1916年Albert Einstein根據廣義相對論預言了重力波的存在，而Russell Hulse和Joseph Taylor於1974年直接觀測到脈衝雙星系統(Hulse–Taylor binary pulsar)， 間接證實重力波的存在[1]。而雷射干涉重力波觀測站(Laser Interferometer Gravitational-Wave Observatory，LIGO)為了量測重力波的訊號架設大型Michelson 干涉儀，並於2015年9月14日首次量測到重力波的訊號，直接證實重力波的存在[2]，為科學歷史上重大的突破。
而西澳大學(The University of Western Australia，UWA) 為了增加雷射干涉重力波之偵測器的偵測靈敏度而設計一光學機構腔體[3]，此為偵測器之外部共振腔，而Cat-flap結構為此共振腔體的元件之一，其結構為以氮化矽薄膜懸吊一矽基板，矽基板的雙面鍍有高反射鏡結構。
而本論文完整說明Cat-flap結構的製作與問題討論。第二章詳細說明了Bare cat-flap的設計與製程步驟。製作完成後如何將Cat-flap取出液面為本章節之重點。筆者嘗試了自然蒸發法、臨界點乾燥法與針頭輔助蒸發法，最終成功透過針頭輔助蒸發法將Cat-flap取出液面。第三章詳述雙面鍍膜cat-flap (Double-side high reflector coated cat-flap)的製作過程並討論過程中遇到的問題，特別是水導雷射切割雙面高反射鏡時背面反射鏡所產生的損傷現象，最終透過紫外光雷射(UV laser)與水導雷射雙雷射切割的方式獲得改善。另一方面此章節亦探討磷酸去除氮化矽薄膜時磷酸對於高反射鏡表面的影響，以及矽<211>晶向被蝕刻造成高反射鏡角落懸空的底切現象。第四章針對結構優化進行製作與測試，特別著重於第三章中高反射鏡角落懸空的底切現象提出改善方式，以及如何改善高反射鏡表面的潔淨度與去除window處多餘的氮化矽薄膜。結果顯示潔淨度有所改善且多餘的氮化矽薄膜可被成功去除，但為了避免底切現象，將高反射鏡鍍膜區域縮小，反而在KOH蝕刻時高反射鏡陰影效應區域無法被氮化矽薄膜保護而被蝕刻，衍伸出額外的問題，未來我們將對此進行製作流程上的修正，以避免此現象產生。

In 1916, Albert Einstein predicted the existence of gravitational waves based on general relativity. However, the existence of gravitational waves is not easy to be proved by experimental measurement. Until 1974, Russell Hulse and Joseph Taylor observed the Hulse-Taylor binary pulsar and found out the period shift of binary pulsar becomes larger every year. This observation is the first indirect evidence for the existence of gravitational waves [1]. Laser Interferometer Gravitational-Wave Observatory (LIGO) set up two large Michelson interferometers to measure the gravitational wave signals. On September 14, 2015, the first signal of gravitational waves was measured, which confirmed the existence of gravitational waves directly [2], It is a breakthrough in the history of science
The University of Western Australia (UWA) designed an optical cavity [3], which is the external cavity of the detector using to increase the detector sensitivity of the laser interferometer. The Cat-flap structure is one of the components in the resonant cavity. The Cat-flap is composed by a silicon substrate coated with high reflective mirror on the both sides and this silicon is suspended by a silicon nitride film so that it is able to swing easily.
This paper elaborate on the fabrication and problem discussion of Cat-flap structure. The first chapter describes the motivation of Cat-flap investigation. The second chapter describes the design and process steps of bare cat-flap in detail, and the key point of this section is how to take the Cat-flap out of the water. The author had tried the natural evaporation method, the critical point drying method and pinhead assisted evaporation method. Finally, the author used pinhead assisted evaporation method to take Cat-flap out of the water successfully. The third chapter shows the production process of double-side high reflective mirror coated cat-flap and discusses the problems in the process. Especially, when the water-jet guided laser cutting double-sided high reflection mirror, a cutting damage is generated on the backside mirror surface. Eventually, the damage is improved by dual laser cutting (UV laser and water-jet guided laser). Furthermore, this section also shows that high reflective mirrors are almost undamaged during the silicon nitride removed process in phosphoric acid. The corner undercutting phenomenon caused by KOH wet etching so that the high reflection mirror is dangled at corner. The fourth chapter focuses on the fabrication testing of structure optimization including how to improve the high reflection mirror corner undercutting in Chapter 3, and how to improve the cleanliness on the high reflective mirror surface and remove the excess silicon nitride film. The result shows that the cleanliness is improved and the excess silicon nitride film can be removed successfully. In order to avoid undercutting phenomenon, the area of the high reflection mirror coating is reduced on purpose. Nevertheless, the shadow-effect area of high reflective mirror is etched by KOH, because it cannot be protected by silicon nitride film, which induces the extra issues. In the future, we expect to improve the production process to avoid this phenomenon.

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