Abstract
Piezoelectric gallium orthophosphate (GaPO4) thickness – shear mode resonators were patterned by F2-laser ablation and employed for gas sensing. The thickness of GaPO4 crystals was reduced from ∼215 μm to ∼115 μm by laser ablation and the piezoelectric fundamental resonance frequency in the thinned region increased thereby from ∼6 MHz to ∼12 MHz. The Q values of laser-thinned and pristine resonators in air were Q≈7000 and Q≈95000, respectively. The GaPO4 crystals were coated by thin polyimide layers that served as receptor for water vapour. The resonance frequency of coated crystals decreased linearly with increasing level of relative humidity (RH) and the sensitivity for laser-patterned 12 MHz GaPO4 resonators, SRH≈-98 Hz/% RH, was much larger than for the pristine 6 MHz GaPO4 resonators.
Similar content being viewed by others
References
D. Bäuerle: Laser Processing and Chemistry, 3rd ed. (Springer, Berlin 2000)
M. Peruzzi, J.D. Pedarnig, H. Sturm, N. Huber, D. Bäuerle: Europhys. Lett. 65, 652 (2004)
P.M. Worsch, B. Koppelhuber-Bitschnau, F.A. Mautner, P.W. Krempl, W. Wallnöfer, P. Doppler, J. Gautsch: Mater. Sci. Forum 321–324, 914 (2000)
A. Janshoff, H.-J. Galla, C. Steinem: Angewandte Chemie International Edition 39, 4004 (2000)
B. Zimmermann, R. Lucklum, P. Hauptmann, J. Rabe, S. Büttgenbach: Sens. Actuators, B 76, 47 (2001)
V.N. Hung, T. Abe, P.N. Minh, M. Esashi: Appl. Phys. Lett. 81(26), 5069 (2002)
H. Iwata: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 51(8), 1026 (2004)
N. Prudhomme, D. Cachau-Herreillat, P. Papet, O. Cambon: Proceedings of the IEEE International Frequency Control Symposium and PDA Exhibition Jointly with the 17t European Frequency and Time Forum, p. 688 (2003)
www.dupont.com/kapton/
B. Neubig, W. Briese: The Crystal Cookbook, (Franzis-Verlag, Feldkirchen 1997)
W. Shockley, D.R. Curran, D.J. Koneval: J. Acoust. Soc. Am. 41, 981 (1967)
A. Ballato, J.G. Gualtieri: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 41, 834 (1994)
J. Rabe, S. Büttgenbach, B. Zimmermann, P. Hauptmann: Proceedings of the IEEE/EIA International Frequency Control Symposium, p. 106 (2000)
G. Sauerbrey: Z. Phys. 155, 206 (1959)
J.A. Kosinski: Int. J. High Speed Electron. Sys. 10, 1017 (2000)
B. Neubig: AXTAL Advanced Xtal Products, Germany (private communication)
E.J. Uttenthaler: PhD thesis (Universität der Bundeswehr München, Germany 2002)
Author information
Authors and Affiliations
Corresponding author
Additional information
PACS
61.10.-i; 68.37.-d; 81.15.Fg
Rights and permissions
About this article
Cite this article
Pedarnig, J., Peruzzi, M., Salhofer, H. et al. F2-laser patterning of GaPO4 resonators for humidity sensing. Appl. Phys. A 80, 1401–1404 (2005). https://doi.org/10.1007/s00339-004-3186-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00339-004-3186-9