Title :
ZnO thin films for high frequency SAW devices
Author :
Ieki, H. ; Kadota, Mitsuhiro
Author_Institution :
Murata Manuf. Co. Ltd., Kyoto, Japan
Abstract :
Sezawa wave on a ZnO/sapphire substrate is applied to low insertion loss surface acoustic wave (SAW) filters in microwave band of 1.5 GHz to 2.5 GHz range. RF planar magnetron sputtering (RF-Mg) is used for the fabrication of epitaxial ZnO film. Sputtering conditions and the dopant are decided to realize a stable and reproducible process. Details of ZnO epitaxial growth and practical application results are reviewed. To improve the piezoelectric properties of ZnO film, electron cyclotron resonance (ECR) sputtering is investigated. The ZnO/quartz substrate has small temperature coefficient of frequency (TCF) and medium electromechanical coupling coefficient (ks) comparable to ST cut quartz and Li2B4O7 respectively. Theoretical and experimental results are also discussed.
Keywords :
II-VI semiconductors; piezoelectric thin films; semiconductor epitaxial layers; sputter deposition; surface acoustic wave filters; vapour phase epitaxial growth; zinc compounds; 1.5 to 2.5 GHz; Al2O3; RF planar magnetron sputtering; SAW filters; Sezawa wave; ZnO; ZnO/sapphire substrate; electromechanical coupling coefficient; epitaxial growth; high frequency SAW devices; piezoelectric properties; thin films; Acoustic waves; Frequency; Insertion loss; Magnetic separation; Piezoelectric films; Sputtering; Substrates; Surface acoustic wave devices; Thin film devices; Zinc oxide;
Conference_Titel :
Ultrasonics Symposium, 1999. Proceedings. 1999 IEEE
Conference_Location :
Caesars Tahoe, NV
Print_ISBN :
0-7803-5722-1
DOI :
10.1109/ULTSYM.1999.849403
