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標題: 發光二極體光取出效率製程研究
The Process for Increasing in Extraction Efficiency of LED
作者: 曾國航
Tseng, Guo-Hang
關鍵字: Photoelectrochemical (PEC);光輔助電化學氧化蝕刻;roughen;n-GaN;undercut;Micro-PL;粗化;n型氮化鎵;倒角;微光激螢光光譜
出版社: 精密工程學系所
引用: [1]. Shuji Nakamura, Takashi Mukai and Masayuki Senoh, Jpn. J. Appl. Phys., Vol.30 p.1991 (1998). [2]. Shuji Nakamura, Takashi Mukai and Masayuki Senoh, Appl. Phys. Lett., Vol.64, p.1687 (1994). [3]. J.C. Carrano, T. Li, P. A. Grudowski, C. J. Eiting, R. D. Dupuis, and J.C. Campell, Appl. Phys. Lett., Vol.72, p.542 (1998) [4]. C. Gaquiere, S. Trassert, B. Boudart, and Y. Crosnier, IEEE Microwave and Guided Wave Letters, Vol. 10, No.1 (2000) [5]. R. J. Shul, G. B. McClellan, S. A. Casalnuovo, D. J. Rieger, S. J. Pearton, C. Consantine, C. Barratt, R. F. karlicek, Jr., C. Tran, and M.churman, Appl. Phys. Lett. Vol.69, p.1119 (1996) [6]. C. Youtsey, I. Adesida and G. Bulman, Appl. Phys. Lett., Vol.71 p.2151 (1997) [7]. L. H. Peng, C. W. Chuang, J. K. Ho, C. N. Huang, and C. Y. Chen , Appl. Phys. Lett., Vol.72, p.939 (1998) [8].M. R. Krames, M. Ochiai-Holcom, G. E. Ho¨ fler, C. Carter-Coman, E. I. Chen,I.-H. Tan, P. Grillot, N. F. Gardner, H. C. Chui, J.-W. Huang, S. A. Stockman, F. A. Kish,and M. G. Craford,T. S. Tan, C. P. Kocot, and M. Hueschen, J. Posselt, B. Loh, G. Sasser, and D. Collins, Appl. Phy. Lett,VOL.75, p.2365(1999) [9]. S. J. Pearton, J. C. Zolper, R. J. Shul and F. Ren, J. Electrochem, Solid-State Lett., Volume 4, Issue 5, pp. G39-G41 (May 2001) Appl. Phys. Vol.86, No.1 [10].Chih-Chiang Kao, Hao-Chung Kuo, Hung-Wen Huang, Jung-Tang Chu, Yu-Chun Peng, Yong-Long Hsieh, C. Y. Luo, Shing-Chung Wang, Chang-Chin Yu, and Chia-Feng Lin, IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 17, NO. 1, JANUARY (2005) [11].T. Fujii,Y. Gao, R. Sharma, E. L. Hu, S. P. DenBaars, and S. Nakamura Appl. Phys. Lett., Vol. 84, No. 6, 9 February (2004) [12].L.-H. Peng, C.-H. Liao, and Y.-C. Hsu, C.-S. Jong, C.-N. Huang, J.-K. Ho, C.-C. Chiu, and C.-Y. Chen, Appl. Phys. Lett., Vol. 76, No. 4, 24 January (2000) [13].T. Rotter, D. Mistele, J. Stemmer, F. Fedler, J. Aderhold, and J. Graul V. Schwegler, C. Kirchner, and M. Kamp ,M. Heuken, Appl. Phys. Lett., Vol. 76, No. 26, 26 June (2000) [14].J. W. Seo, C. S. Oh, H. S. Jeong, J. W. Yang,a) K. Y. Lim, C. J. Yoon, and H. J. Lee, Appl. Phys. Lett., Vol. 81, No. 6, 5 August (2002) [15]. J. E. Borton, C. Cai and M. I. Nathan, P. Chow, J. M. Van Hove, and A. Wowchak, and H. Morkoc, Appl. Phys. Lett., Vol. 77, p.1227,(2000) [16].史光國,”現代半導體發光及雷射二極體材料技術,”全華科技,台北 ,台灣,4-1~4-10(2001) [17].J.K. Sheu, Y.K. Su, G.C. Chi, W.C. Chen, C.Y. Chen, C.N. Huang, and J.M. Hong, Y.C. Yu, C.W. Wang, and E.K. Lin, J. Appl. Phys. 83,3172 (1998) [18]. J.K. Ho, C.S. Jong, C.C. Chiu, C.N. Huang, and K.K. Shih, L.C. Chen, F.R. Chen, and J.J. Kai, J. Appl.Phys.86,4491(1999)
本論文研究藉由表面粗化與倒角結構提昇氮化鎵發光二極體的光取出效率,進而增加外部量子效率。傳統氮化鎵發光二極體的內部量子效率與光取出效率有相當明顯的差異,差異來自於光由高折射率氮化鎵材料射出至低折射率的空氣中,形成較小之光臨界角,真正脫離氮化鎵結構的效率降低,我們利用光輔助電化學氧化蝕刻方式在 n 型氮化鎵表面形成氧化鎵層,再以鹽酸將氧化鎵層去除,形成孔狀的粗化結構及 n 型氮化鎵側壁的倒角結構,在不同的光輔助電化學氧化蝕刻實驗參數下的 n 型氮化鎵表面結構將造成對光取出效率的差異。
量測微光激螢光光譜比較表面粗化程度對光脫離 n 型氮化鎵表面的影響,並使用場發射電子顯微鏡觀察 n 型氮化鎵表面與側壁,證明 n 型氮化鎵表面粗化與側壁倒角結構可以增加 30%~40% 的光輸出功率。
最後將基板磨薄切割劈裂成晶粒,並且以 TO-Can 與 Lamp 形式封裝,量測電性資料與光學特性,發現表面結構的改變也影響發散角度,經過處理的晶粒有較大的發散角度,最終封裝成 Lamp 形式的光輸出功率增加14.6%。

In the thesis, we use surface textured and sidewall undercut structure to increase light escape and improve the external quantum efficiency of GaN base- LED. The light extraction efficiency is lower than internal quantum efficiency. The reason for this difference is the reduced critical angle for light in high refractive index GaN (n=2.5) to the air (n=1). We use Photoelectrochemical (PEC) oxidation process to form the Ga2O3 layer and remove the oxide layer in dilute HCl solution. The roughen GaN surface and sidewall undercut structure are observed in PEC treated LED structure. This surface textured structure has increased light escape efficiency.
We use field-emission scanning electron microscopy (FE-SEM) to analyze the n-GaN rough surface and sidewall undercut structure. The light escape efficiency from LED structure is measured through Micro-photoluminescence (u-PL). The light extraction of the PEC-treated LED is increased about 30%~40%.
Finally, the PEC-treated LEDs are packeted as the TO-Can and Lamp formal to measure the output power. The fabricated LEDs through the PEC process have 14.6% output power enhanced compared with the general LED at 20 mA operation current.
其他識別: U0005-2308200622381200
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