- 學位論文
以溶膠-凝膠法製備二氧化矽應用於發光二極體表面粗化之研究
The Application of Nano-particles of Silicon Dioxide by Sol-Gel process on Light Emitting Diode roughness
摘要
本論文利用溶膠-凝膠法 (sol-gel) ，以矽化四乙酯（TEOS）為前驅物，藉由調配氨水比例，合成不同粒徑之二氧化矽球體，並利用掃描式電子顯微鏡 (SEM) 及粒徑分析儀觀測二氧化矽球體尺寸及分布狀況。利用合成之二氧化矽球體做為遮罩並藉由乾式蝕刻方式進行發光二極體表面粗化，以達提升發光二極體出光效率之目的。表面粗化實驗配合SAS軟體規劃實驗設計，探討各因子對於發光二極體表面粗化製程之影響，並利用回應曲面法建立各因子對軸向亮度影響之模型，進而求得最佳值。本實驗所探討之因子為球徑大小(180~500nm)、塗佈速度(500~3500rpm)及蝕刻深度(60~300nm)，目標函數為軸向亮度。由回應曲面法計算結果發現，此三項因子對於軸向亮度皆有顯著影響，且在球徑為409nm、塗佈速度為500rpm、蝕刻深度為234nm時會有最佳軸向亮度值120.76mcd。利用計算所得之最佳參數值進行實驗，所得三次軸向亮度平均值為121mcd，標準差為2.94mcd，發現實驗結果與理論計算值相符合，因此可知利用回應曲面法所得之模型可適用於本實驗設計。與表面未粗化之發光二極體相比，最佳粗化條件下，其出光效率可增加達25%。
並列摘要
In this study, we synthesize a variety of sizes of SiO2 nano-spheres from TEOS, the precursor, with varied ratio of Ammonia Aqua by the Sol-Gel method. The sizes and the distribution of SiO2 nano-spheres on LED-Epitaxy Wafer are observed by Scanning Electron Microscopy (SEM) and Particle Analyzer. Further, we apply SiO2 nano-spheres as a hard mask to obtain patterned and roughing wafer surface by which the light extraction efficiency increases. For the roughen experiment investigation, we consider several parametric factors with the help of SAS software, and we obtain the optimal value of the model established by the response curve method. Those parametric factors are sphere dimension, 180~500nm, spin-coated rotation speed, 500~3500rpm, and etching depth, 60~300nm, respectively. And their target function is the axial luminous intensity. From the response curve method, all these three factors possess phenomenal degree of influence on the axial luminous intensity. The optimized value of the luminous intensity from calculation is 120.76mcd while these values, 409nm, 500rpm, and 234nm are being designated for the three corresponding factors. The experimental value of the luminous intensity on average is 121mcd with the standard deviation of 2.94mcd while the designated values are being used. Under the optimized roughen condition, the light extraction efficiency increases up to 25% in comparison with non-roughen LED sample.