臺灣博碩士論文加值系統

本論文研究目的是使用分子束磊晶(MBE)機台，以S-K模式在Ⅲ-Ｖ族磊晶片(GaAs)上成長雷射結構，我們成長12層InxGa1-xAs量子點綴於(In0.1Ga0.9As)量子井結構，藉由改變不同的磊晶參數以及製程條件，來達到雷射表現的最佳化。本研究中以一系列量子點綴於井雷射結構來做分析，是因為量子點綴於井結構相較於量子點結構雷射而言，更能在主動層內有效增加載子的捕獲率。磊晶條件方面，將量子井中有無P型摻雜(Be)，並改變不同的量子井成長溫度來作比較。
雷射製程方面則以乾式蝕刻的方式來製作脊狀波導，波導寬度約為2.2mm，利用脊狀波導及兩端鏡面-自然劈裂面(無抗反射塗層)產生Fabry-Perot雷射。相較於濕式蝕刻，乾式蝕刻更能將圖形有效地由光罩轉移至樣品表面上，且能解決濕蝕刻所產生的側蝕問題。
最後雷射元件量測部分，P-type doping雷射最大發光強度(單邊)可達到24mW，發光效率為0.209W/A，而改變成長溫度至580 oC後，PWell580雷射最大發光強度(單邊)可達到26 mW，發光效率更往上提升至0.238W/A。

The purpose of this thesis is to fabricate 12-layer InxGa1-xAs quantum dots grown on 2-nm In0.1Ga0.9As quantum wells (DWell) laser structures grown by molecular-beam epitaxy (MBE) on GaAs substrats. We expect to optimum the lasers performance by tune the epitaxial recipe and fabrication condition. For the carrier injection efficiency, DWell structure of quantum dots grown on quantum wells is proposed to enhance the carrier capture rate. So we analyze a series of DWell structure in this work. In the epitaxial recipe, we investigate the influences of p-type doping and change the quantum wells growth temperature for the laser structures.
In the laser fabrication, to transport the light wave in smaller dispersion loss single mode waveguide, dry etching photolithography processes are adapted in this study to fabricate 2.2mm width ridge waveguide. The as-cleaved facets are used as Fabry-Perot laser mirrors in ridge waveguide lasers. The pattern can be transferred effectively with less under-cut by dry etching compare with wet etching.
Finally, the P-type doping DWell laser exhibits high power/facet of 24mW, slope efficiency of 0.209W/A. The maximum power/facet of PWell580 laser reach to 24mW, slope efficiency of 0.238W/A after raising the growth temperature to 580oC.

目 錄

頁次
論文審定書.... ii
誌謝.... iv
中文摘要....v
英文摘要....vi
第一章 簡介....1
1-1 前言....1
1-2 量子點雷射....2
1-3 雷射材料的選擇....3
1-4 論文架構....4
第二章 量子點雷射工作原理....5
2-1 雷射原理....5
2-1-1 電磁輻射與物質作用的躍遷....6
2-1-2 居量反置....7
2-1-3 共振腔與臨界增益....7
2-2 摻雜對半導體產生的效應與影響....9
2-3 光罩元件設計....10
第三章 元件結構與製程步驟....12
3-1 磊晶片資料....12
3-2 製程示意圖-乾蝕刻技術製作脊狀波導....16
3-3 乾蝕刻製程步驟....23
第四章 量測結果與數據分析....29
4-1 量測系統介紹及驗證....29
4-2 Fabry-Perot 量測介紹....32
4-2-1 Fabry-Perot共振條件....32
4-2-2 量子效率計算(Quantum efficiency)....33
4-2-3 Hakki Paoli method量測方法介紹....34
4-3 L-I&OSA量測方法介紹....35
4-4 量子點綴於井結構雷射量測結果....36
4-4-1 雷射電性量測....36
4-4-2 雷射L-I與頻譜(OSA)量測圖....41
4-4-3 量測整理與數據計算分析....49
第五章 結論....54
參考文獻....55
圖 目 錄

頁次
圖1-1 不同主動層雷射結構其載子能量對能態密度分佈圖 ....3
圖2-1 雷射光學共振腔模型 ....5
圖2-2 電磁輻射放射機制圖 ....6
圖2-3 Fabry-Perot共振腔示意圖....9
圖2-4 未修改前P-metal圖形....11
圖2-5 脊狀波導第一道乾蝕刻元件定義光罩....11
圖2-6 脊狀波導第二道定義金屬電極光罩....11
圖3-1 Undoped DWell Laser(C576) 磊晶片結構圖 ....12
圖3-2 Undoped DWell Laser(C576)光激螢光(PL)頻譜圖 ....3
圖3-3 P-type doping DWell Laser(C540)磊晶片結構圖 ....13
圖3-4 P-type doping DWell Laser(C540)光激螢光(PL)頻譜圖....14
圖3-5 P-type doping DWell580 Laser(C600)光激螢光(PL)頻譜圖....14
圖3-6 P-type doping DWell560 Laser(C602)光激螢光(PL)頻譜圖....15
圖3-7 光微影製程定義ridge pattern....24
圖3-8 ICP-RIE蝕刻完再經酸修飾後波導側壁SEM圖 ....25
圖3-9 RIE蝕刻前....26
圖3-10 RIE蝕刻後....26
圖3-11 定義P-metal pattern....27
圖3-12 金屬掀離(lift off)後-OM....28
圖3-13 金屬掀離(lift off)後-SEM....28
圖4-1 系統完整架構圖....29
圖4-2 驗證量測系統模態結果2D圖....30
圖4-3 驗證量測系統模態結果3D圖....30
圖4-4 驗證量測系統收光效率頻譜圖....31
圖4-5 Fabry-Perot量測的Δ....32

圖4-6 L-I&OSA量測系統結構圖....35
圖4-7 Undoped DWell Laser(C576) I-V....36
圖4-8 Undoped DWell Laser(C576) Log(I)-V ....37
圖4-9 P-type doping DWell Laser(C540) I-V....37
圖4-10 P-type doping DWell Laser(C540) Log(I)-V ....38
圖4-11 P-type doping DWell580 Laser(C600) I-V ....38
圖4-12 P-type doping DWell580 Laser(C600) Log(I)-V ....39
圖4-13 P-type doping DWell560 Laser(C602) I-V ....39
圖4-14 P-type doping DWell560 Laser(C602) Log(I)-V ....40
圖4-15 Undoped Laser(C576) & P-type doping Laser(C540) L-I....41
圖4-16 PWell580 Laser(C600) & PWell560 Laser(C602) L-I....42
圖4-17 Undoped Laser(C576) L=1.2mm OSA....44
圖4-18 P-type doping Laser(C540) L=1.2mm OSA ....45
圖4-19 PWell580 Laser(C600) L=1.2mm OSA....46
圖4-20 PWell560 Laser(C602) L=1.5mm OSA....47
圖4-21 不同樣品個別共振腔長lasing peak位置比較圖 ....48
圖4-22 Undoped Laser(C576) 內外部量子效率作圖 ....50
圖4-23 P-type doping Laser(C540) 內外部量子效率作圖 ....50
圖4-24 P-type doping Laser(C540) L=1.2mm-Net modal gain....51
圖4-25 PWell580 Laser(C600) L=1.2mm-Net modal gain....51
圖4-26 PWell560 Laser(C602) L=1mm-Net modal gain ....51
圖4-27 P-type doping Laser(C540) L=1.2mm - To ....53
圖4-28 QDs Laser高頻響應量測圖....53
表 目 錄

頁次
表3-1 ICP-RIE乾蝕刻條件表....24
表4-1 C576與C540不同腔長臨界電流密度及發光效率比較....42
表4-2 C600與C602不同腔長臨界電流密度及發光效率比較....42
表5-1 不同雷射結構量測結果總整理....54

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