本論文的研究目的為量子點波導研製、光電調變特性量測與分析。我們主要探討樣品的折射係數變化(Δn)、相位延遲與電光係數，藉以應用在光積體電路的光放大器、電制吸收元件、光通訊調變元件或Mach-Zehnder干涉儀上。
在光波導的材料方面，我們使用分子束磊晶機台(Molecular Beam Epitaxy,MBE)以S-K模式成長在砷化鎵基板上的砷化銦鎵之量子點磊晶片(λg=1.3μm)，包含量子點間隔層20nm、5nm未摻雜結構與在5nm的間隔層中間加入P型與N型調變摻雜的結構。
波導設計方面，我們設計了一系列的直線與傾斜7度的2.2μm單模光波導，並且利用自然劈裂面來產生Fabry-Perot resonant。元件製程方面，先利用光微影技術定義元件圖案，波導蝕刻則是採用ICP-RIE乾蝕刻與多重步驟濕蝕刻兩種技術。最後利用HBr:HCl:H2O2:H2O =5:4:1:70之蝕刻液，來修飾波導的側壁，使其表面光滑以降低元件散射損失(scattering loss)。
電光調變器量測方面，透過不同偏壓的fabry-perot共振圖量測與phase retardation分析方法，耦入1515nm光源量測費比-普洛共振時，估算出C311在TE極化光源下的線性電光係數與二次電光係數分別為7.26×10-12m/v、1.14×10-18m2/v2；C251在TE極化光源下的線性電光係數與二次電光係數分別為2.99×10-11m/v、4.10×10-17m2/v2，在TM條件下電光調變特性主要受到Kerr效應影響，其值為3.52×10-17m2/v2，量測得到的電光係數與調變效率明顯的都比砷化鎵塊材(1.6×10-12m/v)與量子井提升許多，因此使用量子點材料設計低驅動電壓與小尺寸的調變器是具可行性的，未來可藉由增加腔長與減少主動層厚度提升相位與折射率的變化。

The purpose of this thesis is to fabricate the quantum dot waveguide and measure electro-optic (EO) modulation characteristics. We focus on the refractive index change (Δn), phase retardation, and electro-optic coefficients for quantum dot samples. The λg=1.3μm InGaAs quantum dot structures were grown on n+ GaAs substrates by MBE.
We design a series of 2.2μm straight and slope 7° single mode waveguide, and use the cleavage surface method to produce Fabry-Perot cavity. In fabrication process, we first defined the device pattern by using photo-lithography technique. Second, we etched ridge waveguide by using dry etching or multi-step wet etching method. Finally, we used the etching solution HBr:HCl:H2O2:H2O=5:4:1:70 to smooth the sidewall and reduce the scattering loss.
We analyzed the quantum dot EO properties by measuring phase retardation of Fabry-Perot resonance at different bias. From measuring the Fabry-Perot resonance atλ=1515nm TE-polarization, the linear electro-optic (LEO) and quadratic electro-optic (QEO) coefficients of C311 sample are 7.26×10-12m/v and 1.14×10-18m2/v2 , respectively. And the LEO and QEO coefficients of C251 sample are 2.99×10-11m/v and 4.10×10-17m2/v2, respectively. By coupling λ=1515nm TM-polarized light, we found the main influence of C251 sample is Kerr effect, and the QEO coefficient is 3.52×10-17m2/v2. Both electro-optic coefficients are significantly larger than those measured in quantum wells and bulk GaAs. These results are applicable to QD-based low drive voltage and small size modulators.

目 錄
第一章 簡介.............................................................................................1
1-1 前言.............................................................................................1
1-2電光調變器….….........................................................................3
1-3論文架構…..................................................................................4
第二章 半導體量子點光調變器..............................................................5
2-1 半導體材料.................................................................................5
2-2 電光效應.....................................................................................8
2-2-1 具電光效應之晶體.................................................................8
2-2-2 電光晶體材料的選擇...........................................................10
2-3 電光調變器...............................................................................11
2-4 光罩及元件之設計...................................................................15
2-5 元件模擬...................................................................................16
第三章 元件製程步驟............................................................................18
3-1 磊晶片資料...............................................................................18
3-2製程示意圖-乾蝕刻技術製作脊狀波導...................................21
3-3 乾蝕刻製程步驟.......................................................................28
3-4製程示意圖-濕蝕刻技術製作脊狀波導...................................36
3-5濕蝕刻製程步驟........................................................................40
第四章 量測方法與結果........................................................................44
4-1 量測系統介紹及驗證...............................................................44
4-2 耦合機制...................................................................................46
4-3 Fabry-Perot resonance method量測介紹..................................47
4-3-1 Fabry-Perot干涉現象.............................................................47
4-3-2 Fabry-Perot resonance損耗量測............................................48
4-4 Electro-optic properties量測分析.............................................49
4-5 量測結果...................................................................................51
4-5-1 樣品電性量測結果...............................................................51
4-5-2 量子點電光調變器量測結果...............................................52
第五章 結論............................................................................................64
參考文獻..................................................................................................65
附錄A 量子點磊晶片介紹....................................................................68
附錄B 量子點磊晶片PL光譜圖..........................................................69附錄C 量子點磊晶片由穿透吸收光譜以K-K transform得到的折射率
變化圖......................................................................................70













圖 目 錄
第一章
圖1-1 光通訊基本架構圖................................................................1
圖1-2 DWDM光通訊基本架構圖...................................................2
第二章
圖2-1(a) 塊材能態密度分佈圖.........................................................6
圖2-1(b) 量子井能態密度分佈圖.....................................................6
圖2-1(c) 量子線能態密度分佈圖.....................................................6
圖2-1(d) 量子點能態密度分佈圖.....................................................6
圖2-2 普通光線與異常光線圖.......................................................10
圖2-3 折射率橢圓圖.......................................................................11
圖2-4 縱向電光調制裝置圖...........................................................13
圖2-5 橫向電光調制裝置圖...........................................................14
圖2-6 脊狀波導第一道乾蝕刻元件定義光罩...............................15
圖2-7 脊狀波導第二道開窗口光罩...............................................15
圖2-8 脊狀波導第三道金屬電極光罩...........................................16
圖2-9 脊狀波導第四道濕蝕刻元件定義光罩...............................16
圖2-10(a) 模擬C311場圖...............................................................17
圖2-10(b) 模擬C311光強度與折射率分佈圖...............................17
圖2-11(a) 模擬C251場圖...............................................................17
圖2-11(b) 模擬C251光強度與折射率分佈圖...............................17
第三章
圖3-1 MBE_C311磊晶片結構圖.....................................................18
圖3-2 MBE_C311光激螢光(PL)頻譜圖.........................................19
圖3-3 MBE_C251磊晶片結構圖.....................................................19
圖3-4 MBE_C251光激螢光(PL)頻譜圖.........................................20
圖3-5 MBE_C251穿透式電子顯微鏡(TEM)影像圖......................20
圖3-6 光微影製程定義元件OM圖................................................29
圖3-7 ICP-RIE後波導側壁的SEM圖.............................................30
圖3-8 固化PI2562的升溫曲線.......................................................31
圖3-9 固化PI2556的升溫曲線.......................................................32
圖3-10 塗佈完PI2556的OM圖形.................................................32
圖3-11 開窗口後的OM圖形..........................................................33
圖3-12 定義金屬蒸鍍區域的OM圖形.........................................34
圖3-13 金屬掀離後OM圖形.........................................................35
圖3-14 金屬掀離後OM圖形.........................................................41
圖3-15(a) Multi-step蝕刻第一次SEM圖........................................43
圖3-15(b) Multi-step使用光阻填入undercut處SEM圖................43
第四章
圖4-1 系統完整架構圖...................................................................44
圖4-2 驗證量測系統模態結果2D圖............................................45
圖4-3 驗證量測系統模態結果3D圖............................................45
圖4-4 驗證量測系統收光效率頻譜圖...........................................46
圖4-5 驗證量測系統收光效率頻譜圖...........................................47
圖4-6 Fabry-Perot resonance量測架構圖.......................................48
圖4-7 Fabry-Perot resonance例圖....................................................49
圖4-8 C311、C251、C310、C382電壓-電流特性曲線................51
圖4-9 C311入射1480nm雷射光與不同逆向偏壓歸一化波導共振圖...52
圖4-10 C311入射1490nm雷射光與不同逆向偏壓歸一化波導共振圖...53
圖4-11 C311入射1500nm雷射光與不同逆向偏壓歸一化波導共振圖...54
圖4-12 C311入射1515nm雷射光與不同逆向偏壓歸一化波導共振圖...54
圖4-13 C311入射1525nm雷射光與不同逆向偏壓歸一化波導共振圖...55
圖4-14 C311入射1535nm雷射光與不同逆向偏壓歸一化波導共振圖...56
圖4-15 C311入射1545nm雷射光與不同逆向偏壓歸一化波導共振圖...56
圖4-16 C311入射1515nm@TM雷射光與不同逆向偏壓波導共振圖...57
圖4-17 C311不同入射光波長與不同偏壓之相位延遲圖………...57
圖4-18 C311不同入射光波長與不同偏壓之折射率變化圖……...58
圖4-19 C251入射1515nm@TE雷射光與不同逆向偏壓波導共振圖...59
圖4-20 C251入射1515nm@TM雷射光與不同逆向偏壓波導共振圖...59
圖4-21 C310入射1515nm@TE雷射光與不同逆向偏壓波導共振圖...60
圖4-22 C382入射1515nm@TE雷射光與不同逆向偏壓波導共振圖...60
圖4-23 C311@1515_TE相位延遲、折射係數變化與電光係數擬合圖...62
圖4-24 C311不同波長之電光係數圖........................................................62
圖4-25 C251@1515_TE相位延遲、折射係數變化與電光係數擬合圖...63
圖4-26 C251@1515_TM相位延遲、折射係數變化與電光係數擬合圖...63
圖4-27 C251@1515_TM相位延遲、折射係數變化與電光係數擬合圖...63
附錄A
圖一 C310磊晶片結構圖.............................................................................68
圖二 C382磊晶片結構圖.............................................................................68
附錄B
圖(a) C310磊晶片PL光譜圖....................................................................69
圖(b) C382磊晶片PL光譜圖....................................................................69
附錄C
圖(a) C251由穿透吸收光譜以K-K transform得到的折射率變化圖.....70
圖(b) C310由穿透吸收光譜以K-K transform得到的折射率變化圖.....70
圖(c) C382由穿透吸收光譜以K-K transform得到的折射率變化圖.....71








表 目 錄
第二章
表2-1 砷化鎵塊材與砷化銦、砷化銦鎵量子點電光係數表...........7
表2-2 砷化銦鎵/砷化銦鋁量子井TE極化電光係數表..................7
表2-3 砷化銦鎵/砷化銦鋁量子井TM極化電光係數表.................7
表2-4 C311、C251侷限因子..........................................................17
第三章
表3-1 ICP-RIE 乾蝕刻條件表........................................................30
第四章
表4-1 各樣品電阻值.......................................................................51
表4-2 C311 入射1480nm@TE雷射光不同偏壓相位偏移表.........53
表4-3 C311 入射1490nm@TE雷射光不同偏壓相位偏移表.........53
表4-4 C311 入射1500nm@TE雷射光不同偏壓相位偏移表.........54
表4-5 C311 入射1515nm@TE雷射光不同偏壓相位偏移表.........55
表4-6 C311 入射1525nm@TE雷射光不同偏壓相位偏移表.........55
表4-7 C311 入射1535nm@TE雷射光不同偏壓相位偏移表.........56
表4-8 C311 入射1545nm@TE雷射光不同偏壓相位偏移表.........57
表4-9 C251 入射1515nm@TE雷射光不同偏壓相位偏移表.........59
表4-10 C251 入射1515nm@TM雷射光不同偏壓相位偏移表......60
表4-11 樣品C311、C251 電光係數表..........................................62

[1] S. Kodama, T. Yoshimatsu, and H. Ito,“320Gbit/s optical gate monolithically integrating photodiode and electroabsorption modulator,” Electronics Letters, vol. 39, pp.383-385, Feb., 2003.

[2] H.-F. Chou, Y.-J. Chiu, A. Keating, J. E. Bowers, and D. J. Blumenthal , “Photocurrent-Assisted Wavelength (PAW) Conversion With Electrical Monitoring Capability Using a Traveling-Wave Electroabsorption Modulator,” IEEE Photon. Technol. Lett., vol. 16, pp.530-532, Feb., 2004.

[3] R. B. Welstand, S. A. Pappert, C. K. Sun, J. T. Zhu, Y. Z. Liu, and P. K. L. Yu, “Dual-function electroabsorption waveguide modulator /detector for optoelectronic transceiver applications,” IEEE Photon. Technol. Lett. 8, pp.1540–1542 ,1996.

[4] C. Y. Ngo, S. F. Yoon, W. K. Loke, Q. Cao, D. R. Lim, Vincent Wong, Y. K. Sim, and S. J. Chua, “Characteristics of 1.3μm InAs/InGaAs/GaAs quantum dot electroabsorption modulator,” Appl. Phys. Lett., vol.94, pp.143108, 2009.
[5] D. A. B. Miller, D. S. Chemla, T. C. Damer, A. C. Gossard, W. Weigmann, T. H. Wood, and C. A. Burrus, “Band-Edge Electroabsorption in Quantum Well Structures: The Quantum-Confined Stark Effect,” Phys. Rev. Lett., vol.53, pp.2173, 1984.
[6] S. Schmitt-Rink, D. A. B. Miller, and D. S. Chemla, “Theory of the linear and nonlinear optical properties of semiconductor microcrystallites,” Phys. Rev. B, vol.35, pp.8113, 1987.
[7] L. Davis, K. K. Ko, W.-Q. Li, H. C. Sun, Y. Lam, T. Brock, S. W. Pang, and P. Bhattacharya, “Photoluminescence and electro-optic properties of small (25–35 nm diameter) quantum boxes,” Appl. Phys. Lett., vol.62, pp.2766, 1993.
[8] O. Qasaimeh, K. Kamath, P. Bhattacharya, and J. Phillips, “Linear and quadratic electro-optic coefficients of self-organized In0.4Ga0.6As/GaAs quantum dots,” Appl. Phys. Lett., vol.72, pp.1275, 1998.
[9] S. Ghosh, A.S Lenihan, M.V.G Dutt, O Qasaimeh, D.G Steel, and P. Bhattacharya, “Nonlinear optical and electro-optic properties of InAs/GaAs self-organized quantum dots,” J. Vac. Sci. Technol. B, vol.19, pp.1455–1458, 2001.
[10] J. Tatebayashi, R. B. Laghumavarapu, N. Nuntawong, and D.L. Huffaker, “Measurement of electro-optic coefficients of 1.3 μm self-assembled InAs/GaAs quantum dots,” Electron. Lett., vol.43, pp.410-412, 2007.
[11] G. Moreau, A. Martinez, D.Y. Cong, K. Merghem, A. Miard, A. Lemaître, P. Voisin, A. Ramdane I. Krestnikov, A. R. Kovsh M. Fischer, and J. Koeth, “Enhanced In(Ga)As/GaAs quantum dot based electrooptic modulation at 1.55 μm,” Appl. Phys. Lett., vol.91, pp.91118, 2007.
[12] 葉東昆 撰, “1.55μm寬頻半導體光放大器研製與分析,”國立中山大學光電工程研究所碩士論文, 2004年6月。
[13] W.W. Chow, R.R. CRAIG, ”Amplified Spontaneous Emission Effects in Semiconductor Laser Amplifiers,” IEEE J. Quantum Electronics, Vol. 26, No. 8, Aug, 1990.
[14] Pallab Bhattacharya, ”Semiconductor optoelectronic devices,”Pearson Education, Apr., 2005.
[15] 陳政德 撰, “Fabrication and Measurement of Semiconductor Optical-Amplifiers and Ring Lasers,”國立中山大學光電所, 2006年6月。
[16] 林螢光 編著,“光電子學 : 原理、元件與應用,”全華科技,2000年。
[17] Kazuhisa Uomi, “Modulation-Doped Multi-Quantum Well (MD-MQW) Lasers. I. Theory,” Appl. Phys. Lett., Vol. 29, No. 1, pp. 91-87, 1990.
[18] Sang Sun Lee, Ramu V. Ramaswamy, and Veeravana S. Sundaram, “Analysis and Design of High-Speed High-Efficiency GaAs-AlGaAs Double-Heterostructure Waveguide Phase Modulator,” IEEE Journal of Quantum Electronics, Vol.27, No. 3, March , 1991.
[19] C.-A. Berseth, C. Wuethrich, and F. K. Reinhart, “The electro-optic coefficients of GaAs: Measurements at 1.32 and 1.52μm and study of their dispersion between 0.9 and 10μm,” J. Appl. Phys., Vol.71, No. 6, March, 1992.
[20] Shinji Nishimura, Hiroaki Inoue, Hirohisa Sano, and Koji Ishida, “Electrooptic Effects in an InGaAs/InAlAs Multiquantum Well Structure,” IEEE Photonics Technology Lett., Vol.4, No.10, October, 1992.
[21] U. Koren, T. L. Koch, H. Presting, and B. I. Miller, “InGaAs/InP multiple quantum well waveguide phase modulator,” Appl. Phys. Lett., Vol.50, No. 7, February, 1987.