隨著固態照明的演進，以發光二極體 (LEDs) 取代傳統照明的瓶頸主要在於提升亮度與有效的熱管理等方面。本論文以溼蝕刻得到的微織狀銦錫氧化物表面來增加光取出，取代感應耦合電漿 (ICP) 的表面粗化處理，將之應用在氮化鎵發光二極體得到光電特性的改善。
至於熱管理，一般對於氮化鎵發光二極體來說，雷射剝離技術是最常見改善散熱的製程，其後不論是以晶圓鍵合或是以電鍍方式製作金屬基板，其導熱率將遠優於藍寶石基板。
本論文亦探討垂直式氮化鎵發光二極體，並結合先前提到的微織狀銦錫氧化物以改善光電特性。在以KrF準分子雷射剝離氮化鎵發光二極體的藍寶石基板之前，以電鍍技術於藍寶石另一側沉積厚銅，最後成功製作出銅基板的垂直式氮化鎵發光二極體。目前得到的較佳製作方式，是在掛鍍電鍍銅進行之前，先用厚膜光阻遮擋切割走道，再進行電鍍銅製程，如此就可避開銅基板的切割問題。

With the development of solid-state lighting, the chief bottlenecks of replacing traditional lamps with light emitting diodes (LEDs) were enhancements in luminance and effective thermal management. In this paper, we increase light extraction efficiency with micro-textured indium tin oxide by wet etching, instead of surface-roughening treatment by ICP. Applying this technique to traditional GaN LEDs, we get improvements in optical and electrical characteristics.
As for thermal management, generally speaking, for GaN LEDs, laser lift-off technique is the most common process for improving heat dissipation, hereafter, no matter the fabrication of metal substrate is wafer bonding or electroplating, the thermal conductivity of metal will be much better than that of original sapphire substrate.
The vertical GaN LEDs will be discussed in this paper, combining with micro-textured indium tin oxide above mentioned to improve the optical and electrical properties of vertical GaN LEDs. Before lifting off sapphire substrates of GaN LEDs by KrF excimer laser, we employ the electroplating technique to deposit thick copper layer on the other side of sapphire substrate, and finally, the vertical GaN LEDs with copper substrates were fabricated successfully. To avoid dicing problems of copper substrates, separating each chip by defining thick photoresist on pitch between chips before rack copper electroplating is the better process in our experiments at present.

[1] M. G. Craford, “Nanoscience and Solid State
Lighting,” presented at Department of Energy
Nanosummit, Washington D.C., 2004.
[2] G. B. Stringfellow and M. G. Craford, “High
Brightness Light Emitting Diodes,” Academic Press,
San Diego, 1997.
[3] H. J. Round, “A Note on Carborundum,” Electrical
World, vol. 49, p. 309, 1907.
[4] J. Nishizawa, and K. Suto, “Minority-carrier lifetime
measurements of efficient GaAlAs p-n
heterojunctions,” J. Appl. Phys., vol. 48, pp. 3484-
3495, 1977.
[5] M. R. Krames, “High-power truncated-inverted-pyramid
(AlxGa1–x)0.5In0.5P/GaP light-emitting diodes
exhibiting > 50 external quantum efficiency,” Appl.
Phys. Lett., vol. 75, pp. 2365-2367, 1999.
[6] H. P. Maruska and J. J. Tietjen, “The preparation and
properties of vapor-deposited single-crystal-line
GaN,” Appl. Phys. Lett., vol. 15, pp. 327-329, 1969.
[7] Hiroshi Amano, Masahiro Kito, Kazumasa Hiramatsu and
Isamu Akasaki, “P-type conduction in Mg-doped GaN
treated with low-energy electron beam irradiation
(LEEBI),” Jpn. J. Appl. Phys., Part2, vol. 28, pp.
L2112-L2114, 1989.
[8] Shuji Nakamura, Senoh M. and Mukia T.,“P-GaN/n-
InGaN/GaN double-heterostructure blue-light-emitting
diodes,” Jpn. J. Appl. Phys., vol. 32, pp. L8-L11,
1993.
[9] S. Nakamura, M. Senoh, N. Iwasa, S. Nagahama,
T.Yamada, T. Mukai, “Superbright green InGaN single-
quantum-well-structure light-emitting diodes,” Jpn.
J. Appl. Phys., vol. 34, pp. L1332-L1335, 1995.
[10] C. R. Miskey, M.K. Kelly, O. Ambacher, M. Stutzmann,
“Freestanding GaN-substrates and devices,” Phys.
Stat. Sol., vol. 6, pp. 1627-1650, 2003.
[11] M. K. Kelly, O. Ambacher, R. Dimitrov, H. Angerer, R.
Handschuh, M. Stutzmann, “Laser-processing for
patterned and free-standing nitride films,”
Materials Research Society Symposium Proceedings,
vol. 482, Nitride Semiconductors, pp. 973-978, 1997.
[12] W. S. Wong, Y. Cho, E.R. Weber, T. Sands, K. M. Yu,
J. Kruger, A. B. Wengrow, N. W. Cheng , “Structural
and optical quality of GaN/metal/Si heterostructures
fabricated by excimer laser lift-off,” Appl. Phys.
Lett., vol. 75, pp. 1887-1889, 1999.
[13] N. W. Cheung, T. D. Sands, W. S. Wong, US patent
number 6071795, Jun. 6th, 2000.
[14] B. S. Tan, S. Yuan, and X. J. Kang, “ Performance
enhancement of InGaN light-emitting diodes by laser
lift-off and transfer from sapphire to copper
substrate,” Appl. Phys. Lett., vol. 84, pp. 2757-
2759, 2004.
[15] J. T. Chu, H. W. Huang, C. C. Kao, W. D. Liang, F. I.
Lai, C. F. Chu, H. C. Kuo and S. C. Wang,“
“Fabrication of large-area GaN-based light-emitting
diodes on Cu substrate,” Jpn. J. Appl. Phys., vol.
44, pp. 2509-2511, 2005.
[16] S. J. Wang, T. M. Chen, K. M. Uang, S. L. Chen, T. S.
Hsiao, S. C. Chang, H. Y. Kuo, and B. W. Liou, “A
vertical-structured Ni/GaN schottky barrier diode
using electroplating nickel substrate,” Jpn. J.
Appl. Phys., vol. 45, pp. L555-L558, 2006.
[17] R. H. Horng, C. E. Lee, S. C. Hsu, S. H. Huang, C. C.
Wu, C. Y. Kung, and D. S. Wuu, “High-power GaN light-
emitting diodes with patterned copper substrates by
electroplating,” Phys. Stat. Sol., vol. 201, pp.
2786-2790, 2004.
[18] M. Alexe and U. Gösele, Wafer Bonding Application and
Technology, Springer, Berlin, 2004.
[19] J. Arokiaraj, S. Tripathy, S. Vicknesh, and A. Raman,
“Realization of freestanding InP membranes on Si by
low-temperature wafer bonding and stress analysis
using micro-Raman spectroscopy,” Appl. Phys. Lett.,
vol. 88, p. 221901, 2006.
[20] W. S. Wong, T. Sands, N. W. Cheung, M. Kneissl, D. P.
Bour, P. Mei, L. T. Romano, and N. M. Johnson,
“InxGa1–xN light emitting diodes on Si substrates
fabricated by Pd–In metal bonding and laser lift-
off,” Appl. Phys. Lett., vol. 77, pp. 2822-2824,
2000.
[21] E. Fred Schubert, “Light Emitting Diodes and Solid-
state Lighting,” HANDBOOK.
[22] S. Nakamura, T Mukai, and M. Senoh, “Candela-class
high-brightness InGaN/AlGaN double-heterostructure
blue-light-emitting diodes,” Appl. Phys. Lett., vol.
64, pp. 1687-1689, 1994.
[23] S. Keller, B. P. Keller, Y. F. Wu, B. Heying, D.
Kapolnek, J. S. Speck, U. K. Mishra, and S. P.
DenBaar, “Influence of sapphire nitridation on
properties of gallium nitride grown by metalorganic
chemical vapor deposition,” Appl. Phys. Lett., vol.
68, pp. 1525-1527, 1996.
[24] H. Amono, 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, pp. 353-355, 1986.
[25] S. Nakamura, “GaN growth using GaN buffer layer,”
Jpn. J. Appl. Phys., vol. 30, pp. L1705-L1707, 1991.
[26] B. Beaumont, Ph. Vennéguès, P. Gibart, “Epitaxial
lateral overgrowth of GaN,” Phys. Stat. Sol., vol.
227, pp. 1-43, 2001.
[27] 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, pp. L583-
L585, 2001.
[28] S. J. Chang, Y. C. Lin, Y. K. Su, C. S. Chang, T. C.
Wen, S. C. Shei, J. C. Ke, C. W. Kuo, S. C. Chen, C.
H. Liu, “Nitride-based LEDs fabricated on patterned
sapphire substrates,” Solid-State Electronics, vol.
47, pp. 1539–1542, 2003.
[29] S. Nakamura, T. Mukai, M. Senoh, N. Iwasa, “Thermal
annealing effects on p-type Mg-doped GaN films,”
Jpn. J. Appl. Phys., vol. 31, pp. L139-L142, 1992.
[30] J. S. Jang, I. S. Chang, H. K. Kim, T. Y. Seong, S.
Lee, and S. J. Park, “Low-resistance Pt/Ni/Au ohmic
contacts to p-type GaN,” Appl. Phys. Lett., vol. 74,
pp. 70-72, 1999.
[31] J. K. Ho, C. S. Jong, C. C. Chiu, C. N. Huang, C. Y.
Chen, and K. K. Shih, “Low-resistance ohmic contacts
to p-type GaN,” Appl. Phys. Lett., vol. 74, pp. 1275-
1277, 1999.
[32] J. K. Sheu, Y. K. Su, G. C. Chi, P. L. Koh, M. J.
Jou, C. M. Chang, C. C. Liu, and W. C. Hung, “High-
transparency Ni/Au ohmic contact to p-type GaN,”
Appl. Phys. Lett., vol. 74, pp. 2340-2342, 1999.
[33] T. Maeda, Y. Koide, and M. Murakami, “Effects of NiO
on electrical properties of NiAu-based ohmic contacts
for p-type GaN,” Appl. Phys. Lett., vol. 75, pp.
4145-4147, 1999.
[34] Z. Z. Chen, Z. X. Qin, Y. Z. Tong, X. D. Hu, T. J.
Yu, Z. J. Yang, X. M. Ding, Z. H. Li, and G. Y.
Zhang, “Thermal annealing effects on Ni/Au contacts
to p type GaN in different ambient,” Mater. Sci.
Eng. B, vol. 100, pp. 199-203, 2003.
[35] B. Liu, E. Lambers, W. B. Alexander, and P. H.
Holloway, “Effects of a Ni cap layer on transparent
Ni/Au ohmic contacts to p-GaN,” J. Vac. Sci.
Technol. B, vol. 20, pp. 1394-1401, 2002.
[36] 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,” Appl. Phys. Lett., vol 74,
pp. 3930-3932, 1999.
[37] R. H. Horng, D. S. Wuu, Y. C. Lien, and W. H. Lan,
“Low-resistance and high-transparency Ni/indium tin
oxide ohmic contacts to p-type GaN,” Appl. Phys.
Lett., vol. 79, pp. 2925-2927, 2001.
[38] C. H. Kuo, S. J. Chang, Y. K. Su, R. W. Chuang, C. S.
Chang, L. W. Wu, W. C. Lai, J. F. Chen, J. K. Sheu,
H. M. Lo, and J. M. Tsai, “Nitride-based near-
ultraviolet LEDs with an ITO transparent contact,”
Mater. Sci. Eng. B, vol. 106, pp. 69-72 , 2004.
[39] T. K. Lin, S. J. Chang, Y. K. Su, Y. Z. Chiou, C. K.
Wang, C. M. Chang, and B. R. Huang, “ZnSe
homoepitaxial MSM photodetectors with transparent ITO
contact electrodes,” IEEE Trans. Electron Devices,
vol. 52, pp. 121-123, 2005.
[40] R. H. Horng, Y. C. Lien, W. C. Peng, D. S. Wuu, C. Y.
Tseng, C. H. Seieh, M. F. Huang, S. J. Tsai, and J.
S. Liu, “High-Brightness Wafer-Bonded Indium-Tin
Oxide/Light-Emitting Diode/Mirror/Si,” Jpn. J. Appl.
Phys., Part 2, vol. 40, pp. 2747-2751, 2001.
[41] S. J. Wang, S. L. Chen, K. M. Uang, W. C. Lee, T. M.
Chen, C. H. Chen, and B. W. Liou, “The use of
transparent conducting indium-zinc oxide film as a
current spreading layer for vertical-structured high-
power GaN-based light-emitting diodes,” IEEE
Photon. Technol. Lett., vol. 18, pp.1146-1148, 2006.
[42] C. J. Tun, J. K. Sheu, B. J. Pong, M. L. Lee, M. Y.
Lee, C. K. Hsieh, C. C. Hu, and G. C. Chi ,
“Enhanced light output of GaN-based power LEDs with
transparent Al-doped ZnO current spreading layer,”
IEEE Photon. Technol. Lett., vol. 18, pp. 274-276,
2006.
[43] E. Fred Schubert, Light-Emitting Diodes, Cambridge
University, Press 2006.
[44] 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,” Appl. Phys. Lett., vol.78,
pp. 3265-3267, 2001.
[45] T. Nishida, H. Saito, and N. Kobayashi, “Efficient
and high-power AlGaN-based ultraviolet light-emitting
diode grown on bulk GaN,” Appl. Phys. Lett., vol.
79, pp. 711- 712, 2001.
[46] I. Schnitzer, E. Yablonovitch, C. Caneau, T. J.
Gmitter, and A. Scherer, “30% external quantum
efficiency from surface textured, thin-film light-
emitting diodes,” Appl. Phys. Lett., vol. 63,
pp. 2174-2176, 1993.
[47] H. W. Huang, C. C. Kao, J. T. Chu, H. C. Kuo, S. C.
Wang, and C. C. Yu, “Improvement of InGaN-GaN light-
emitting diode performance with a nano-roughened p-
GaN surface,” IEEE Photon. Technol. Lett., vol. 17,
pp. 983-985, 2005.
[48] D. W. Kim, H. Y. Lee, M. C. Yoo, and G. Y. Yeom,
“Highly efficient vertical laser-liftoff GaN-based
light-emitting diodes formed by optimization of the
cathode structure,” Appl. Phys. Lett., vol. 86,
p. 052108, 2005.
[49] 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, pp. 855-857, 2004.
[50] C. C. Kao, H. C. Kuo, H. W. Huang, J. T. Chu, Y. C.
Peng, Y. L. Hsieh, C. Y. Luo, S. C. Wang, C. C. Yu,
and C. F. Lin, “Light-output enhancement in a
nitride-based light-emitting diode with 22˚ undercut
sidewalls,” IEEE Photon. Technol. Lett., vol. 17,
pp. 19-21, 2005.
[51] J. J. Wierer, M. R. Krames, J. E. Epler, N. F.
Gardner, and M. G. Craford, J. R. Wendt, J. A.
Simmons and M. M. Sigalas, “InGaN/GaN quantum-well
heterostructure light-emitting diodes employing
photonic crystal structures,” Appl Phys Lett., vol.
84, pp. 3885-3887, 2004.
[52] D. S. Wuu, W. K. Wang, W. C. Shih, R. H. Horng, C. E.
Lee, W. Y. Lin, and J. S. Fang, “Enhanced output
power of near-ultraviolet InGaN–GaN LEDs grown on
patterned sapphire substrates,” IEEE Photon.
Technol. Lett., vol. 17, pp. 288-290, 2005.
[53] J. O. Song, D. S. Leem, J. S. Kwak, O. H. Nam, Y.
Park, and T. Y. Seong, “Low resistance and
reflective Mg-doped indium oxide-Ag ohmic contacts
for flip-chip light-emitting diodes,” IEEE Photon
Technol. Lett., vol. 16, pp. 1450-1452, 2004.
[54] J. O. Song, W. K. Hong, Y. Park, J. S. Kwak, and T.
Y. Seong, “Low-resistance Al-based reflectors for
high-power GaN-based flip-chip light-emitting
diodes,” Appl. Phys. Lett., vol. 86, p. 133503, 2005.
[55] W. S. Wong, T. Sands, and N. W. Cheung, “Damage-free
separation of GaN thin films from sapphire
substrates,” Appl. Phys. Lett., vol. 72, pp. 599-
601, 1998.
[56] C. F. Chu, F. I. Lai, J. T. Chu, C. C, Yu, C. F. Lin,
H. C. Kuo, and S. C. Wang, “Study of GaN light-
emitting diodes fabricated by laser lift-off
technique,” J. Appl. Phys., vol. 95, pp. 3916-3922,
2004.
[57] M. K. Kelly, O. Ambacher, B. Dahlheimer, G. Groos, R.
Dimitrov, H. Angerer, and M. Stutzmann, “Optical
patterning of GaN Films,” Appl. Phys. Lett., vol.
69, pp. 1749-1751, 1996.
[58] O. Ambacher, M. S. Brandt, R. Dimitrov, T. Metzger,
M. Stutzmann, A. Fischer , A. Miehr, A.
Bergmaier ,and G. Dollinger, “Thermal stability and
desorption of Group III nitrides prepared by metal
organic chemical vapor deposition,” J. Vac. Sci.
Technol. B, vol.14, pp. 3532-3542, 1996.
[59] William Sam Wong, “Integration of GaN Thin Films
with Dissimilar Substrate Materials by Wafer Bonding
and Laser Lift-off,” 1999.
[60] C. F. Chu, F. I. Lai, J. T. Chu, C. C. Yu, C. F. Lin,
H. C. Kuo, and S. C. Wang, “Study of GaN light-
emitting diodes fabricated by laser lift-off
technique,” J. Appl. Phys., vol. 95, pp. 3916-3922,
2004.
[61] L. Zilan, H. Xiaodong, C. Ke, N. Ruijuan, L. Xuhui,
Z. Xiaoping, Y. Tongjun, Z. Bei, C. Song, Y. Zhijian,
C. Zhizhong, and Z. Guoyi, “Preparation of GaN-based
cross-sectional TEM specimens by laser lift-off,”
Micron, vol. 36, pp. 281–284, 2005.
[62] D. Edelstein et al., “Full copper wiring in a sub-
0.25μm CMOS ULSI technology,” Proc. IEEE IEDM, pp.
773-776, 1997.
[63] S. P. Murarka, “Multilevel interconnections for ULSI
and GSI era,” Mater. Sci. Engin., R19, pp. 87-151,
1997.
[64] J. J. Kelly and A. C. West, “Copper deposition in
the presence of polyethylene glycol, ”J.
Electrochem. Soc., vol. 145, pp. 3472-3481, 1998.
[65] J. M. Shieh, S. C. Chang, B. T. Dai and M. S. Feng,
“Investigation of carrying agents on microstructure
of electroplated Cu films,” Jpn. J. Appl. Phys.,
vol. 41, pp. 6347-6350, 2002.
[66] K. H. Dietz, Circuitree, vol. 22, Feb 2000.
[67] T. P. Moffat, J. E. Bonevich, W. H. Huber, A.
Stanishevsky, D. R. Kelly, G. R. Stafford and D.
Josell, “Superconformal electrodeposition of copper
in 500-90 nm features,” J. Electrochem. Soc., vol.
147, pp. 4524-4535, 2000.
[68] D. Josell, D. Wheeler, W. H. Huber and T. P. Moffat,
“Superconformal electrodeposition in submicron
features,” Phys. Rev. Lett., vol. 87, p. 016102,
2001.
[69] T. P. Moffat, B. Baker, D. Wheeler and D. Josell,
“Accelerator aging effects during copper
electrodeposition,” Electrochem. Solid-State Lett.,
vol. 6, pp. C59-C62, 2003.
[70] M. Tan and J. N. Harb, “Additive behavior during
copper electrodeposition in solutions containing ,
PEG, and SPS,” J. Electrochem. Soc., vol. 150, pp.
C420-C425, 2003.
[71] A. Frank and A. J. Bard, “The decomposition of the
sulfonate additive sulfopropyl sulfonate in acid
copper electroplating chemistries,” J. Electrochem.
Soc., vol. 150, pp. C244-C250, 2003.
[72] F. C. Walsh, Trans. Inst. Metal Finish., vol. 70, p.
50, 1992.
[73] F. C. Walsh, Trans. Inst. Metal Finish., vol. 70, p.
95, 1992.
[74] R. H. Horng, C. C. Yang, J. Y. Wu, S. H. Huang, C. E.
Lee, and D. S.Wuu, “GaN-based light-emitting diodes
with indium tin oxide texturing window layers using
natural lithography,” Appl. Phys. Lett., vol. 86, p.
221101, 2005.
[75] S. J. Chang, C. F. Shen, W. S. Chen, C. T. Kuo, T. K.
Ko, S. C. Shei, J. K. Sheu, “Nitride-based light
emitting diodes with indium tin oxide electrode
patterned by imprint lithography,” Appl. Phys.
Lett., vol. 91, p. 013504, 2007.
[76] Chen-Fu Chu, Chang-Chin Yu, Hao-Chun Cheng, Chia-Feng
Lin and Shing-Chung Wang, “Comparison of p-side down
and p-side up GaN light-emitting diodes fabricated by
laser lift-off,” Jpn. J. Appl. Phys., Part 2, vol.
42, pp. L147–L150, 2003.