本實驗乃利用電鍍(Electroplating)技術取代晶圓鍵合(Wafer Bonding)以達到基板轉移之目的，此技術可達到低成本、解決良率問題、減少晶圓鍵合衍生出的熱應力等優點，並利用雷射剝離(Laser Lift-Off)技術移除導電性、散熱性均不佳的藍寶石基板(Al2O3, Sapphire)，以製作薄膜式氮化鎵發光二極體(Thin-GaN LED)之元件。此外，藉由拉曼(Raman)量測及Kozawa方程式計算來探討成長在不同電鍍銅基板厚度下的氮化鎵磊晶層之應力變化，並獲得磊晶層之最小殘留應力，且透過改變氮化鎵磊晶層應力來減少量子侷限史塔克效應(Quantum-Confined Stark Effect, QCSE)以達到增進氮化鎵發光二極體元件之內部量子效率(Internal Quantum Efficiency, IQE)為目的。最後，光致發光光譜(Photoluminescence, PL)用於分析磊晶層能隙變化。      
結果發現，波長出現藍位移，如此證明利用基板轉移的方式使磊晶層之應力狀態被獲得改善，並進一步避免了QCSE現象及提升內部量子效率。

We use electroplating technique instead of wafer bonding, because the technique can achieve cost saving、solve yield issues and avoid thermal stress derived from the wafer bonding. Then, laser lift-off technique to remove sapphire substrate which has low thermal and electrical conductivity. In this way, we can get the complete thin-GaN LED structure. 
Also, we apply this structure to analyze QCSE phenomena under various thicknesses of copper substrate to reach the goal of under various thicknesses of copper substrate and further enhance the internal quantum efficiency. Besides, we use Raman measurement and Kozawa equation to calculate the changes of the compressive stress of GaN epitaxial layer. PL spectra is adopted to prove the changes of energy bandgap of GaN epitaxial layer. 
Finally, we find the blue shift and confirm that it can avoid QCSE phenomena by changing stress-state of GaN epilayer.

中文摘要 I
英文摘要 III
目錄 V
圖目錄 VIII
表目錄 XI

第一章 序論 1 
1-1 前言 1	   
1-2 研究目的 2    
1-3 論文架構 5
第二章 理論基礎與實驗裝置及原理 6
2-1 發光二極體之相關理論 (Light Emitting Diode, LED) 6
2-1-1 簡介 6      
2-1-2 發光二極體主要結構 7      
2-1-3 發光二極體效率介紹 8
2-1-3-1 內部量子效率 (Internal Quantum Efficiency, IQE) 8
2-1-3-2 光取出效率 (Light Extraction Efficiency, LEE) 9
2-1-3-3 外部量子效率 (External Quantum Efficiency, EQE) 9
2-2 氮化鎵薄膜之特性 9
2-2-1 薄膜應力 9
2-2-2 薄膜應力來源 10
2-2-3 極化現象 12
2-2-4 極化現象之影響 14
2-3 實驗裝置及原理 15
2-3-1 電子槍及熱蒸鍍 (E-gun and Thermal Evaporation) 15
2-3-2 電鍍技術 (Electroplating Technology) 16
2-3-3 雷射剝離技術 (Laser Lift-Off Technology) 18
2-3-4 拉曼光譜量測 (Raman Spectrum) 19
2-3-4-1 拉曼光譜原理 19
2-3-4-2 聲子振動模式 22
2-3-5 光激發螢光光譜 (Photoluminescence, PL) 23
第三章 實驗方法與步驟 25
3-1 氮化鎵晶片結構 25
3-2 晶片清洗 26
3-3 電子槍蒸鍍金屬層 26
3-4 電鍍銅製程 27
3-5 雷射剝離製程 30
3-6 ICP乾蝕刻製程 30
3-7 定義晶片區域 30
3-8 鈍化層(Passivation Layer)製作 31
3-9 定義N型電極區域 32
第四章 結果與討論 34
4-1 熱應力 34
4-2 本質應力 36
4-3 電流密度影響應力 38
4-4 晶粒(Grain Size)成長誘導應力 41
4-4-1 薄膜成長機制 41
4-4-2 薄膜應力演變 42
4-4-3 晶粒尺寸演變 44
4-5 Raman量測 45
4-6 變功率PL量測 51
4-7 變溫PL量測 53
第五章 結論與未來展望 56
5-1 結論 56
5-2 未來展望 56

圖目錄
圖1.1 直接能隙與間接能隙比較圖 2
圖1.2 半導體材料之能隙發光光譜圖 2
圖1.3 Wurtzite結構示意圖 4
圖1.4 氮化鎵之(0001)面與藍寶石基板之(0001)面原子排列關係圖 4
圖1.5 材料晶格常數與能隙關係圖 5
圖2.1 發光二極體之多重量子井結構 6
圖2.2 目前市面上主流LED之結構圖 7
圖2.3 電流聚集現象 8
圖2.4 薄膜應力示意圖 10
圖2.5 氮化鎵磊晶層磊晶至Sapphire之熱應力示意圖 11
圖2.6 左圖為氮化鎵之Wurtzite結構，右圖為自發極化現象 13
圖2.7 氮化鎵磊晶層之極化現象 14
圖2.8 量子侷限史塔克效應 15
圖2.9 電子槍及熱蒸鍍機外觀示意圖 16
圖2.10 電鍍裝置圖 18
圖2.11 雷射剝離(Laser Lift-Off)示意圖 19
圖2.12 瑞利散射、史托克散射和反史托克散射示意圖 21
圖2.13 光譜強度比較圖 21
圖2.14 拉曼震動模態示意圖 23
圖2.15 電子躍遷示意圖 24
圖3.1 氮化鎵晶片結構 25
圖3.2 Thin-GaN製程示意圖 29
圖3.3 定溫、定電流密度下、改變時間之銅厚度曲線圖 29
圖4.1 熱應力變化示意圖 36
圖4.2 本質應力變化示意圖 38
圖4.3 不同電流密度下，銅原子繞射面比較圖 39
圖4.4 不同電流密度下，銅之舒張應力比較圖 39
圖4.5 由ICDD提供的銅繞射資訊的標準圖譜 40
圖4.6 銅基板厚度為200 μm之晶格繞射圖譜 40
圖4.7 薄膜沉積步驟 42
圖4.8 Low-atom Mobility和High-atom Mobility之應力變化 43
圖4.9 晶粒聚集前後示意圖 44
圖4.10 晶粒大小變化示意圖 44
圖4.11 銅基板厚度與氮化鎵磊晶層壓縮應力釋放量曲線圖 46
圖4.12 銅厚度和舒張應力之關係圖 49
圖4.13 三種不同銅厚度下之晶粒尺寸 49
圖4.14 不同銅厚度之SEM示意圖 50
圖4.15 不同銅厚度之變功率PL光譜圖 51
圖4.16 銅厚度為300 μm之變溫PL光譜圖 54

表目錄
表2.1 氮化物之晶格常數和熱膨脹係數材料參數 12
表2.2 各材料之熱傳導係數 17
表3.1 常見金屬之功函數 33
表4.1 不同厚度銅基板厚度下激發功率與波長位移量比較表 52

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