本論文旨在研究應力緩衝多重量子點結構，樣品主要來源由實驗室分子束磊晶(MBE)機台成長，利用應力改變(metamorphic)以及AlAs作為緩衝保護層，以GaAs作為基板，成長出InGaAs的新基板，完成一系列長波長的多層InGaAs量子點結構。
實驗上我們利用調制反射光譜量測系統，分別用雷射光源以及脈衝(pulse)電壓，對樣品的介電常數進行調制，再從光調制反射光譜(Photoreflectance，PR) FKO圖形求得內建電場，以及電調制反射光譜(electroreflectance，ER) 求得各個能量躍遷的位置，另外我們再利用光激螢光、電致螢光、光電流以及電致吸收光譜圖加以分析比對。
由實驗結果發現，使用應力緩衝(Metamorphic)方法，利用晶格常數的差異長出In0.15Ga0.85As的新基板，所成長的量子點結構，發光波比傳統的以GaAs作為基板的量子點結構來的長，其發光波長可達到1460nm，成功的長出我們預期的長波長量子點結構，並在In0.15Ga0.85As buffer layer先長上一層3nm的GaAs之後，再長一層12nm的 In0.15Ga0.85As，會使磊晶面較為平整，再成長量子點結構會使得發光品質較佳。最後期望我們可以利用此方法設計出可達到1550nm的量子點結構。

Metamorphic multiple quantum dots (QDs) on GaAs substrates were grown by molecular beam epitaxy (MBE). The metamorphic layers including In0.15Ga0.85As and AlAs were in-situ annealed at high temperature (T=800oC) to reduce the dislocations. InGaAs QDs were then grown on the metamorphic layers.
We use the laser source and pulse voltage to modulate the dielectric constant of the samples in modulation reflectance measurement system. The inner electric field is obtained from the photo-reflectance Franz-Keldysh oscillation (FKO), and the energy transition is analyzed though the photoluminescence (PL), electroluminescence (EL), and photocurrent (PC) spectroscopy.
The electroluminescence wavelength of InAs QDs on metamorphic In0.15Ga0.85As substrate can be push to ~1460 nm. The optimum emission quality is obtained by inserting 3-nm GaAs layer beneath the In0.15Ga0.85As buffer layer. The In0.15Ga0.85As buffer is flatter because of the GaAs layer, and the QDs become more uniform. We expect the InAs QDs on metamorphic GaAs substrate can be applied for optical communication in the λ=1550 nm region.

第一章 緒論 .........................................................................1
1-1 前言..............................................................................1
1-2 內容架構......................................................................1
第二章 實驗樣品介紹.........................................................2
2-1 應力緩衝(Metamorphic)結構之基板設計................2
2-2 應力緩衝(Metamorphic)量子點結構........................3
第三章 實驗方法與製程步驟..............................................8
3-1 光激螢光量測...............................................................8
3-2 光調制反射光譜量測.................................................10
3-3 直流偏壓光調制反射光譜量測.................................11
3-4 電調制反射光譜量測.................................................12
3-5 電激螢光量測.............................................................13
3-6 光電流量測.................................................................14
3-7 電致吸收量測.............................................................16
3-8 量測元件mesa製程步驟..........................................18
第四章 實驗結果與分析..................................................27
4-1 螢光光譜比較與分析.................................................27
4-2 調制反射光譜量測圖與分析.....................................36
第五章 結論.....................................................................57
參考文獻.............................................................................59

[1] Z.Mi, P.Bhattacharya and J.Yang “Growth and characteristics of ultralow threshold 1.45 μm metamorphic InAs tunnel injection quantum dot lasers on GaAs.” Applied Physics Letters 89, 153109 (2006)
[2] Z. Mi, C. Wu, J. Yang,and P.Bhattacharya “Molecular beam epitaxial growth and characteristics of 1.52 μm metamorphic InAs quantum dot lasers on GaAs.” J. Vac. Sci. Technol. B, Vol. 26, No. 3 (2008)
[3] G. L. Rowland and T. J. C. Hosea , S. Malik, D. Childs, and R. Murray “A photomodulated reflectance study of InAs/GaAs self-assembled quantum dots.” Applied Physics Letters Volume 73, NumberU 22 (1998)
[4] C. M. Lai, F. Y. Chang, C. W. Chang, C. H. Kao, H.H. Lin, and G. J. Jan “Temperature dependence of photoreflectance in InAs/GaAs quantum dots.” Applied Physics Letters Volume 82, Number 22 (2003)
[5] P.Bhattacharya, Z.Mi, J.Yang , D.Basu, D.Saha, “Quantum dot lasers:From promise tohigh-performance devices.”J.Crystal Growth (2008)
[6] 簡茹吟“砷化鎵半導體的光調制光譜的調制場效應” 國立中山大學物理研究所，2000
[7] 許世祿 “垂直耤合自聚性砷化銦鎵量子點之光學特性研究” 國立中央大學物理研究所，2000
[8] 黃雍倫 “寬波段量子點結構之光學特性研究” 國立中山大學光電工程研究所，2007
[9] 梁家輔 ”非對稱多重量子井結構之光學特性研究” 國立中山大學光電工程研究所，2006
[10] 丁紀仁“以光調制反射光譜探測半導體內建電場及調制場效應研究” 國立中山大學光電工程研究所，2005