臺灣博碩士論文加值系統

近年來氮化鎵發光二極體的發展已得到蓬勃發展，但在固態照明最主要的發光效率部分仍有改善空間。發光效率中的光萃取效率因內部全反射導致光被侷限於氮化鎵材料內，導致光萃取效率偏低，這一現象和氮化鎵材料本身高折射係數有關。
本篇論文採用電子束微影搭配電感耦合式電漿蝕刻於氮化鎵系列發光二極體的表面P型氮化鎵上製作次波長光柵週期性結構，用以提升發光二極體的亮度。研究主題可區分為兩大部分。第一部份，
固定空氣佔有率，改變週期結構，求最佳週期結構。第二部份，固定週期結構，改變光柵線寬，求最佳空氣佔有率。針對不同週期和佔有率做探討。
於氮化鎵發光二極體的表面P型氮化鎵上製作次波長光柵週期性結構，歸納出的最佳週期和最佳空氣佔有率的發光強度相較於平面基板提升約24%，非最佳週期與非最佳空氣占有率的發光強度也有約10%-20%的提升。綜合以上結果，製作次波長光柵週期性結構能夠有效提升光萃取效率。

For last few years, the GaN-based light emitting diodes(LEDs) have great developed. But in the illumination applications, light extraction of GaN-based LEDs remains limited, one of the most significant problem is the total internal reflection of trapped light within GaN material with high refractive index.
In this dissertation, for improving the light extraction efficiency, electron-beam lithography and inductively plasma dry etching were used to achieve sub-wavelength grating-periodic structures with exact dimensions on the p-side of nitride-based LEDs with multiple quantum wells. The main focus of the dissertation can be divided into two parts. First, fixed the Air duty cycle, change the period of structure, to find the best period. Second, fixed the period of structure, change the part of air, to find the best air duty cycle. Done for different periods and air duty cycle in discussion.

指導教授推薦書.........................................................
口試委員審定書......................................................... 授權書.............................................................iii
誌謝................................................................iv
中文摘要............................................................v
英文摘要............................................................vi
目錄...............................................................vii
圖表目錄.............................................................ix
第一章 導論........................................................1
1-1 研究動機.........................................................1
1-2 文獻回顧與探討....................................................2
第二章 光萃取率理論.................................................3
2-1光萃取率理論.......................................................3
2-1-1全反射角損耗..................................................3
2-1-2菲捏爾損失....................................................4
2-1-3材料吸收.....................................................6
2-2電激發光量測.......................................................7
第三章 實驗樣品製備....................................................9
3-1實驗設計..........................................................9
3-2實驗樣品製備.......................................................10
3-2-1 常壓大陽日酸有機金屬氣相沉積....................................10
3-2-2 電子束微影製程技術............................................12
3-2-3 週期性結構製作流程...........................................14
3-2-4 發光二極體元件製作流程........................................19
3-2-5 聚焦離子束顯微鏡與Micro-PL系統.................................23
3-2-6 藍光封裝製程..................................................26
第四章 實驗量測與分析...................................................27
4-1 一維週期性光柵結構..................................................27
4.2 決定次波長一維光柵結構之週期..........................................28
4-3 實驗討論...........................................................29
4-3-1 固定空氣佔有率，改變週期結構，求最佳週期結構.........29
4-3-2 固定週期結構，改變光柵線寬，求最佳空氣佔有率.........35
第五章 結論.............................................................44
5-1 總結論.............................................................44
5-2 未來研究方向........................................................45
參考文獻................................................................46
圖表目錄
圖2.1 (a)臨界角的示意圖；(b)圓形錐的面積元素；(c)圓形錐.....................4
圖2.2 菲捏爾損失示意圖...................................................5
圖2.3 光線在半導體內的材料吸收現象........................................6
圖2.4 電激發光儀器架構示意圖.............................................8
圖3.1 固定空氣佔有率50%，不同波段的對應強度圖..............................9
圖3.2 (a)常壓大陽日酸有機金屬氣相沉積機台; (b)磊晶結構圖...................11
圖3.3 (a)電子束微影系統；(b)光柵結構樣品面...............................13
圖3.4 光柵週期性結構製作流程圖..........................................18
圖3.5 元件製備完成示意圖...............................................23
圖3.6 (a)聚焦離子束顯微鏡系統； (b)樣品傾斜0與45圖.......................24
圖3.7 微觀光致激發螢光光譜系統圖........................................25
圖3.8 藍光封裝完成示意圖...............................................26
圖4.1 一維光柵週期結構之示意圖..........................................27
圖4.2 一維次波長光柵SEM圖(a)週期結構180nm；(b)週期結構
210nm；(c) 週期結構240nm...................30
圖4.3 電激發光光譜積分強度.................................................31
圖4.4 改變週期順向偏壓特性圖..............................................33
圖4.5 空氣佔有線寬所形成之缺陷.............................................34
圖4.6 週期結構180nm電激發光光譜積分強度...................................36
圖4.7 週期結構210nm電激發光光譜積分強度...................38
圖4.8 週期結構240nm電激發光光譜積分強度.......................40
圖4.9 順向偏壓電特性圖(a)180nm(b)210nm(c)240nm.............43
表3.1 電子束微影系統(ELS-7500)相關參數............................12
表4.1 固定空氣佔有率參數表.............................................29
表4.2 三組結構在電流350mA下積分強度值與對Reference的相對值......... 31
表4.3 三組結構在電流350mA下的驅動電壓值......................33
表4.4 週期結構180nm改變空氣線寬參數表..........................35
表4.5 空氣線寬80nm、90nm之SEM圖.............................36
表4.6 週期結構180nm積分強度相對值....................................37
表4.7 週期結構210nm改變空氣線寬參數表..........................37
表4.8 空氣線寬70nm、80nm、100nm之SEM圖..........................38
表4.9 週期結構210nm積分強度相對值................................39
表4.10 週期結構240nm改變空氣線寬參數表..........................39
表4.11 空氣線寬90nm、110nm、130nm之SEM圖........................40
表4.12 週期結構240nm積分強度相對值..............................41

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