透過電子束蒸鍍法在矽晶片上沉積氧化鋁薄膜以作為高頻氧化鋅薄膜表面聲波元件

Fabrication of Al2O3 film on Si substrate by e-beam evaporation for high frequency ZnO thin film SAW device

朱銘賢(Ming-hsien Chu)

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(2009年)

摘要

表面聲波元件是在壓電基板上利用聲電換能原理的特性，做各種訊號的處理。目前通訊元件有朝著高頻化發展的趨勢，而高頻表面聲波元件需具有高波速、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之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地使用。
本研究使用氧化鋁 (Al2O3) 作為實驗上之緩衝層，固定ZnO/C-sapphire第二模態之氧化鋅 (ZnO) 膜厚，使用氧化鋅 (ZnO) 壓電材料，比較在不同厚度氧化鋁緩衝層之表面聲波元件其頻率響應變化，並和SiO2/Si 及sapphire 基板作比較。研究結果顯示，中心頻率如預期有所提升，同時以電子束蒸鍍法成長高波速緩衝層可以降低成本，並縮短製程時間，將來亦可以提供作為高頻表面聲波元件之製作。

關鍵字

氧化鋁 ； 氧化鋅 ； 第二模態

並列摘要

Now communication elements are developing towards high frequency. SAW devices must have high velocity, high electromechanical coupling coefficient, 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 as the experimental buffer layer and ZnO as the piezoelectric material according to the second mode of ZnO/C-sapphire to contrast the frequency responses of SAW devices. We use Al2O3 buffer layers with different thicknesses and compare with the SiO2/Si and sapphire substrates. The result of the center frequency has been improved. Preparation of Al2O3 buffer layers with high sound velocity using electron beam evaporation has been proved to lower the cost and shorten the time of production.

並列關鍵字

Al2O3 ； ZnO ； second mode

參考文獻

27. 王惠民，" 利用電子束蒸鍍法沉積氧化鋁緩衝層以作為高頻氧化鋅薄膜表面聲波元件之應用 "，大同大學光電工程研究所 (2007).

22. 王偉姍，" ZnO/Sapphire層狀表面聲波元件之分析、製作與量測 "，國立臺灣大學應用力學研究所 (2002).

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