compounds; Rayleigh mode; SAW devices; Sezawa mode SAW pressure sensors; Si substrate; ZnO layer; ZnO-Si; ZnO/Si structure; electromechanical conversion layer; pressure sensitivity; strain effect; surface acoustic wave SAW devices; Acoustic sensors; Acoustic waves; Capacitive sensors; Electromechanical sensors; Perturbation methods; Piezoelectric films; Sputtering; Substrates; Surface acoustic waves; Zinc oxide;

fLanguage

English

Journal_Title

Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on

Publisher

ieee

ISSN

0885-3010

Type

jour

DOI

10.1109/TUFFC.2004.1367481

Filename

1367481