臺灣博碩士論文加值系統

光具有低傳輸損耗、低干擾等優點，因此是最佳之通訊媒介，可大幅增加通訊速度。其中光調變器為最關鍵的元件之一，為現代光通訊不可或缺之元件。本論文旨在設計與量測熱光吸收調變器，以側向自我電熱加熱結構改變溫度，以調變材料之吸收曲線以及穿過之光強度。本論文研究、設計與製作調變器結構，建立一套GOI低溫黏合製程技術，能有效地控制鍺層厚度與表面均勻度。元件加熱方式乃利用半導體材料與金屬之間不同的電阻率，在加電壓的過程中因為不同電阻率造成不同的壓降，由於半導體材料的電阻值大於金屬的電阻值，造成大部分的壓降會落至半導體材料，使其溫度增加。此調變器主要以絕緣層上覆鍺結構來製作元件材料，因鍺與其他半導體材料相比，具有陡峭的光吸收係數曲線，故在單位溫度變化下，光吸收係數曲線即會有顯著的變化，且使用鍺為主要材料也有利於結合矽製程與光電系統。此外，結構中間加一層金屬反射器，可使得光線通過反射器反射在鍺層形成共振腔效果，提升有效光路徑，增加調變效果。本GOI熱光吸收光調變器，在0.8V與1.2V的偏壓下，造成元件本身的溫度改變，可觀察鍺的吸收曲線偏移。在1563nm的波長下，光調變對比度可達8.71dB。因此本論文成功驗證熱光吸收調變器為一有效且低操作電壓、高對比度，符合商用通訊波段之元件。

The optical communication has advantages in high capacity, low transmission loss, and low interference, therefore it is one of the best communication methods and can significantly enhance the communication speed. The optic modulator is indispensable part in modern high-speed optical communication system. This thesis study is focused on the design, fabrication, and measurement of novel thermo-absorption optical modulators, which utilize lateral self-resistive-heating method to change the device temperature and modulate the light intensity passing through the device. The heating mode utilizes the difference of resistivity between semiconductor materials and metals, thus most of the voltage drop is applied on the semiconductor region to increase the temperature due to its higher resistance. The modulator devices are based on the germanium-on-insulator (GOI) structure. We also establish a process of GOI bonding technology at low temperature that can effectively control the germanium thickness and the surface uniformity. Comparing with other semiconductor materials, germanium has a steep optical absorption curve and therefore the curve can move fast with varying temperature; the use of germanium as the device material is also beneficial to the integration of silicon process technology and electro-optical system. Besides, a bottom metal reflector structure is used to induce cavity effect and to enhance effective light path as well as modulation effect. When the GOI thermo-absorption optical modulator is biased at 0.8V or 1.2V, the increasing temperature causes absorption curve shift. The modulation contrast reaches 8.71dB under the 1563nm wavelength. Therefore this study demonstrated that the thermo-absorption optical modulator is an effective device with low-operation-voltage and high contrast ratio and suitable for optical communication and interconnects.

中文摘要......................................................... i
英文摘要........................................................ ii
目錄............................................................ iii
圖目錄...........................................................vi
表目錄.........................................................viii

第一章、 導論
1.1光纖通訊之發展及其應用........................................1
1.2電光調變器 VS. 電制吸收光調變器 VS. 熱光調變器................2
1.3論文架構......................................................4
參考文獻........................................................5



第二章、 理論基礎及文獻回顧
2.1 熱光吸收調變原理.............................................7
2.2 絕緣層上覆半導體製造技術.....................................9
2.3 熱光調變器設計..............................................12
參考文獻.......................................................17


第三章、 實驗方法
3.1 GOI低溫黏合法製作...........................................19
3.1.1 晶片切割與清洗...........................................20
3.1.2 長氧化層薄膜.............................................20
3.1.3 金屬薄膜蒸鍍.............................................21
3.1.4 環氧樹酯黏合.............................................22
3.1.5 研磨拋光.................................................22
3.1.6 濕蝕刻...................................................24
3.1.7 表面分析.................................................24
3.1.8 厚度量測.................................................26
3.2 元件製程步驟................................................29
3.2.1 光罩設計.................................................29
3.2.2 光微影術.................................................30
3.2.3 乾蝕刻...................................................31
3.2.4 掀離法...................................................31
參考文獻......................................................34


第四章、 量測系統與結果分析
4.1 量測系統....................................................35
4.1.1 反射光譜 VS. 電壓........................................38
4.1.2 光調變...................................................40
4.2 量測結果....................................................41
參考文獻.....................................................47
第五章、 結論
5.1 總結........................................................49
5.2 未來研究方向................................................50

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[1]http://www.mellesgriot.com/products/optics/gb_2_1.htm