利用射頻磁控濺鍍法在具有氧化鋁緩衝層之玻璃基板上沉積氧化鋅薄膜以作為高頻表面聲波之應用

Fabrication of high frequency SAW devices with ZnO thin film on Al2O3/glass substrates by RF sputtering

彭彥凱(Yan-Kai Peng)

指導教授 ： 施文欽

大同大學/電機資訊學院/光電工程研究所/碩士(2010年)

摘要

摘要
表面聲波元件是在壓電基板上利用壓電換能原理的特性，做各種訊號的處理。目前通訊元件有朝著高頻化的發展趨勢，而高頻表面聲波元件須具有高波速，高機電耦合係數，低插入損失等特性，經由壓電薄膜與不同基底材料或緩衝層所組成之表面聲波元件不但可以提高表面聲波元件操作頻率以及增加機電耦合係數，因此在講求輕薄短小的行動通訊產品中已被大量使用。

本研究在Glass(Corning 7059)基板上，先使用電子束蒸鍍法來沈積Al2O3薄膜作為實驗上之緩衝層後，再使用射頻磁控濺鍍法來沈積ZnO薄膜作為壓電材料，比較在不同厚度的Al2O3薄膜之表面聲波元件頻率響應變化，並和Glass 及sapphire 基板作比較，研究結果顯示在IDT/ZnO/Al2O3/Glass上隨著氧化鋁薄膜厚度增加時，波速會由2710.0 m/s提升至3227.6 m/s，希望以電子束蒸鍍法來沈積Al2O3薄膜可以取代藍寶石基板進而降低成本，將來可以提供作為高頻表面聲波元件之製作。

關鍵字

玻璃 ； 表面聲波 ； 氧化鋅

並列摘要

Abstract
Now communication elements are developing towards high frequency. SAW (Surface acoustic wave, 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 and the electromechanical coupling coefficient. Consequently, SAW devices have been widely applied in mobile communication due to their small size and light weight.
This study employs Al2O3 thim film as the experimental buffer layer on glass(Corning 7059) substrate and ZnO as the piezoelectric material to contrast the frequency responses of SAW devices. We use Al2O3 buffer layers with different thicknesses and compare with the glass and sapphire substrates. Successfully, the phase velocity of IDT/ZnO/Al2O3/Glass with Al2O3 thin film has been improved to increase from 2710.0 to 3227.6 m/s . e-beam evaporated Al2O3 buffer layers with high velocity of wave has been proved to lower the cost and shorten the time of production. The method is sure of producing high frequency SAW devices,with lower cost.

並列關鍵字

Glass ； ZnO ； SAW

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