臺灣博碩士論文加值系統

近年來，高亮度發光二極體(High-Brightness Light Emitting Diodes)發展速度一日千里，已廣泛運用在通訊、交通、汽車、戶外看板以及顯示器背光源等，更由於其有體積小、耗電量低、使用壽命長、反應速度快、環保無污染等優點，期望未來能運用在照明上面，取代日光燈源與白織燈源。然而儘管磷化鋁鎵銦(AlGaInP)材料的磊晶技術可將內部量子效率(Internal Quantum Efficiency)幾乎達到100%，但是外部量子效率(External Quantum Efficiency)仍有許多改進的空間。原因在於光的取出受限於史涅耳定律(Snell’s Law)，以及光被基板材料所致。本論文的主要研究目的在於改變發光二極體晶片上的外型，藉由製作表面週期性結構，以提供光子不同的出光角度以及增加出光面積，藉以提昇發光效率。
我們首先針對二維表面週期性結構於磷化鎵窗口層(GaP Window layer)上的光取出行為作一模擬的預測，得知表面弧狀結構可以改善出光效率，接著運用半導體製程中，黃光顯影以及電感式耦合型電漿蝕刻(Inductive Coupling Plasma Etching)技術，成功製造不同圓形結構尺寸、間距與深度的表面週期性結構於發光二極體的窗口層上，並針對未封裝的軸上光與封裝後的光通量作量測，發現隨著週期性結構愈密，其表面散射出光機會增加，因此發光效率愈高，模擬預測與實驗結果相符；此外，由於窗口層上的週期性結構凹槽，讓其原本電流分佈均勻的功用受影響，當加工深度愈深，發光效率反而降低。最佳的發光效率發生在圓形結構尺寸為8μm，間距為4μm，深度為2μm的弧狀結構，其平均外部量子效率為4.79%，相較於未加工表面週期性結構的3.62%，平均提昇34.55%，在此取樣點中其最佳提昇47.23%，此時之外部量子效率為5.33%，發光效率為9.74lm/W(If=20mA)。
最後我們針對表面週期性結構設計一套結合晶片接合(Wafer-bonding)的製程，期望達到磷化鋁鎵銦高亮度發光二極體之發光極致。

摘要 I
目錄 II
圖目錄 IV
表目錄 XII

第一章 緒論 1
1-1 研究背景與動機 1
1-2 研究目的與論文架構 4

第二章 發光二極體工作原理、發光效率暨高亮度發光二極體之文獻回顧
與討論 5
2-1 引言 5
2-2 發光二極體之工作原理 6
2-3 發光二極體之發光效率 11
2-4 高亮度發光二極體之文獻回顧與討論 18
2-4-1 透明基板型LEDs 18
2-4-2 表面織狀型LEDs 21
2-4-3 光子晶體型LEDs 24
2-4-4 薄膜型LEDs 26

第三章 高亮度發光二極體之設計、模擬與製作 30
3-1 引言 30
3-2 高亮度發光二極體之設計 31
3-3 高亮度發光二極體之光取出效率模擬分析 34
3-4高亮度發光二極體之製程 43
3-4-1 試片準備 44
3-4-2 光罩設計 45
3-4-3 光阻塗佈 46
3-4-4 曝光顯影 47
3-4-5 電感式耦合型電漿蝕刻 48
3-4-6 歐姆接觸 55
3-4-7 元件切割與封裝 56

第四章 實驗結果與分析 57

第五章 結論與未來展望 87
5-1 結論 87
5-2 未來展望 89

參考文獻 91

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