電致吸收光調變器(EAM)在光電積體電路中扮演著極為重要的角色。InGaAs/InAlAs是一種製造1.55μm EAM絕佳之材料，因為其較強之激子效應(exciton effect)和優良之能帶結構故能產生較高之飽和操作功率。
本論文一開始著重於InGaAlAs量子井之理論計算，利用Vegard’s law 去求得上述四元材料之一些物理參數,如等效質量、晶格常數,應力常數等。並利用共振散射法 (Resonant Scattering Method) 去計算量子井的能階和波函數重疊積分。藉此得以計算出光增益(optical gain)和光吸收(optical absorption)。
本文亦製作出InGaAlAs為主之電致光吸收調變器，以與理論相比較。為了使達高速之操作，本工作亦發展出底切蝕刻主動層之技術，利用citric acid對InGaAs與InAlAs之選擇性蝕刻可縮小主動層之寬度，以達成小寄生電容。其元件製程方面，約略可分為下列幾個步驟: 1) 使用濕式蝕刻，蝕刻出脊狀波導與主動層底切蝕刻﹔2)利用熱蒸鍍機蒸鍍n型接觸金屬和熱回火﹔3)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﹔4)最後再鍍電極、建構切割線、研磨晶圓、切割元件。

The electroabsorption modulators (EAM) play an important role in the optoelectronic integrated circuits. InGaAs/InAlAs is an excellent material system for fabricating 1.55-μm EA modulators. Natural high band-offset ( ) ratio structure and the strong exciton effect make this kind of material a good candidate for high saturation power operation and high speed.
In order to design good quantum-well (QW) for electroabsorption, the Vegard’s law is used to obtain the parameters of In1-x-yGaxAlyAs material by interpolating the relevant binary semiconductor material. The bowling factor is included in finding the right bandgap. Using the Resonant Scattering Method, the QW energy levels and electron-hole overlap integrals can be obtained to calculate the optical electroabsorption effects.
In this thesis, the TWEAM based on In1-x-yGaxAlyAs material is also fabricated. In order to get low parasitic capacitance for high-speed operation, a processing called undercut-etching the active region is developed in this work. A selective etching solution (citric acid : H2O2) is used to etch InGaAs layers from InAlAs and the undercut-etching structure InGaAlAs EAM has been successfully fabricated. The processing includes 1)optical waveguide formation with wet etching; 2)n-contact evaporation and contact annealing; 3)mesa etch, PMGI passivation/bridging/planarization; 4)final metallization, cleaving line formation, wafer lapping and device cleaving.

第一章 序論……………………………………………………………1
1-1 前言……………………………………………………….1
1-2 電致吸收光調變器的製作、特性以及優點.....................1
1-3 In1-x-yGaxAlyAs材料系統相對於In1-xGaxAsyP1-y材料系統之優缺點比較……………………………………………...2
1-4 電致吸收光調變器的應用……………………………….3
1-5 論文架構………………………………………………….3

第二章 光波導材料結構的設計……………........................................4
2-1 量子侷限史塔克效應(Quantum Confined Stark Effect ,QCSE).……………………………………........4
2-2 以共振散射法(Resonant Scattering Method)計算量子井能階….……………….……………………………………7
2-3 In1-xGaxAsyP1-y 和 In1-x-yGaxAlyAs 量子井設計………...12
2-4 吸收係數之計算與設計實例…………………………..18
2-5 針狀(spiked)和非針狀(non-spiked)量子井設計…..19

第三章 InGaAs/InAlAs元件製作…………………………………...23

3-1 材料結構………………………………………………23
3-2 TEAMs元件製程步驟………………………………….25
3.3 元件完成………………………………………………51

第四章 量測結果……………………………………………………..54
4-1 基本電性量測…………………………………………...54
4-2 微波特性量測…………………………………………...55


第五章 結論…………………………………………………………..58

參考文獻………………………………………………………….…..59

附錄一………………………………………………….……………..60

[1] S. Zhang, “Traveling-wave Electroabsorption Modulators,
” University of California, Santa Barbara, CA, Ph.D. Dissertation,1999.
[2] S. L. Chuang, Physics of Optoelectronic Devices, John Wiley &
Sons, Inc, 1995.
[3] J. Minch, S. H. Park, T. Keating, and S. L. Chuang, Fellow, IEEE,“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 5 (2000) 215-273, 1999.
[5] L. A. Coldren and S. W. Corzine, Diode lasers and photonic integrated circuits,
John Wiley & Sons, Inc., New York, pp. 527-536, 1995.
[6] H. Kroemer, Quantum Mechanics: For Engineering, Materials Science, and Applied Physics, Prentice Hall (1994), chapter 5.
[7] D. A. B. Miller, D. S. Chemla, T. C. Damen, A. C. Gossard, W. Wiegmann, T. H. Wood, and C. A. Burrus, “Electric field dependence of optical absorption near the band gap of quantum-well structures,” Phys. Rev. B, Condens. Matter, vol. 32, pp. 1043-1060, 1985.