臺灣博碩士論文加值系統

我們利用已校正之分子束磊晶系統中具有應變的組成，設計並成長三元與四元應變之多重量子井結構。在0.98□m波長的In0.18Ga0.82As/GaAs多重量子井結構中，經過量測光激螢光光譜結果發現，主要螢光峰值出現在0.967□m，同時在0.953□m有次螢光峰出現，我們推測可能由於在成長過程中，銦在磊晶層分布不均勻所致。光電流光譜量測結果顯示，對TE極化光，在波長0.98□m處有一階梯型吸收邊，而對TM極化光則無明顯的吸收邊出現；我們根據光激螢光光譜之主峰值修正量子井實際磊晶厚度後，可以得到hh1→e1之吸收與TE吸收邊量測結果相吻合，而此模擬結果亦顯示在0.95□m處有電洞Continuum能帶至e1次能帶之吸收，此三維至二維次能帶躍遷，可解釋在光電流光譜中TM之寬廣吸收邊係由類似bandtail與Franz-Keldysh效應所引起。
在1.55□m波長的InGaAs/InGaAlAs的多重量子井結構中，我們則是利用伸張應變量子井，在量子井內部加入二層厚度各異之晶格匹配InGaAs層，並形成多層式量子井結構，由於量子井內躍遷的特性會隨著重電洞與輕電洞物質波波長不同而異，可達到極化不敏感特性的設計。經由光激螢光光譜與光電流光譜的量測結果發現，在1.55□m波長附近，無論偏壓與否， TE與TM極化光之吸收邊分布的位置幾乎相同，此與理論模擬結果相當的吻合，這也說明了本實驗所成長之磊晶層能夠滿足原先設計之極化不敏感特性的要求。

The work of this thesis includes molecular beam epitaxy (MBE) and optical study of strained InGaAs and InGaAlAs multiple quamtum well (MQW) structures. Two strained layer structures suitable for devices applications have been designed, grown, and investigated.
The first one is a 0.98-□m In0.18Ga0.82As/GaAs MQW structure. The room temperature PL spectrum shows a main peak at □ = 0.967□m, and a secondary peak at □ = 0.953□m. The possible reason is the In segregation during growth by the lower substrate temperature at 470℃. Therefore, the quantum well width and In composition are smaller than the expected value. For TE photocurrent measurement, a step-like absorption edge shows near □ = 0.98□m, while for the TM case, no obvious absorption edge has been observed. From the well width obtained by fitting the PL main peak, the calculated hh1-e1 subband transition is consistent with the TE absorption. The simulation also shows a hole continuum state to e1 subband transition at □ = 0.95□m. The broaden TM photoabsorption edge can be explained by the 3D state to 2D subband transition including bandtail and Franz-Keldysh effects.
The second one is a strain balanced InGaAs/InGaAlAs QW structure on InP designed to be polarization insensitive at 1.55 □m. The PL and TE and TM photocurrent spectra are in reasonably good agreement with the results of theoretical simulation. The latter indicate a polarization insensitivity that is nearly independent of the applied bias.

第一章 導論 1
1-1 前言 1
1-2 論文架構 4
第二章 實驗原理 5
2-1 應變的產生 5
2-2 晶格常數與能隙關係 10
2-3 能隙理論 12
2-4 量子侷限史塔克效應（QCSE） 16
2-5 極化方向不敏感 17
2-6 元件的應用 19
2-6-1 電制吸收調變器 19
2-6-2 半導體光放大器 20
2-7 結構設計與理論模擬 21
2-8 極化不敏感之單量子井結構設計範例 23
第三章 實驗系統 28
3-1 分子束磊晶系統 28
3-1-1 分子束磊晶機台 31
3-2 量測系統簡介 33
3-3 光激螢光光譜（PL）實驗裝置 36
3-4 光電流光譜（Photo current）實驗裝置 39
第四章 實驗方法 43
4-1 晶格匹配與材料組成 43
4-2 應變型磊晶結構的設計 45
4-3 InGaAs/GaAs 壓縮應變型多重量子井結構 46
4-4 InGaAlAs/InP 伸張應變型多重量子井結構 51
第五章 實驗結果與分析 57
5-1 應變型材料系統 57
5-2 InGaAs/GaAs多重量子井結構 59
5-3 InGaAlAs/InP多重量子井結構 67
第六章 結論 72
參考文獻 74
附錄A APPPRARA 程式說明 77
附錄B QCSEOIWF 程式說明 78
附錄C 內建電場的求法 79
附錄D 實驗製程步驟 81
D-1 GaAs 基板清洗與基板溫度校準步驟 81
D-2 InP 基板清洗與基板溫度校準步驟 82
D-3 量測前製程步驟 84

[1]J. M. Kuo et al., Semiconductor-Based Heterostructures, pp. 175-184, The Metallurgical Society, Inc. [2]A. Godefroy, A. Le Corre, and F. Clérot, “In1-xGaxAs/In0.53Ga0.47As strained superlattices grown by gas source molecular beam epitaxy,” Indium Phosphide and Related Materials, 1993. Conference Proceedings, pp. 143-146, 1993. [3]G. P. Agrawal and N. K. Dutta, Semiconductor Laser, 2nd ed., pp. 15-21,American Institute of Physics. [4]Y. Chen, J. E. Zucker, N. J. Sauer, and T. Y. Chang, “Polarization-independent strained InGaAs / InGaAlAs quantum-well phase modulators, ” IEEE Photon. Technol. Lett., vol. 4, pp. 1120-1123, 1992.[5]H. Q. Hou, and T. Y. Chang, “Nearly chirp-free electroabsorption modulation using InGaAs-InGaAlAs-InAlAs coupled quantum wells,” IEEE Photon. Technol. Lett., vol. 7, pp. 167-169, 1995.[6]A. Ougazzaden, and F. Devaux, “Strained InGaAsP/InGaAsP/InAsP multi-quantum well Structure for polarization insensitive electroabsorption modulator with high power saturation,” Appl. Phys. Lett., vol. 69, pp. 4131-4132, 1996.[7]J. S. Osinski, Y. Zou, and P. Grodzinski, “Low-threshold-current-density 1.5□m lasers using compressively strained InGaAsP Quantum Wells,” IEEE Photon. Technol. Lett., vol. 4, pp. 10-13, 1992.[8]A. Ougazzaden, D. Sigogne, and A. Mircea, “Atmospheric pressure MOVPE growth of high performance polarization insensitive strain compensated MQW InGaAsP/InGaAs optical amplifier,” Electronics Lett.,vol. 31, pp. 1242-1244, 1995.[9]Mark Silver, A. F. Phillips, and A. R. Adams, “Design and ASE characteristics of 1550-nm polarization-insensitive semiconductor optical amplifiers containing tensile and compressive wells,” IEEE Journal of Quantum Electronic, vol. 36, pp. 118-122, 2000.[10]L. F. Tiemeijer, P. J. A. Thijs, and T. van Dongen, “Polarization insensitive multiple quantum well laser amplifiers for the 1300 nm window,” Appl. Phys. Lett., vol. 62, pp. 826-828, 1993.[11]A. Godefroy, A. Le Corre, and F. Clérot, “1.55-□m polarization-insensitive optical amplifier with strain-balanced superlattice active layer, ” IEEE Photon. Technol. Lett., vol. 7, pp. 473-475, 1995.[12]M. A. Newkirk, B. I. Miller, and U. Koren, “1.55 □m multiquantum-well semiconductor optical amplifier with tensile and compressively strained wells for polarization-independent gain, ” IEEE Photon. Technol. Lett., vol. 4, pp. 406-408, 1993.[13]Katsuaki Magari, and Minoru Okamoto, “1.55 □m polarization-insensitive high-gain tensile-strained-barrier MQW optical amplifier, IEEE Trans. Photon. Technol. Lett., vol. 3, pp. 998-1000, 1991.[14]Katsuaki Magari, and Minoru Okamoto, “Polarization-insensitive optical amplifier with tensile-strained-barrier MQW structure, ” IEEE Journal of Quantum Electronic, vol. 30, pp. 695-701, 1994.[15]Jasprit Singh, Semiconductor optoelectronics, pp. 28-32, McGraw-Hill, Inc. [16]J. W. Matthews, and A. E. Blakeslee, “Defects in epitaxial multilayers,” J. Cryst. Growth, vol. 27, pp. 118-125, 1974.[17]H. Temkin, D. G. Gershoni, and S. N. G. Chu, “Critical layer thickness in strained Ga1-xInxAs/InP quantum wells,” Appl. Phys. Lett., vol. 55, pp. 1668-1670, 1989.[18]Pallab Bhattacharya, Semiconductor Optoelectronic Devices, 2nd ed. pp. 137, Prentice Hall International Editions.[19]C. Y—P Chao, and S. L. Chuang, “Spin-orbit-coupling effects on the valence-band structure of strained semiconductor quantum wells,” Phys. Rev. B, vol. 46, pp.4110-4122, 1992.[20]S. L. Chuang, Physics of optoelectronic devices, pp.707-711, A Wiley-Interscience Publication, New York. [21]Alex Harwit, and J. S. Harris, Jr, “Calculated quasi-eigenstates and quasi-eigenenergies of quantum well superlattices in an applied electric field,” Appl. Phys. Lett., vol. 60, pp. 3211-3213, 1986.[22]T. Y. Chang and A. Izabelle, “Full range analytic approximations for Fermi energy and Fermi-Dirac integral F-1/2 in terms of F1/2,” J. Appl. Phys., vol. 65, pp. 2162-2164, 1989.