氧化銦錫透明導電層於磷化鋁鎵銦發光二極體的應用 盧俊宇、蕭宏彬
E-mail: 9806469@mail.dyu.edu.tw
摘 要
氧化銦錫(Indium-Tin Oxide, ITO)對可見光具高度透明度及電傳導性，常當做一個透明電極，被廣泛地使用在發光元件上
。在傳統磷化鋁鎵銦(AlGaInP)材料的發光二極體上(Light-Emitting Diode, LED)，會有ITO與磷化鎵窗戶層(GaP window layer)難以形成良好歐姆接觸的問題，為解決這麼問題，本研究使用Ni/ITO層來與GaP形成良好的歐姆接觸。
本研究使用電子束蒸鍍系統在載玻片上面分別蒸鍍ITO(230 nm)與Ni(6 nm)/ITO(230 nm)，進行穿透率和片電阻的量測，接 著鍍在AlGaInP的LED上，與GaP和GaP/ITO結構的LED進行I-V和L-I的光電特性分析。
在本實驗中光波長630 nm下Ni/ITO薄膜穿透率可達91％。Ni/ITO膜在450 ℃空氣環境中以爐管退火15分鐘，得到最低的 片電阻值，應用在AlGaInP LEDs當作window layer的接觸層，在20 mA驅動電流下，GaP/Ni/ITO結構的LED操作電壓分別 比GaP和GaP/ITO結構LED降低0.04 V和0.13 V。在100 mA的驅動電流下，GaP/Ni/ITO結構的LED分別比GaP
和GaP/ITO結構LED的亮度增加23%和61.5%。
關鍵詞 : 氧化銦錫、磷化鋁鎵銦、發光二極體
目錄
封面內頁 簽名頁
博碩士論文暨電子檔案上網授權書………iii
中文摘要………iv
Abstract………v
致謝 ………vi
目錄 ………vii
圖目錄………ix
表目錄………xi
第一章. 緒論………1
1.1 研究背景………1
1.2 化合物半導體材?………2
1.3 發光機制………4
第二章. 理論………11
2.1 P-N接面原?………11
2.2 發光二極體的工作原?………11
2.3 高亮度AlGaInP 發光二極體………12
2.3.1 窗口層(window layer) ………13
2.3.2 電流阻障層 (Current Blocking Layer) …………13
2.3.3 透明導電層(transparent conductive layer) ………14
2.4 氧化銦錫(ITO) ………15
2.5 Ni/ITO薄膜特性………17
第三章. 實驗設備及流程………26
3.1 蒸鍍系統………26
3.2 穿透率量測………26
3.3 發光光強?（L-I）?測………27
3.4 XPS (X-ray Photoelectron Spectroscopy) ………27
3.5 ITO與Ni/ITO薄膜光電特性………28
3.6 LED元件製作………29
3.6.1 試片清潔………29
3.6.2 蒸鍍ITO及Ni/ITO………29
3.6.3 ITO、Ni/ITO退火………30
3.6.4 黃光微影定義P電極區域………30
3.6.5 蒸鍍P電極及N電極………31
3.6.6 PN電極退火………31
第四章. 實驗結果分析………38
4.1 Ni、ITO及Ni/ITO薄膜穿透率分析………38
4.2 Ni、ITO及Ni/ITO薄膜片電阻分析………39
4.3 電壓-電流(I-V) 特性分析………39
4.4 發光強度-電流(L-I)特性分析………41
4.5 XPS縱深成份分析………42
第五章. 結論………53
參考文獻………55 參考文獻
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