Using e-beam evaporation to fabricate Al2O3 film on glass substrate for high frequency ZnO thin film SAW devices

• Main Authors: Chia-chi Chang, 張家齊
• Other Authors: Mu-Shiang Wu
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/14957572528651641272

碩士 === 大同大學 === 光電工程研究所 === 98 === Now communication elements are developing towards high frequency. SAW devices must have high velocity, high electromechanical coupling coefficient and low insertion loss. SAW devices composed of the piezoelectric thin film and different substrate materials or buffer layers can improve the operating frequency of SAW devices. Consequently, SAW devices can be widely applied in mobile communication due to their small size and light weight. This study employs Al2O3 thin film as the experimental buffer layer on glass (Corning 7059) substrate and ZnO film as the piezoelectric material to contrast the frequency responses of SAW devices. We use Al2O3 buffer layers with different thicknesses on the ZnO/Al2O3/glass structure. Successfully, the phase velocity of ZnO/IDT/Al2O3/Glass with Al2O3 thin film was increased from 2566.56 to 2823.48 m/s. The e-beam evaporated Al2O3 buffer layers with high velocity have been proved to lower the fabrication cost.