本論文主要研究內容為提升氮化物發光二極體之光取出效率。特別針對晶粒製程中之透明導電層(TCL、Transparent Conductive Layer)之處理做研究比較。本論文實驗片所選用之TCL層為以E-Beam蒸鍍之氧化銦錫(ITO，Indium Tin Oxide)。
本論文之研究方法之理論基礎在於降低晶粒的內部全反射(TIR，Total Internal Reflection)以提升晶粒的出光效率。實驗結論為針對平坦表面(Flat Epiwafer) 磊晶片若在ITO層導入粗糙化可以有極佳之亮度提升效果，而對於粗糙表面(Rough Epiwafer)之磊晶片於ITO層進行Mesh處理(蝕刻成特殊圖形) 可以有極佳之亮度提升效果。
實驗分成兩部分，第一部分係分別選擇平坦表面與粗糙表面之磊晶片，在完成 ITO層之製程後，對ITO層進行粗糙化之處理。所採用之方式為將晶片置入30% HCl水溶液中，進行不同作業時間之處理。無論是平坦表面磊晶片或是粗糙表面磊晶片，均以蝕刻時間30秒之亮度提升效果最佳，分別為3.8%與 1.4%。平坦表面磊晶片之20mA順向電壓未提高。對於粗糙表面磊晶片因為對ITO層進行粗糙化之處理，有極高之機會造成ITO層斷面之情形，故同樣在30秒之蝕刻條件下，雖然亮度有1.4%之提升，但20mA之順向電壓提高了0.06V。
實驗第二部分分別對平坦表面與粗糙表面之磊晶片進行ITO層四種不同方式之處理。分別為ITO層不再做任何處理、以鹽酸進行粗糙化、ITO層進行Mesh處理(蝕刻成特殊圖形) 、粗糙化及Mesh製程同時進行。
在平坦表面磊晶片，粗糙化、Mesh製程、粗糙化+Mesh製程亮度提升效果分別為3.5%、1.7%、5.4%。20mA之順向電壓分別提高0.005V、0.015V、0.020V。綜合考量製程成本、亮度提升效果與20mA之順向電壓提高程度，粗糙表面仍是極適當可導入之製程。
對於粗糙表面磊晶片，粗糙化、Mesh製程、粗糙化+Mesh製程亮度提升效果分別為-0.2%、3.9%、-0.2%。20mA之順向電壓均未提高。故對於粗糙表面磊晶片，Mesh製程是極適當可導入之製程。
後續將繼續往下列方向進行研究。方向一為ITO層不同處理方法之持續研究開發。方向二為在ITO層蒸鍍前，成長其他化合物例如SiO2或 TiO2 並蝕刻成其他不同形狀搭配上述粗糙化以及mesh製程進行亮度提升之比較。方向三為使用濺鍍機台沉積ITO薄膜，比較不同ITO層處理方法之光取出效率比較。

In this thesis, we focus on the study of GaN-based LED light extraction issue. We compare the different treatments on TCL (Transparent Conductive Layer) of chip process. We use the ITO material for TCL process in this thesis.
We had drawn the following conclusions.
1.To compare the different treatment time(15s、30s、45s、60s) of 30% HCl solution on ITO layer roughing process, we obtain the best result in 30s condition. The enhancement of Iv@20mA are 3.8% and 1.4% for Flat Epiwafer and Rough Epiwafer respectively.
2.The mesh process(ITO Layer with pattern) is suitable to Rough Epiwafer that the enhancement of Iv@20mA is 3.9%.

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