西元1915年在愛因斯坦的廣義相對論預測了重力波的存在後，科學家們用盡各種方法想要證明它的存在，但並沒有人直接量測到重力波的訊號。雷射干涉重力波觀測站(Laser Interferometer Gravitational-Wave Observatory, LIGO)利用大型麥克森干涉儀來量測重力波訊號，在西元2015年9月14號上午9點15分，LIGO於美國華盛頓州的漢福德區觀測站與路易斯安那州的利文斯頓觀測站量到了來自雙黑洞聚合所產生的重力波訊號，直接證明了重力波的存在。為了增加偵測器的靈敏度，The University of Western Australia(UWA)設計了一Cat-flap結構，將應用在重力波天文學上。
本論文研究Cat-flap結構的製作方法，此結構為以Silicon Nitride薄膜懸掛以Silicon做為基板的高反射鏡，首先從其結構出發，先在矽基板上鍍製高反射鏡，再鍍上懸掛用的Silicon Nitride薄膜，接著以黃光微影製程定義出Window的位置，再以乾蝕刻去除Window內的SiN薄膜，露出Silicon，然後將Wafer切成一個個的試片進行蝕刻，而不蝕刻的部分以SiN與ProTEK B3保護，蝕刻完成後保留懸掛用的SiN薄膜，並將其餘的部分去除，完成整個Cat-flap結構。考慮到此製程步驟中最難的部分是以KOH蝕刻出Cat-flap結構，故提出兩種蝕刻;方式來討論：分別為Direct-formation以及Well-etching，此兩種蝕刻方式是直接在雙面鍍製SiN薄膜的晶圓上利用為影技術定義圖形，接著以乾蝕刻將Window內的SiN打穿而露出Silicon後直接將Silicon蝕刻完，相較於鍍製高反射鏡的製程，此兩種方法可以快速檢驗此Cat-flap結構是否能在蝕刻完Window內的Silicon後順利以SiN薄膜支撐下方的Pendulum。
結果發現Direct-formation蝕刻方式在利用厚度為100µm的矽晶圓，且Window寬度在蝕刻完Silicon後為30µm~400µm之間時，Cat-flap結構可以順利形成，並且在蝕刻時能同時觀察到SiN應力釋放使基板彎曲形變的情形。
在蝕刻後需要將完成的Cat-flap試片拿離液體表面，但因為此結構是以薄膜作為支撐，故其結構非常脆弱，初次嘗試是將燒杯內的KOH溶液利用稀釋的方式置換成DI Water後再慢慢將水抽離，使得試片能夠露出液體表面，但仍發現水給予的表面張力過大，會將試片拉扯斷裂，接著使用自然蒸發的方式發現可以成功將試片取出液面，但因為Window內仍含有些許水分使得拿出水面的瞬間Window內水的內聚力讓蝕刻所露出之Silicon<111>晶面形成optical contact而相黏。
另一種蝕刻方法:Well-etching是將矽基板上定義一個方框的SiN薄膜，接著去除其側壁而形成以SiN懸掛的薄膜，但因為<110>晶面被蝕刻時會同時露出難以蝕刻的<111>晶面，最後<110>晶面被蝕刻完剩下<111>晶面時，此結構就不會如預期的形成Cat-flap結構。

Since gravitational waves (GW) had been predicted by Albert Einstein in 1915, scientists have tried to direct measure it, but nevertheless no one has succeeded until September 14th, 2015, Laser Interferometer Gravitational-Wave Observatory (LIGO) used large-scale Michelson interferometer to measure gravitational wave signals. Two observatories of LIGO located in Hanford, WA, and Livingston, LA had measured the gravitational waves from coalescence of two binary black holes. For further improving sensitivity of the detectors toward practical application for gravitational waves astronomy, acitivities have been taken place in every aspect of the detector related technologies. A “cat-flap” structure proposed by University of Western Australia (UWA) is one of such activities.
The aim of this paper is to study the fabrication methods for the cat-flap structure. It is a double-sided high reflector coated silicon pendant that is suspended by a silicon nitride film. At first, the high reflective mirror coatings will be coated on the silicon wafer, then SiN thin film is deposited for suspension. After this, we identify the window area through photolithography process before removing SiN film by using dry etching to make silicon surface in the window area be exposed, then we etch the sliced sample pieces from wafer. During KOH etching process, we use SiN film and ProTEK B3 on other area to prevent etching. After KOH etching is done, we will preserve the SiN film for suspension and remove the other part to form a complete Cat-flap resonator. Considering that the most difficult part of this process: etching the Cat-flap structure with KOH, we proposed two etching methods: Direct-formation and Well-etching. The two etching methods are used to define the pattern on the double-side SiN coated silicon wafer through the photolithography, then etching the SiN film in the window by dry etching to expose the silicon and using KOH to etch the silicon in the window area. These two methods can provide quick verifications whether the Cat-flap structure can successfully support the pendant below the SiN film.
With the direct-formation method, the Cat-flap structure can be successfully formed by using silicon wafers with a thickness of 100μm and window widths between 30μm and 400μm after etching silicon, and we could observe the SiN stress-release process that causes the substrate to bend and deform during the etching.
After etching, sample is lifted off the water, yet the structure is fragile because it is supported by thin film. The first attempt was to replace the KOH solution in the beaker with dilution to DI Water and then slowly withdraw the water to make the sample be exposed. But due to strong surface tension of water, the sample was broken; To our delight, we found that the sample could be successfully removed from the liquid through natural evaporation. But silicon <111> crystal plane on both silicon pieces (the pendant and the main body) form an optical contact on curving during the stress release such that two pieces stuck together.
Another etching method: Well-etching is to define a SiN membrane on the silicon, then gradually removing one pair of the opposite side walls to form the suspended SiN out of the membrane. However, when the <110> plane was etched, the <111> plane was exposed simultaneously and that stopped the etching process. Therefore, the well-etching method was not successful.

致謝 II
摘要 III
Abstract V
目錄 VII
Content X
圖目錄(Figure Content) XIII
表目錄(Table Content) XVIII
第一章 導論 (Introduction) 1
1-1 前言 (Foreword) 1
1-2 研究動機 (Motivation) 2
第二章 Cat-flap結構與製程設計 (Cat-flap structure and process design) 3
2-1 Cat-flap結構 (Cat-flap structure) 3
2-2 Cat-flap製程設計 (Cat-flap process design) 4
2-2.1 Direct-formation介紹 (Direct-formation) 10
2-2.2Well-etching介紹 (Well-etching) 11
第三章 KOH蝕刻 (KOH etching) 13
3-1 Direct-formation蝕刻 (Direct-formation etching) 13
3-1.1 寬window(寬度為millimeter等級)之KOH蝕刻 (KOH etching of the wide window(window width: millimeter level) sample) 14
3-1.1.1 使用500µm厚度之基板 (Using substrates of thickness of 500µm) 14
3-1.1.2 使用100µm厚度之基板 (Using substrates of thickness of 100µm) 17
3-1.1.3 降低蝕刻溫度 (Decreasing the etching temperature) 19
3-1.1.4 小結 (Summary) 20
3-1.2 窄window(寬度為micrometer等級)之KOH蝕刻 (KOH etching of the narrow window(window width: micrometer level) sample) 20
3-1.2.1 Window寬度為30µm之KOH蝕刻 (KOH etching of window width: 30µm samples) 22
3-1.2.2 window寬度為300µm之KOH蝕刻 (KOH etching of window width: 300µm samples) 23
3-1.3 sample拿離液面 (Taking the samples out of the water surface) 26
3-2well-etching蝕刻 (Well-etching etching) 36
3-2.1結果與討論 (Results and discussion) 37
第四章 結論與未來工作 (Conclusion and Future Work) 38
4-1結論 (Conclusion) 38
4-2未來工作 (Future work) 39
附錄A UWA試片製作(HR double sides coating cantilever) 42
A-1 試片需求 (Requirements of the samples) 42
A-1.1 試片結構 (Structure of the sample) 42
A-1.2 鍍製材料與需求 (Deposition materials and their needs) 44
A-2 鍍膜遮罩設計 (Design of the mask) 47
A-3 鍍製結果 (Results of the deposition) 54
A-4 雷射切割 (Laser cutting) 56
A-4.1水導雷射切割 (Water jet-guided laser cutting) 56
A-4.2 切割結果 (Results of laser cutting) 56
A-4.3 未來工作 (Future work) 59
附錄B 製程機台介紹 (Introduction of process machines) 61
B-1 PECVD (Plasma enhanced chemical vapor deposition) 61
B-1.1介紹與操作方法 (Introduction and methods of operation) 61
B-2 HMDS烤箱 (HMDS oven) 64
B-2.1介紹與操作方法 (Introduction and methods of operation) 64
B-2.2注意事項與疑難排解 (Notes and troubleshooting) 66
B-3 雙面光罩對準曝光機 (Double side mask aligner) 68
B-3.1介紹與操作方法 (Introduction and methods of operation) 68
B-3.2注意事項與疑難排解 (Notes and troubleshooting) 73
B-4 介電材料活性離子蝕刻系統(RIE) (Dielectric Materials Reactive Ion Etching System,RIE-200L) 74
B-4.1介紹與操作方法 (Introduction and methods of operation) 74
B-4.2注意事項與疑難排解 (Notes and troubleshooting) 77
Reference 79

[1] Joel M. Weisberg, Joseph H. Taylor “The Relativistic Binary Pulsar B1913+16: Thirty Years of Observations and Analysis”, Binary Radio Pulsars ASP Conference Series, Vol. 328, 2005 F. A.
[2] B. P. Abbott, et al, “Observation of Gravitational Waves from a Binary Black Hole Merger” PRL 116, 061102, 2016.
[3] Michael A. Page, et al, “Towards thermal noise free optomechanics”, PACS numbers: 42.50.Lc, 42.50.Pq
[4] D. R. Southworth, R. A. Barton, S. S. Verbridge, et al. “Stress and silicon nitride: A crack in the universal dissipation glasses”, Phys. Rev. Lett., Jun. 2009, 102: 225503
[5] NFC奈米中心,國立交通大學,操作規範
[6] Brewer Science® ,ProTEK® B3 User manual.
[7] Phaninder R. Kanikella, “Process development and applications of a dry film photoresist”
[8] Kirt R. Williams, Senior Member, IEEE, Kishan Gupta, Student Member, IEEE, and Matthew Wasilik, “Etch Rates for Micromachining Processing—Part II”
[9] D. B. Lee, “Anisotropic Etching of Silicon”, JOURNAL OF APPLIED PHYSICS VOLUME 40, NUMBER 11 OCTOBER 1969
[10] NCSU Nanofabrication Facility “Report on KOH Process Module Etch Characteristics and Design Guide” January 25th, 2005
[11] Virginia Semiconductor, Inc. “Wet-Chemical Etching and Cleaning of Silicon”, January 2003
[12] K.D. Mackenzie, et al, “STRESS CONTROL OF SI-BASED PECVD DIELECTRICS” Unaxis USA, Inc., 10050 16th Street North, St. Petersburg, FL 33716
[13] Prem Pal*, Sajal Sagar Singh, “A New Model for the Etching Characteristics of Corners Formed by Si{111} Planes on Si{110} Wafer Surface”, MEMS and Micro/Nano Systems Laboratory, Department of Physics, Indian Institute of Technology, Hyderabad, India
[14] 陳家全、李家維、楊瑞森著，1991，生物電子顯微鏡學，國科會精儀中心編印。
[15] Synova SA “Water jet guided laser tool machining”
[16] 黃文正 ,以離子束濺鍍法製作低損耗薄膜應用於雷射干涉重力波偵測儀之高反射鏡製程準備, 國立清華大學,碩士論文 (2012)
[17] 莊友杭 ,以電漿輔助化學氣相沈積法於矽懸臂沉積之氮化矽薄膜應力對機械損耗之影響暨機械損耗量測系統改善, 國立清華大學碩士論文(2014)
[18] Cornell NanoScale Science & Technology Facility. “ CNF - Photolithography Resist Processes and Capabilities”. [2008-01-29]
[19] OXFORD, Reactive Ion Etching(RIE)