發光二極體(Light Emitting Diode, LED)的壽命及性能較傳統光源優異許多，但是散熱的問題一直是影響發光二極體發光效率與壽命的關鍵原因之一。而氮化鎵材料為了降低生產成本，必須磊晶在藍寶石基板上。欲解決藍寶石基板散熱不佳的問題，本論文研究覆晶封裝，採用金屬共晶接合，以Ti/Cu/Sn厚度分別為500 Å、15000 Å、10000 Å，鍍製於氮化鎵與矽晶圓上。於晶圓表面均勻塗上松香助焊劑，並對晶圓加溫、加壓，使能通過我們設定的非破壞性剪切力測試。並結合商用雷射剝離藍寶石基板技術，將氮化鎵薄膜轉移至矽基板上。
剝離藍寶石基板後，GaN薄膜有零星斑駁的點狀，使用顯微鏡觀察發現為因GaN薄膜破裂而致使焊料從底部溢出，而未破裂區有許多地方呈現下凹起伏，推測是解離反應時的高溫使焊料局部液化所產生的應力造成。
目前我們雷射剝離藍寶石基板製程的良率很低，常發生晶片先由GaN與Silicon交界處脫離，推測是由於雷射掃描剝離藍寶石基板時產生高溫，會局部液化Solder，如果晶片面積不大(約1 cm x 1 cm)，會發生整片的Solder均液化而移動。這可以解釋為何廠商處理2” 晶圓的雷射剝離藍寶石基板無此問題。

The lifetime and performance of Light Emitting Diode (LED) are much better than traditional light sources. However, the heat dissipation of LEDs has always been one of the key reasons affecting the luminous efficiency and lifetime of LEDs. In order to reduce production costs, Gallium nitride materials must be epitaxially grown on sapphire substrates.

By using a flip-chip package and eutectic bonding in this thesis to solve the problem of poor heat dissipation of the sapphire substrate. The solder thickness is 25000 Å (Ti/Cu/Sn=500 Å/15000 Å/10000 Å). Firstly, we deposited solder on the surface of sapphire and silicon, and then we applied rosin flux evenly to the surface of the wafer. After that, heating up both the GaN wafer and the silicon wafer. In the meantime, we pressurized them. While cooling down from the hot plate, the wafer bonding process was completed. A few of those wafers passed the non-destructive shear test set by us. In combination with commercial laser lift-off technology, the GaN film was transferred to a silicon substrate.

The GaN film surface with a few areas of mottled dots after LLO, it was observed by an optical microscope that the GaN film ruptured and caused the solder overflowed from the bottom. Moreover, some unbroken areas of GaN film were bumpy. The phenomenon is presumed that the high temperature during the dissociation reaction causes the stress generated by partial liquefaction of the solder.

At present, the yield rate of our process is very low. Mostly, the wafers were separated from the junction of GaN and Silicon. It is presumed that due to the high temperature generated when laser scanning the sapphire substrate, the solder will be partially liquefied. If the wafer area is small (around 1 cm x 1 cm), the entire piece of solder will liquefy and move. This explains why manufacturers do not have this problem when dealing with 2" wafers laser lift-off process.

[1] 郭子菱，「LED 照明市場發展近況與趨勢」，光連雙月刊，第22-28頁 (2010)
[2] M. Osigbemeh, M. Onuu, O. Asaolu “Design and development of an improved traffic light control system using hybrid lighting system” Journal of traffic transportation Engineering, Vol. 4, No. 1, pp. 88-95 (2017)
[3] 潘錫明，「認識發光二極體」，科學發展月刊，第6-11頁 (2009)
[4] S. Nakamura, M. Senoh, and T. Mukai “High‐power InGaN/GaN double‐heterostructure violet light emitting diodes” Appl. Phys. Lett., Vol. 62, pp. 2390-2392 (1993)
[5] E. Fred. Schubert “Light Emitting Diode” Cambridge University Press, New York (2006)
[6] T. Matsuoka, H. Okamoto, M. Nakao, H. Harima, E. Kurimoto “Optical bandgap energy of wurtzite InN” Appl. Phys. Lett., Vol. 81, No. 3, pp. 1246-1248 (2002)
[7] G. Bhuiyan, K. Sugita, K. Kasashima, A. Hashimoto, A. Yamamoto, and V. Y. Davydov “Single-crystalline InN films with an absorption edge between 0.7 and 2 eV grown using different techniques and evidence of the actual band gap energy” Appl. Phys. Lett., Vol. 84, p. 452 (2004)
[8] Johnson, W. C., Parsons, J. B., Crew, J. Phys. Chem., Vol. 36, pp 2651–2654 (1932)
[9] Maruska, H. P. and Tietjen “The preparation and properties of vapor-deposited single-crystalline GaN” Appl. Phys. Lett., Vol. 15, p. 327 (1969)
[10] Pankove, J. I., Miller E. A. and Berkeyheiser “GaN Electroluminescence Diodes” RCA Review, Vol. 32, p. 383 (1971)
[11] H. P. Maruska, W. C. Rhines, and D. A. Stevenson “Preparation of Mg-doped GaN diodes exhibiting violet electroluminescence” Mat. Res. Bull., Vol. 7, pp. 777-781 (1972)
[12] S.Yoshida, S. Misawa, S. Gonda “Epitaxial growth of GaN/AlN heterostructures” J. Vac. Sci. Technol. B 1, 250. (1983)
[13] H. Amano, M. Kito, K. Hiramatsu, and I. Akasaki “P-Type Conduction in Mg-Doped GaN Treated with Low-Energy Electron Beam Irradiation (LEEBI)” Jpn. J. Appl. Phys. , Vol. 28, pp. L2112-L2114 (1989)
[14] S. Nakamura “Laser Deposition of AlN Thin Films on InP and GaAs” Jpn. J. Appl. Phys. , Vol. 30, p. L1750 (1991)
[15] I. Akasaki, H.Amano, K. Koide, and K. Manabe “GaN based UV/blue light-emitting devices” Inst. Phys. Conf. Ser., Vol.129, pp.851-856 (1992)
[16] R. D. Dupuis, and M. R. Krames “History, Development, and Applications of High-Brightness Visible Light-Emitting Diodes” Journal of Lightwave Technology, Vol. 26, No. 9, pp.1154-1171 (2008)
[17] S. Nakamura, M. Senoh, S.-i. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, et al. “Violet InGaN/GaN/AlGaN-Based Laser Diodes with an Output Power of 420 mW” Jpn. J. Appl. Phys. , Vol. 37, pp. L627-L629 (1998)
[18] 牛振儀，「藉著電漿處理濕式蝕刻圖案化藍寶石基板提升氮化鎵發光二極體之效能」，國立交通大學碩士論文，第8頁 (2012)
[19] M. K. Kelly, O. Ambacher, B. Dahlheimer, G. Groos, R. Dimitrov, H. Angerer, and M. Stutzmann., Appl. Phys. Lett., 69, 1749 (1996)
[20] W. S. Wong, T. Sands, and N. W. Cheung, Appl. Phys. Lett., 72, 599 (1998)
[21] Z. S. Luo, Y. Cho, V. Loryuenyong, T. Sands, N. W. Cheung, and M. C. Yoo “Enhancement of (In,Ga)N light-emitting diode performance by laser lift off and transfer from sapphire to silicon” IEEE Photonic Technology Letters, Vol. 14, No. 10, pp.1400-1402 (2002)
[22] B. S. Tan, S. Yuan, and X. J. Kang, , Appl. Phys. Lett., 84, 2757 (2004)
[23] Y. S. Wu, J. H. Cheng, W. C. Peng, Hao Ouyang, Appl. Phys. Lett., 90, 251110 (2007)
[24] S. Farrens “Metal Based Wafer Level Packaging” SUSS Micro. Tec.
[25] 唐仁政 田荣璋，「二元合金相图及中间相晶体结构」，中南大学出版社 (2009)
[26] 黃振東，｢淺談發光二極體散熱材料與元件｣，工業材料雜誌，Vol.281，第73-83頁 (2010)
[27] K. R. Krames et al. “High-Brightness AlGaInP Light-Emitting Diodes” Proc. SPIE, Vol. 3938, No. 2 (2000)
[28] C. Kittel “Introduction to Solid State Physics” John Wiley Press, Chap.8. (1996)
[29] S.O.Kasap “Optoelectronics and Photonics: Principles and Practices” (2nd Edition) Pearson Education, New Jersey (2001)
[30] E. Fred. Schubert “Light Emitting Diode” Cambridge University Press, U.K (2003)
[31] Pierre Gibart, Rep. Prog. Phys. 67, 667 (2004)
[32] T. Fujii, Y. Gao, R. Sharma, E. L. Hu, S. P. DenBaars, and S. Nakamuraa, Appl. Phys. Lett., 84, 855 (2004)
[33] Chun-Fu Tsai, Yan-Kuin Su, Chun-Liang Lin, Jpn. J. Appl. Phys. , 51, 01AG04 (2012)
[34] S. J. Chang, W. S. Chen, Y. C. Lin, C. S. Chang, T. K. Ko, Y. P. Hsu, C. F. Shen, J. M. Tsai, and S. C. Shei, IEEE Trans. Adv. Packaging, 29, 403 (2006)
[35] J. H. Cheng, Y. C. Sermon Wu, W. C. Liao, and B. W. Lin, Appl. Phys. Lett., 96, 051109 (2010)
[36] Lumileds Lighting, http://www.lumileds.com
[37] M. R. Krames, M. Ochiai-Holcomb, G. E. Hofler, 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 “High power truncated pyramid (Al0.5Ga1-x)0.5In0.5P/GaP light emitting diodes exhibiting >50% external quantum efficiency” Appl. Phys. Lett. , 75, 2365 (1999)
[38] LEDinside，｢淺談影響LED元件熱阻的因素｣ (2009)
[39] 楊士賢，｢LED背光照明與散熱技術｣，科技網 (2010)
[40] S. Grzanka, G. Franssen, G. Targowski, K. Krowicki, T. Suski, R. Czernecki, P. Perlin, and M. Leszczyński “Role of the electron blocking layer in the low-temperature collapse of electroluminescence in nitride light-emitting diodes” Appl. Phys. Lett., Vol. 90, pp. 103507 (2007)
[41] Strategies in light (2003)
[42] M. Y. Hsieh, C. Y. Wang, L. Y. Chen, T. P. Lin, M. Y. Ke, Y. W. Cheng, Y. C. Yu, C. P. Chen, D. M. Yeh, C. F. Lu, C. F. Huang, C. C. Yang, and J. J. Huang “Improvement of External extraction efficiency in GaN-based LEDs by SiO2 nanosphere lithography” IEEE Electron Device Lett., Vol. 29, pp. 658-660 (2009)
[43] T. Fujii, Y. Gao, R. Sharma, E. L. Hu, S. P. Den Baars, and S. Nakamura “Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening” Appl. Phys. Lett., Vol. 84, pp. 855-858 (2004)
[44] S. Nakamura, T. Mukai, M. Senoh, & N. Iwasa “Thermal Annealing Effects on P-Type Mg-Doped GaN Films” Jpn. J. Appl. Phys. , 31, 139-142 (1992)
[45] H. Jiang, T. Egawa, H. Ishikawa “AlGaN solar-blind Schottky photodiodes fabricated on 4H-SiC” IEEE Photon. Technol. Lett., 18(12), 1353-1355 (2006)
[46] J. P. Shim, S. R. Jeon, Y. K. Jeong, D. S. Lee “Improved Efficiency by Using Transparent Contact Layers in InGaN-Based p-i-n Solar Cells” IEEE Electron Device Lett., 31(10), 1140-1142 (2010)
[47] 黃冠賓，藉由晶圓接合從藍寶石基板剝離氮化鎵技術，交通大學材料科學與工程學系碩士論文 (2013)
[48] Q. Y. Tong, U. Gosele, and S. Electrochemical “Semiconductor wafer bonding: science and technology” John Wiley, p. 18 (1999)
[49] S. Farrens “Wafer Level Packaging: Balancing Device Requirements and Materials Properties” Pan Pacific Microelectronics Symposium, 22-24 (2008)
[50] V. Dragoi “Adhesive Wafer Bonding for MEMS Applications” Proceedings of SPIE, 5116, 160-167 (2003)
[51] M. Wiemer “Wafer Bonding with BCB and SU-8 for MEMS Packaging” Electronics System Integration Technology Conference, 2, 1401-1405 (2006)
[52] 張家豪，共濺鍍鋁鍺薄膜之接合特性研究，中央大學化學工程與材料工程學研究所碩士論文 (2013)
[53] Q. T. Tong and U. Gösele“Semiconductor wafer bonding：recent developments”Mater. Chem. and phys., 37 (1994)
[54] J. Haisma, and G. Spierings, Mater. Sci. Eng. R-Rep, 37, p.1 (2002)
[55] 維基百科，覆晶技術，http://zh.wikipedia.org
[56] Bo-Ying Wu “The Optical and Electrical Characteristics of GaN-Based Light-Emitting Diodes by Laser Lift Off” (2012)
[57] 張棋傑，氮化鎵垂直共振腔面射型雷射與發光二極體之製造與特性量測，國立台灣科技大學電子工程所碩士論文 (2015)
[58] 黃祈升，用藍寶石基板的氮化鎵元件之封裝與高反射鍍膜，國立台灣科技大學電子工程所碩士論文 (2018)
[59] K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, Y. Imada, M. Kato, T. Taguchi, Jpn. J. Appl. Phys. , 40, L583 (2001)
[60] 吳耀庭，｢圖案化藍寶石基板壓印材料技術發展｣，材料世界網 (2016)
[61] 鄭季豪，高亮度發光二極體效能之提昇―針對雷射剝離損傷機制與圖形化藍寶石基板之研究，交通大學材料科學與工程學系博士論文 (2013)
[62] Y.P. Hsu, S.J. Chang, Y.K. Su, J.K. Sheu, C.H. Kuo, C.S. Chang and S.C. Shei “ICP etching of sapphire substrates” Opt. Mater., 27, 1171 (2005)