本論文主旨在於藉由光學量測來探討InAs自組織而成的量子點結構與InAs/GaAsN數位合金結構的特性。並且經由RTA回火去觀察樣品受回火溫度影響的情形。
研究的樣品結構分別為InGaAs/InAs、InGaAs/InAlAs/InAs、InGaAs/AlAs/InAs量子點結構以及InAs/GaAsN量子井結構等材料。InAs量子點結構實驗樣品有幾種不同的覆蓋層，經實驗觀察可見含有Al的結構可拉遠基態和激發態間距。這又與其所含Al那層的位能障厚度與比例有關，當Al含量較多時(即InAlAs/InAs) 基態和激發態間距可達123meV，但是這又使得發光強度比起只覆蓋InGaAs來說減少了近3倍的強度。當經由回火實驗後量測觀察，含Al的結構受到回火的影響較少。
在InAs/GaAsN數位合金結構，透過變溫PL和回火的實驗來作分析。從變溫的光激螢光光譜觀察到與InGaAsN量子井類似會在低溫下出現S型的變化(S-shaped)，但樣品中特別的結構觀察到對『溫度不敏感』的情形，其S型的變化並不明顯。推測由於應力不同可能造成對溫度敏感度不同。

The purpose of this thesis is to study the InAs self-organized quantum dots and InAs/GaAsN digital alloys. We have studied the optical properties of these structures after rapid thermal annealing. The measured samples are InGaAs/InAs、InGaAs/InAlAs/InAs、InGaAs/AlAs/InAs quantum dots and InAs/GaAsN short-period superlattice quantum well structures. We have investigated the effect of different strain-reducing layer (SRL) on the photoluminescence (PL) of self-assembled InAs/GaAs quantum dots. From experiments, the coverage layers of Al composition can increase the energy splitting between the ground and first excited states of the quantum dots. It is related to the thickness and composition of the cap layers. Using thick InAlAs and InGaAs together as a SRL results in the energy splitting up to 123meV. However the PL intensity decreases three times. After rapid thermal annealing up to 800°C, the QDs with Al-composed cap layer show no shift of peak wavelength.
For InAs/GaAsN digital alloys, through temperature dependent PL spectrum, we can observe PL peak has a blue shift form room temperature to 100K, and a red shift from 100K to 10K. It is similar to the InGaAsN quantum well. However, one of the samples shows temperature insensitive for the PL peaks.

目 錄

頁次
摘要
目錄 ……………………………………………..…………………………….1
第一章　緒論 ……………………………………………………………...…2
1•1 前言 2
1•2 研究動機與目的 2
1•3 內容架構 3
第二章 半導體奈米量子結構 ……………………………………………...4
2•1 InGaAs/InAs 量子點結構 4
2•2 InGaAs/InAlAs/InAs 量子點結構 5
2•3 InGaAsN量子井結構 6
2•4 InAs/GaAsN數位合金結構 8
第三章 實驗方法與製程步驟 …………………………………………...9
3•1 光激螢光量測 9
3•2 光電流量測 12
3•3 電制吸收量測 14
3•4 量測元件製成步驟 16
第四章 實驗結果與分析 …………………………………………….......21
4•1 光激螢光量測和變溫光激螢光量測測結果與分析 21
4•1-1 量子點結構樣品 21
4•1-2 數位合金結構樣品 47
4•2 光電流與電制吸收量測結果與分析 60
第五章 結論 ……………………………………………………….........68

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