本論文主要是將無電極遮光製程應用在尺寸為45 mil 的LED chip上，並配合高反射鏡面、粗化技術、電鍍銅基板製程以及雷射剝離技術，製備具高效率、高亮度以及高散熱之發光二極體元件，並且探討不同電極結構設計下的垂直結構發光二極體之光電與熱特性，以及與一般傳統水平製程發光二極體的特性作比較。
無電極遮光垂直結構氮化鎵發光二極體在研製過程中，經由表面粗化與高反射鏡面製程參數最佳化後，可以提供較佳的發光效率，使得無電極遮光的效果更加顯著。此外，透過將元件從藍寶石基板轉移至具良好散熱特性的銅基板，使得元件在高電流注入下，提升其散熱速度並且降低元件效率衰退效應。最後，利用無電極遮光技術，元件的亮度可以得到大幅提升。
本研究比較三種發光二極體結構如下：傳統藍寶石基板之發光二極體/具p-GaN粗化、垂直式無電極遮光結構(整面發光)發光二極體/具高反射鏡面銅基板、垂直式無電極遮光結構(指叉狀電極)發光二極體/具高反射鏡面銅基板三種結構。特性分析部分，垂直式無電極遮光結構(整面發光)和垂直式無電極遮光結構(指叉狀電極)之元件在350 mA操作電流下，垂直式無電極遮光結構(整面發光)和垂直式無電極遮光結構(指叉狀電極)之元件的輸出功率分別為284.52 mW和329.39 mW，比一般水平結構的236.38 mW分別增加約20.3 %和39.3%。由紅外熱像分析儀量測結果得知，垂直式無電極遮光結構(整面發光)和垂直式無電極遮光結構(指叉狀電極)的表面溫度分為51.02 °C和51.12 °C，低於一般水平發光二極體的表面溫度(57.91 °C)。
研究結果顯示，垂直式無電極遮光結構(指叉狀電極)比垂直式無電極遮光結構(整面發光)相對提升了15.7%的輸出功率，這是因為整面發光結構在大電流注入下會產生電流擁擠效應在n-type 電極周圍，經模擬證實，若將元件發光面積縮小，可以有效改善其缺點。

In this study, the embedded electrode process was employed in the LED chip (size: 45 mil). Moreover, the techniques of high reflective mirror, surface roughening, copper electroplated substrate and laser lift-off were also used to fabricate the LEDs with high efficiency, high brightness and high thermal conductivity. The effects of various electrode designs applied for the vertical-type LEDs on the device performance have been discussed, and the optoelectronic characteristics of vertical-type LEDs were compared with those of conventional lateral LEDs.
For the fabrication of GaN-based LED with embedded electrode, the good optoelectronic performance can be achieved by optimizing the fabricated conditions of surface roughening and high reflection mirror processes. The electrode-shading loss was eliminated by using the techniques as mentioned above. Furthermore, the employment of laser lift-off to transfer the LEDs from sapphire to copper substrate can both reduce the droop efficiency and enhance the thermal dissipation of device efficiently.
Three kinds of LEDs structures are designed to compared with optical and thermal properties, including C-LEDs, entire-type vertical embedded electrodes LEDs (E-LEDs), and finger-type vertical with embedded electrodes LEDs (F-LEDs). The output power at an injection current of 350mA of E-LEDs, F-LEDs, and C-LEDs were 284.52, 329.39 and 236.38mW, respectively. Moreover, the output power of E-LEDs and F-LEDs have 20.3 % and 39.3 % enhancement compared to C-LEDs, respectively. It reveals that E-LEDs and F-LEDs have significant improvement of light extraction using infrared thermal imaging analyzer. The surface temperature of F-LEDs, E-LEDs, and C-LEDs were measured to be 51.12, 51.02 and 57.91°C, respectively
The result indicates that the output power of the F-LED has 15.7% enhancement as compared with that of E-LED. This is attributed to the current crowding effect occurred around n-pad of E-LED at a high injection current. Through the simulation, it revealed that the release of current crowding effect can be obtained by reducing the emission area.

[1] T.C.Wen,S. J.Chang,L.W. Wu, Y. K. Su, W. C. Lai, C. H. Kuo, C. H. Chen, J. K. Sheu, and J. F. Chen, "InGaN/GaN tunnel-injection blue light-emitting diodes," Electron Devices, IEEE Transactions on, vol. 49, pp. 1095, 2002.
[2] D. B. Eason, W. C. Hughes, J. Ren, M. Riegner, Z. Yu, J. W. Cook, Jr., J. F. Schetzina, G. Cantwell, and W. C. Harsch, "High-brightness green light-emitting diodes," Electronics Letters,vol. 30, pp. 1178-1180, 1994.
[3] G. E. Stillman,V. M. Robbins, and N. Tabatabaie, "III-V compound semiconductor devices: Optical detectors," Electron Devices, IEEETransactions on, vol. 31, pp. 1643-1655, 1984.
[4] F.A. Kish, F. M. Steranka, D. C. DeFevere, D. A. Vanderwater, K. G. Park, C. P. Kuo, T. D. Osentowski, M. J. Peanasky, J. G. Yu, R. M. Fletcher, D. A. Steigerwald, M. G. Craford, and V. M. Robbins, "Very high-efficiency semiconductor wafer-bonded transparent-substrate (AlxGa1-x)0.5In0.5P/GaPlight-emitting diodes," Applied Physics Letters, vol. 64, pp. 2839-2841, 1994.
[5] F. A. Kish, D. A. Vanderwater, D. C. DeFevere, D. A. Steigerwald, G. E. Hofler, K. G. Park, and F. M. Steranka, "Highly reliable and efficient semiconductor wafer-bonded AlGaInP/GaP light-emitting diodes," Electronics Letters, vol. 32, pp. 132-134, 1996.
[6] J. I. Pankove and P. E. Norris, "Luminescence From GaN MIS Diodes.," Radio Corporation of America review, vol. 33, pp. 377-382, 1972.
[7] S. Yoshida, S. Misawa, and S. Gonda, "Epitaxial growth of GaN/AlN heterostructures,"Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, vol. 1, pp. 250-253, 1983.
[8] T. Sugahara, H. Sato, M. S. Hao, Y. Naoi, S. Kurai, S. Tottori, K. Yamashita, K. Nishino, L. T. Romano, and S. Sakai, "Direct evidence that dislocations are non-radiative recombination centers in GaN," Japanese Journal of Applied Physics Part 2-Letters, vol. 37, pp. L398-L400, Apr 1998.
[9] A. Y. Kim, W. Götz, D. A. Steigerwald, J. J. Wierer, N. F. Gardner, J. Sun, S. A. Stockman, P. S. Martin, M. R. Krames, R. S. Kern, and F. M. Steranka, "Performance of High-Power AlInGaN Light Emitting Diodes," Physica Status Solidi (a),vol. 188, pp. 15-21, 2001.
[10] O. B. Shchekin, J. E. Epler, T. A. Trottier, T. Margalith, D. A. Steigerwald, M. O. Holcomb,P. S. Martin, and M. R. Krames, "High performance thin-film flip-chip InGaN–GaN light-emitting diodes," Applied Physics Letters,vol. 89, pp. 071109, 2006.
[11] O. B. Shchekin, J. E. Epler, T. A. Trottier, T. Margalith, D. A. Steigerwald, M. O. Holcomb,P. S. Martin, and M. R. Krames, "High performance thin-film flip-chip InGaN–GaN light-emitting diodes," Applied Physics Letters, vol. 89, pp,071109, 2006.
[12] A. Schmitz, A. Ping, M. Khan, Q. Chen, J. Yang, and I. Adesida, "Metal contacts to n-type GaN," Journal of Electronic Materials, vol. 27, pp. 255-260, 1998.
[13] V. M. Bermudez, "Study of oxygen chemisorption on the GaN(0001)-(1x1) surface," Journal of Applied Physics, vol. 80, pp. 1190-1200, Jul 1996.
[14] 莊達人，VLSI製造技術，高立書局，第12-18頁，2002。
[15] D. A. Zakheim, I. P. Smirnova, I. V. Roznanskii, S. A. Gurevich, M. M. Kulagina, E. M. Arakcheeva, G. A. Onushkin, A. L. Zakheim, E. D. Vasil'eva, and G. V. Itkinson, "High-power flip-chip blue light-emitting diodes based on AlGaInN," Semiconductors, vol. 39, pp. 851-855, 2005.
[16] E. Letts, T. Hashimoto, M. Ikari, and Y. Nojima, "Development of GaN wafers for solid-state lighting via the ammonothermal method," Journal of Crystal Growth, vol. 350, pp. 66-68, Jul 2012.
[17] 施敏原著，張俊彥譯著，半導體元件物理與製程技術，第三版，高立圖書有限公司，台北，台灣，pp.192-206，2000。
[18] 郭浩中，賴芳儀，郭守義著，LED原理與應用 Principles and Applications of Light-emitting Diode，第二版，五南圖書出版股份有限公司，台北，台灣，pp.73-97，2012。
[19] V. M. Bermudez, "Study of oxygen chemisorption on the GaN(0001)-(1x1) surface," Journal of Applied Physics, vol. 80, pp. 1190-1200, Jul 1996.
[20] Z. L. Li, X. D. Hu, C. Ke, R. J. Nie, X. H. Luo, X. P. Zhang, T. J. Yu, B. Zhang, C. Song, Z. J. Yang, Z. Z. Chen, and G. Y. Zhang, "Preparation of GaN-based cross-sectional TEM specimens by laser lift-off," Micron, vol. 36, pp. 281-284, 2005.
[21] 史光國著，半導體發光二極體及固體照明，全華圖書股份有限公司，台北，台灣，pp.10-82，2010。
[22] Y. Xi and E. F. Schubert, "Junction-temperature measurement in GaN ultraviolet light-emitting diodes using diode forward voltage method," Applied Physics Letters, vol. 85, pp. 2163-2165, Sep 2004.
[23] S. Todoroki, M. Sawai, and K. Aiki, "Temperature distribution along the striped active region in high&-power GaAlAs visible lasers," Journal of Applied Physics, vol. 58, pp. 1124-1128, 1985.
[24] M. K. Kelly, O. Ambacher, B. Dahlheimer, G. Groos, R. Dimitrov, H. Angerer, and M. Stutzmann, "Optical patterning of GaN films," Applied Physics Letters, vol. 69, pp. 1749-1751, 1996.
[25] W. S. Wong, T. Sands, and N. W. Cheung, "Damage-free separation of GaN thin films from sapphire substrates," Applied Physics Letters, vol. 72, pp. 599-601, 1998.
[26] R. Groh, G. Gerey, L. Bartha, and J. I. Pankove, "On the thermal decomposition of GaN in vacuum," physica status solidi (a), vol. 26, pp. 353-357, 1974.
[27] S. Todoroki, M. Sawai, and K. Aiki, "Temperature distribution along the striped active region in high&-power GaAlAs visible lasers," Journal of Applied Physics, vol. 58, pp. 1124-1128, 1985.
[28] W. Wong, A. Wengrow, Y. Cho, A. Salleo, N. Quitoriano, N. Cheung, and T. Sands, "Integration of GaN thin films with dissimilar substrate materials by Pd-In metal bonding and laser lift-off," Journal of Electronic Materials, vol. 28, pp. 1409-1413, 1999.
[29] 郭浩中，賴芳儀，郭守義著，LED原理與應用 Principles and Applications of Light-emitting Diode，第二版，五南圖書出版股份有限公司，台北，台灣，pp.73-97，2012。
[30] S.R. Jeon, Y.H. Song, H.J. Jang, G. M. Yang, S. W. Hwang, and S. J. Son, "Lateral current spreading in GaN-based light-emitting diodes utilizing tunnel contact junctions," Applied Physics Letters, vol. 78, pp. 3265-3267, 2001.
[31] T. Margalith, O. Buchinsky, D. A. Cohen, A. C. Abare, M. Hansen, S. P. DenBaars, and L. A. Coldren, "Indium tin oxide contacts to gallium nitride optoelectronic devices," Applied Physics Letters, vol. 74, pp. 3930-3932, 1999.
[32] S. J. Chang, C. S. Chang, Y. K. Su, R. W. Chuang, W. C. Lai, C. H. Kuo, Y. P. Hsu, Y. C. Lin, S. C. Shei, H. M. Lo, J. C. Ke, and J. K. Sheu, "Nitride-based LEDs with an SPS tunneling contact Layer and an ITO transparent contact," Photonics Technology Letters, IEEE, vol. 16, pp. 1002-1004, 2004.
[33] S. M. Pan, R. C. Tu, Y. M. Fan, R. C. Yeh, and J. T. Hsu, "Improvement of InGaN-GaN light-emitting diodes with surface-textured indium-tin-oxide transparent ohmic contacts," Photonics Technology Letters, IEEE, vol. 15, pp. 649-651, 2003.
[34] T. Ding, A. P. J. Middelberg, T. Huber, and R. J. Falconer, "Far-infrared spectroscopy analysis of linear and cyclic peptides, and lysozyme," Vibrational Spectroscopy, vol. 61, pp. 144-150, 2012.
[35] S. A. Knickerbocker and A. K. Kulkarni, "Erratum: Estimation and verification of the optical properties of indium-tin-oxide based on the energy band diagram," Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, vol. 15, pp. 206-206, 1997.
[36] K. L. Lin, E. Y. Chang, Y. L. Hsiao, W. C. Huang, T. T. Luong et al, "Effects of AlxGa1−xN interlayer for GaN epilayer grown on Si substrate bymetal-organic chemical-vapor deposition,"Jounal of Vacuum Science and Technology B, vol. 28, pp. 473, 2010
[37] 高至鈞，汪建民，材料分析，中國材料科學學會，台灣，1998。