臺灣博碩士論文加值系統

在光纖通訊系統中，為達到高速高輸出之光調變訊號，半導體電致光調變器與光放大器為重要的元件，因其材料特性相似可由製程與長晶方式來達成整合，以降低成本並提高特性。在本文中我們提出一新穎之結構以達成高頻高光輸出功率之放大器與調變器的整合，名為串疊式方法整合光放大器與電致光吸收調變器，元件整合在單一晶塊，而在元件的主動層材料上，我們選擇InGaAsP/InGaAlAs 材料系統來增加band offset，以提高電子的侷限能力，進而達到高增益，高調變現象；同時由於串疊方式，可將高阻抗之微帶線與低阻抗之調變器整合，來降低阻抗之不匹配；所以此法可同時提升元件電與光之傳輸。
光波導是利用底切蝕刻形成，對InGaAsP與InGAAlAs之選擇性蝕刻可縮小主動層之寬度，以達成小寄生電容且有平滑之波導側面，以提高光與微波之傳輸；元件製程上，約略可分為下列幾個步驟:(1)使用離子佈植，來做EAM逆偏壓和SOA順偏壓之間isolation(隔離層)以降低電壓; (2) 使用濕式蝕刻，蝕刻出脊狀波導與主動層底切蝕刻﹔(3)利用電子束蒸鍍機蒸鍍n型、P型接觸金屬和熱回火﹔(4)斜坡蝕刻，使用高分子材料PMGI來做保護膜，平坦化及繞線橋樑之用﹔(5)最後再鍍電極、建構切割線、研磨晶圓、切割元件;( 6)元件的量測和分析。
本工作中已成功製作出InGaAsP/InGaAlAs為主之SOA及EAM的整合元件，經由量測，相對於單一調變器，電性頻寬已提升10GHz，光的增益大於5dB，在１伏特操作偏壓與光波長1568nm下，調變效率可達11dB/V。

Semiconductor optical amplifiers (SOA) and electroabsorption modulators (EAM) have been become vital elements to obtain high-output-power and high-speed optical signal in the optical fiber communications. In this paper, we propose a novel type cascaded integrated SOAs and EAMs, which are monolithically integrated in the same chip without any regrowth. In the active region, high electron bandgap offset material, InGaAsP/InAlGaAs, is used in order to get high optical gain and also high modulation. Using cascaded SOAs and EAMs, high impedance of microwave stripe lines are the bridges connecting the small EAM elements, bring up higher impedance and thus enhancing the microwave transmission.
The optical waveguide is made by selectively undercut etching InGaAsP/InAlGaAs material in order to reduce the optical scattering loss and also the microwave loss due to the low parasitic capacitance. The processing is described by the following steps: (1) ion implantation to get electrical isolation; (2) wet etching to form the optical waveguide ridge; (3) e-gun evaporation to get n- and p- metalization ; (4) spinning PMGI as planarization; (5)Final thick metalizations as for microwave transmission line.
The final integrated cascaded SOAs and EAMs has been successfully fabricated and measured. In comparison with single EAM, higher than 10GHz of –3dB electrical transmission has been found, indicating the cascaded integration structure has better impedance matching and also higher electrical transmission. The measured optical gain is higher than 5dB with 11dB/V modulation efficiency at excitation wavelength of 1568nm.

目錄
中文摘要……………………………………………………………Ⅱ
英文摘要……………………………………………………………Ⅳ
誌謝…………………………………………………………………Ⅴ
目錄…………………………………………………………………Ⅵ
第一章 序論……………………………………………………………………1
1-1 前言……………………………………………………………1
1-2 研究動機………………………………………………………1
1-3 論文架構………………………………………………………3
第二章 理論………………………………………………………4
2-1光電半導體……………………………………………………4
2-2吸收與放大係數………………………………………………5
2-3量子侷限史塔克效應（Q.C.S.E.）…………………………11
2-4降低端面反射率的元件結構……………………………13
第三章 光波導材料結構設計……………………………………15
3.1 晶格形變材料之量子井定義…………………………15
3.1.1 計算晶格形變後之能隙…………………………………15
3.1.2 計算能帶補償…………………………………20
3.2 量子井基態能階與波函數計算………………………22
3.3 非對稱針狀位能勢量子井……………………………24
3.4 光傳輸係數與模擬……………………………………26
第四章 材料磊晶結構與元件製程…………………………30
4-1材料磊晶結構………………………………………………30
4-2元件製程……………………………………………………33
4-3 結論………………………………………………………42
第五章 元件特性量測與討論 ………………………………43
5-1 金半接觸電阻 …………………………………………43
5-2 微波訊號S 參數……………………………………45
5-3 SOA光譜量測……………………………………………48
5-4光波導傳輸係數…………………………………………50
5-5問題與結果討論…………………………………………51
第六章 結論…………………………………………………53
第七章 參考文獻…………………………………………55

[1] S. L. Chuang, “Physics of Optoelectronic Devices,” John Wiley & Sons, Inc,1995.
[2] G. P. Agrawal, N. K. Dutta, Semiconductor Laser, 2nd ed., Van Nostrand Reinhold, New York, 1993
[3] J. Minch, S. H. Park, T. Keating, and S. L. Chuang, “Theory and Experiment of In1-xGaxAsyP1-y and In1-x-yGaxAlyAs Long-Wavelength Strained Quantum-Well Lasers,” IEEE Journal of Quantum Electronics, Vol.35, No.5,May 1999.
[4] E.Herbert Li, “Material parameters of InGaAsP and InAlGaAs systems for use in quantum well structures at low and room temperatures,” Physica E:Low-dimensional Systems and Nanostructures, Volume 5, Issue 4, 1 March
2000, Pages 215-27
[5] H. Kroemer, “Quantum Mechanics: For Engineering, Materials Science, and Applied Physics, ” Prentice Hall, 1994
[6] F. Devaux, J. C. Harmand, I. F. L. Dias, T. Giettler, O. Krebs and P. Voisin,“High Power Saturation, Polarization Insensitive Electro-
absorption Modulator with Spiked Shallow Wells,” Electronics Letters, Vol.33, No.2,1997
[7] 李政鍵 ,”Unsymmetry Spiked-Quantum Well Design and Electro- absorption Modulators Based on the InAlAs/InGaAlAs Material System”2004
[8] Robert Lewén, Member, IEEE, Stefan Irmscher, Urban Westergren, Member, IEEE,Lars Thylén, Member, IEEE, Member, OSA, and Urban Eriksson
“Segmented Transmission-Line Electroabsorption Modulators” “2004”
[9] 李典融, “Fabrication of InGaAsP/InGaAsP Electroabsorption Modulator by Wet Etching,” National Sun Yat-sen University, Institute of Electro-Optical Engineering, 2003
[10] 李錦堂, “Quantum Well Design and Electroabsorption Modulators
Fabrication Based on the InGaAs/InAlAs material system,” National Sun
Yat-sen University, Institute of Electro-Optical Engineering, 2003
[11] R. E. Williams, “Gallium Arsenide Processing Techniques”
[12] G. L. Li, C. K. Sun, S. A. Pappert, W. X. Chen and P. K. L. Yu,
“Ultrahigh-Speed Traveling-Wave Electroabsorption Modulator—Design and Analysis,” IEEE Trans. Microwave Theory Technol., Vol.47, pp.1177–1183,1999

[13] Bing Xiong, Jian Wang, Lijiang Zhang, Jianbai Tian, Changzheng Sun, and Yi Luo“ High-Speed (>40 GHz) Integrated Electroabsorption Modulator Based on Identical Epitaxial Layer Approach”2005
[14] G. Bastard, E. E. Mendez, L. L. Chang, and L. Esaki, “ Variational calculations on a quantum well in an electric field,” Phys. Rev. B, Condens. Matter, vol. 28, pp. 3241-3245, 1983.
[15] S. Nojima and K. Wakita, “ Optimization of quantum well materials and structures for excitonic electroabsorption effects,” Appl. Phys. Lett., vol. 53, pp. 1958-1960, 1988.
[16] Byeong Hoon Park, In Kim, Member, “Investigation of Optical Feedback in High-Speed Electroabsorption Modulated Lasers With a Window Region” 2005
[17] In Kim,Membe,” Design of Amplifier- and Modulator-Integrated Laser
Diode for 10-Gb/s 80-km Transmission” IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, VOL. 11, NO. 2, MARCH/APRIL 2005
[18] DIETRICH MARCUSE,” Reflection Loss of Laser Mode From Tilted End
Mirror” JOURNAL OF LIGHTWAVE TECHNOLOGY. VOL. 1. NO. 2. FEBRUARY 1989
[19] S.G.MENOCAL”1.5um GaInAsP Angled-Facet Flared-Waveguide Traveling
Wave laser Amplifiers”IEEE PHOTONICS TECHNOLOGY LETTERS.VOL. 2 . NO.1 JANUARY1990
[20] M. Linnik, A. Christou,” Calculations of optical properties for quaternary III–V semiconductor alloys in the transparent region and
above (0.2–4.0 eV)” Department of Materials and Nuclear Engineering and Materials Research Science and Engineering Center, University of Maryland,College Park, MD 20742, USA Received 26 November 2001; accepted 5 December 2001
[21] Zheng Wang, Benny Mikkelsen, Bo Pedersen, Kristian E.” Coupling Between Angled-Facet Amplifiers and Tapered Lens-Ended Fibers” JOURNAL OF LIGHTWAVE TECHNOLOGY. VOL. 9. NO. I . JANUARY 1991