使用氧化鎵鋅透明膜增加氮化鎵基發光二極體光取出

Light Extraction Enhancement of GaN-Based LEDs by Using Gallium Zinc Oxide Transparent Film

徐榮利(Jung-Li Hsu)

指導教授 ： 林俊良

共同指導教授 ： 甘廣宙(Kwang-Jow Gan)

崑山科技大學/工程學院/電子工程研究所/碩士(2009年)

摘要

本論文使用鎵鋅氧化物(Gallium Zinc Oxide, GZO)透明膜探討其材料特性，及GZO 薄膜經過乾式蝕刻後應用於藍光發光二極體(Light Emitting Diode, LED)，探討表面粗糙化對光取出之影響。
第一部分，利用射頻磁控濺鍍系統沉積GZO薄膜於玻璃基板上，藉由改變濺鍍條件中之射頻功率、氬氣流量與工作壓力等參數，探討製程參數對於沉積GZO薄膜之結晶特性、表面形貌、電特性及光學特性的影響，結果找出波長450 nm最佳穿透率製程條件之GZO透明膜。
第二部分，採用波長450 nm最佳穿透率製程條件下之GZO 透明膜進行蝕刻處理，本研究使用微波電漿化學氣相沈積系統進行氫電漿乾式蝕刻處理，在不過度蝕刻GZO透明膜的條件下觀察不同蝕刻時間表面形貌與蝕刻深度對光穿透率之影響。
第三部分，利用LED粗化表面的觀念來研究表面粗糙如何影響光特性。將蝕刻與未蝕刻之GZO透明膜應用於尺寸大小為14 mil × 17 mil藍光LED上，由實驗結果可以觀察得知粗糙度與蝕刻深度不足無法有效的使光散射到外部，導致內部吸收，光取出效率不佳；適當之粗糙度與蝕刻深度有助於藍光LED光取出。

關鍵字

射頻磁控濺渡 ； 鎵鋅氧化物 ； 發光二極體

並列摘要

In this work, the gallium doped zinc oxides were prepared by R.F. magnetron reactive sputtering. Define the range of parameters to prepare the optimum characteristic of GZO thin films. Then, we have focused on surface roughness of the light extraction by various H2 etching parameters for blue LED application. There are there parts of this study:
The first part, the effect of sputtering parameters on crystalline structure, surface morphology, electrical, and the optical properties of GZO thin films were studied. Sputtering parameters were adjusted to obtain the optimal structures that yield the suitable optical properties in 450 nm wavelength for blue LED application.
The second part, the GZO thin films were etched by microwave plasma chemical vapor deposition with H2 ambient. After etching in H2 plasma with different etching time they develop a dissimilar surface texture, which leads to different extraction of light.
The third part, finally, we were manufacture the as-etched sample and etched sample on blue LED. The results prove the suitability of our approach of using sputtered and H2 plasma etched of GZO thin films to produce highest extraction of light for blue LED.

並列關鍵字

R.F. sputter ； GZO ； LED

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