本論文旨在研發高功率垂直結構金屬基板之氮化鎵-基微蝕刻陣列發光二極體(MVM-LED)。我們以鍍鎳金屬基板取代藍寶石基板，結合區塊雷射剝離技術，製作高功率垂直結構金屬基板之氮化鎵-基發光二極體(VM-LED)，為進一步增加VM-LEDs之光析出效率，更利用黃光微影製程技術在n-GaN表面蝕刻出蜂巢狀微陣列之圖案，此蝕刻結構之邊長為4~10 μm且具有傾斜之側壁，除了因側壁結構而增加光析出之表面積，亦因傾斜之側壁進一步提升光析出之效率。在相同的試片條件之下，於20 mA電流注入時，MVM-LEDs與VM-LEDs得到相似的切入電壓特性曲線，顯示n-GaN表面蜂巢狀結構並未增加元件之串聯電阻；同時MVM-LEDs之光輸出與VM-LEDs於20 mA相較，增加30.1%，這歸始於具側壁出光之結構於光析出效率及面積之提升。再進一步搭配使用KOH溶液進行n-GaN表面處理，實驗結果揭示在20 mA電流注入時，經浸泡KOH 60秒處理之元件可得到最佳化之光輸出效率。與無KOH表面處理之VM-LEDs相較，經KOH處理之VM-LEDs與MVM-LEDs其光輸出功率分別增加了41%與77%。

In this thesis, a novel method to fabricate Micro-etching array Vertical-conducting Metal-substrate structure light emitting diode (abbreviated as MVM-LEDs) was demonstrated. The benefits and advancements were reported and discussed as well. Electroplating metal substrates technology was used with patterned laser lift-off (LLO) techniques for the transfer of sapphire substrate onto nickel metal substrates. To enhance the light extraction efficiency of VM-LEDs, the honeycombed micro-hole array were implemented on n-GaN through the use of photo lithography with Inductive Coupled Plasma (ICP) dry etching techniques. The dimensions of honeycombed micro-holes were defined to be with each edge of 4~10 μm with tilted sidewalls. In addition to the increase in the surface emission area, the proposed structure also raises the probability for the light to emit from the surface within the TIR angle. As compared to VM-LEDs of the same size, the electrical characteristics of the fabricated devices are similar, but with an enhancement in light output power by 31% at 20 mA. Furthermore, surface treatments with KOH at 60oC for 60s were made on the n-GaN layer to further improve the light output power. At an injection current of 20 mA, the light output power of the surface treated VM- and MVM-LEDs was 41% and 77% improved respectively as compared to that of regular VM-LEDs.

1. Nick Holonyak, Jr. and S. F. Bevacqua, “COHERENT (VISIBLE) LIGHT EMISSION FROM Ga(As1–xPx) JUNCTIONS,” Appl. Phys. Lett., vol. 1, no. 82, Dec. 1962.
2. H. Amano, N. Sawaki, I. Akasaki, and Y. Toyoda, “Metalorganic vapor phase epitaxial growth of a high quality GaN film using an AlN buffer layer,” Appl. Phys. Lett., vol. 48, no. 353, 1986.
3. Shuji Nakamura, Yasuhiro Harada, and Masayuki Seno, “Novel metalorganic chemical vapor deposition system for GaN growth,” Appl. Phys. Lett., vol. 58, pp. 2021, 1991.
4. T. Fujii, Y. Gao, R. Sharma, E. L. Hu, S. P. DenBaars, and S. Nakamura, “Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening,” Appl. Phys. Lett., vol. 84, no. 6, pp. 855–857, Feb. 2004.
5. M. Yamada, T. Mitani, Y. Narukawa, S. Shioji, I. Niki, S. Sonobe, K.Deguchi, M. Sano, and T. Mukai, “InGaN-Based Near-Ultraviolet and Blue-Light-Emitting Diodes with High External Quantum Efficiency Using a Patterned Sapphire Substrate and a Mesh Electrode,” Jpn. J. Appl. Phys., vol. 41, pp. L 1431–L 1433, 2002.
6. D. S. Han, J. Y. Kim, S. I. Na, S. H. Kim, K. D. Lee, B. Kim, and S. J.Park, “ Improvement of Light Extraction Efficiency of Flip-Chip Light-Emitting Diode by Texturing the Bottom Side Surface of Sapphire Substrate,” IEEE Photon. Technol. Lett,, vol. 18, no. 13, July. 2006.
7. Aurélien David, Tetsuo Fujii, Rajat Sharma, Kelly McGroddy, Shuji Nakamura, Steven P. DenBaars, Evelyn L. Hu, and Claude Weisbuch, “Photonic-crystal GaN light-emitting diodes with tailored guided modes distribution,” Appl. Phys. Lett., vol. 87, pp. 101–107, 2005.
8. M. K. Kelly, O. Ambacher, B. Dahlheimer, G. Groos, R. Dimitrov, H. Angerer, and M. Stutzmann, “Optical patterning of GaN films,” Appl. Phys. Lett., no. 12, pp. 1749-1751, Sep. 1996.
9. W. S. Wong, T. Sands, and N. W. Cheung, “Damage-free separation of GaN thin films from sapphire substrates,” Applied Physics Letters., no. 5, pp. 599-601, Feb. 1998.
10. 朱振甫，”利用雷射剝離技術製作氮化鎵發光元件之研究”，國立交通大學光電工程研究所博士論文，2003。
11. 李永春，”準分子雷射細微加工機一般使用者訓練教材”，國立成功大學機械工程系，2006
12. W. S. Wong, T. Sands, and N. W. Cheung, “Damage-free separation of GaN thin films from sapphire substrates,” Applied Physics Letters., no. 5, pp. 599-601, Feb. 1998。
13. 蕭棟升，”以雷射剝離技術進行具鍍鎳基板氮化鎵蕭基二極體之研製”，國立成功大學微電子工程研究所碩士論文，2005。
14. H. W. Choi, C. W. Jeon, and M. D. Dawson, “Tapered sidewall dry etching process for GaN and its applications in device fabrication,” J. Vac. Sci. Technol. B 23, Jan. 2005.
15. W. S. Wong, J. Krüger, Y. Cho, B. P. Linder, E. R. Weber, N. W. Cheung, and T. Sands, “Selective UV-laser processing for lift-off of GaN thin films from sapphire substrates,” in Proc. Symp. on Light Emitting Devices for Optoelectronic Applications and State-of-the-Art Program on Compound Semiconductors XXVIII, vol. 98-2, pp. 377-384, 1998.
16. 楊忠諺、葉源益，”乾式蝕刻於矽微加工及微機電方面之應用”，毫微米通訊，8卷4期：11~17，2001
17. K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, Y. Imada, M. Kato, and T. Taguchi, “High output power InGaN ultraviolet light-emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Jpn. J. Appl. Phys., vol. 40, no. 6B, pp. L583–L585, Jun. 2001.
18. T. N. Oder, K. H. Kim, J. Y. Lin, and H. X. Jiang, “III-nitride blue and ultraviolet photonic crystal light emitting diodes,” Appl. Phys. Lett., vol. 84, no. 4, pp. 466–468, Jan. 2004.
19. J. J.Wierer,M. R. Krames, J. E. Epler, N. F. Gardner,M. G. Craford, J. R. Wendt, J. A. Simmons, and M. M. Sigalas, “InGaN/GaN quantumwell heterostructure light-emitting diodes employing photonic crystal structures,” Appl. Phys. Lett, vol. 84, no. 19, pp. 3885–3887, May 2004.
20. D.-H. Kim, C.-O. Cho, Y.-G. Roh, H Jeon., Y. S. Park, J. Cho, J. S. Im, C. Sone, Y. Park, W. J. Choi, and Q.-H. Park, “Enhanced light extraction from GaN-based light-emitting diodes with holographically generated two-dimensional photonic crystal patterns,” Appl. Phys. Lett., vol. 87, pp. 203–508, Nov. 2005.
21. H.W. Choi, C.W. Jeon, M.D. Dawson, “Fabrication of matrix-addressable micro-LED arrays based on a novel etch technique,” Journal of Crystal Growth., vol. 268,pp. 527–530, 2004.
22. Jae-Soong Lee, Joonhee Lee, Sunghwan Kim, and Heonsu Jeon, “GaN-Based Light-Emitting Diode Structure With Monolithically Integrated Sidewall Deflectors for Enhanced Surface Emission,” IEEE Photon. Technol. Lett., vol. 18, no. 15, Aug. 2006.
23. Kai-Ming UANG, Shui-Jinn WANG , Shiue-Lung CHEN, Yu-Cheng YANG,Tron-Min CHEN and Bor-Wen LIOU, “Effect of Surface Treatment on the Performance of Vertical-Structure GaN-Based High-Power Light-Emitting Diodes with Electroplated Metallic Substrates,” Jpn. J. Appl. Phys., vol. 45, no. 4B, pp. 3436–3441, 2006.
24. Y. Gao, T. Fujii, R. Sharma, K. Fujito, S. P. Denbaars, S. Nakamura, and E. L. Hu, “Roughening Hexagonal Surface Morphology on Laser Lift-Off (LLO) N-Face GaN with Simple Photo-Enhanced Chemical Wet Etching,” Jpn. J. Appl. Phys., vol. 43, no. 5A, pp. L637-L639, 2004.
25. H. W. Choi, S. J. Chua, X. Xu, and Y. Sun, “Electrical Properties of ICP Plasma-Damaged n-GaN,” published by IPAP Conference Series 1, Tokyo, pp. 786-789, 2000.
26. L. C. Chen and Y. L. Huang, “High reliability GaN-based light-emitting diodes with photo-enhanced wet etching,” Solid-State Electronics, vol. 48, no. 7, Jul., pp. 1239-1242, 2004.
27. 楊於錚，”準分子雷射剝離技術應用於具鍍鎳金屬基板高功率垂直結構GaN基LEDs之研究”，國立成功大學微電子工程研究所碩士論文，2005。
28. 吳晉坤，”銦鋅氧化物透明導電薄膜應用於高功率GaN基LEDs之研究”，國立成功大學微電子工程研究所碩士論文，2004。