本研究利用有機金屬化學氣相沉積(MOCVD)系統，透過「氣-液- 固」機制及使用金當催化劑，成功地在溫度700oC下分別在藍寶石(脉-Al2O3)、矽基板和氮化鎵上成長氮化鎵的奈米線。我們將氮源由傳統MOCVD製程所使用的氨氣(NH3)改為第三丁基聯胺(tertiarybutylhydrazine, TBHy)來與三甲基鎵(trimethyl gallium, TMGa)反應成長一維之氮化鎵奈米線，探討不同的V/III原料供給比、金觸媒厚度、反應時間和材質不同的基材對成長氮化鎵奈米線的影響。
結果發現當成長溫度為700oC，V/III族原料供給比為53.2，以濺鍍法成長了3nm的金觸媒條件下，僅有在GaN基材上才能成長出筆直排列的氮化鎵奈米線，經由XRD分析發現成長方向為C平面的(0001)，其光激發螢光光譜(PL)測量發現奈米線峰值為364.7nm(3.4eV)半高寬為86meV，PL強度比二維的GaN磊晶膜強約39%，顯示基材的晶相特徵決定了成長出的氮化鎵奈米線結晶品質。
我們又利用自組裝製程以控制金核的密度與形態、製作可誘導直列式奈米柱成長的窗口(window)結構期望可得到筆直排列形貌，未來進一步應用在LED的發光元件上。

Vertically-aligned GaN nanorods were successfully grown on gold-coated α-Al2O3(001), Si(111) and GaN(002) substrates by metalorganic chemical vapor deposition (MOCVD). The GaN NWs growth temperature was lowered to 700oC using TBHy alternative to NH3. The precursors of Ga and N were TMGa and TBHy.
The diameter and length of GaN nanorods can be controlled by adjusting the V/III ratio, catalyst thickness, reaction time and different substrate. The surface morphology and optical characterization of the grown GaN nanowires were studied by field emission scanning electron micrscope(FE-SEM), photoluminescence(PL), Raman Spectrometer, X-ray diffraction(XRD).
A 3 nm-thick sputtered Au catalyst layer, after 700oC annealing, V/III ratio is 53.2, resulted in well vertically-aligned GaN nanorods growth on the GaN substrate. The PL spectra revealed sharp peaks at 364.7nm (3.4eV) with a full width at half maxium (FWHM) of 86meV. Photoluminescence measurement also showed the intensity of band edge emission was 39 % higher than that of the two-dimentional GaN thin film grown on α-Al2O3(001) substrate. respectively, indicating that the grown GaN nanowires were highly crytalline.
We try to use different catalyst seeding method, which gold nanoparticles catalyst are continuously self-assembled amine-terminated on 脉-Al2O3 substrate. The diameter and density of GaN nanowires can be controlled by adjusting the size and density of Au nanoparticles.

[1] S. M. Sze, “Semiconductor Devices Physics and Technology, ” 2nd edition, John Wiley & Sons, Inc.,( 2002).
[2] M. A. Khan and M. S. Shur, ”GaN based transisors for high temperature applications,” Material Science and Engineering B, Vol.46, pp.67-73(1997).
[3] H.M. Kim, Y.H. Cho and H. Lee, “High-Brightness Light Emitting Diodes Using Dislocation-Free Indium Gallium Nitride/Gallium Nitride Multiquantum-Well Nanorod Arrays,” Nano Letters, Vol. 4, No. 6, pp.1059-1062(2004).
[4] Y.B Tang, Z.H. Chen, H.S. Song and C.S. Lee, “Vertically Aligned p-Type Single-Crystalline GaN Nanorod Arrays on n-Type Si for Heterojunction Photovoltaic Cells,” Nano Letters, Vol.8, No.12, pp.4191-4195(2008).
[5] S. Nakamura and S. F. Chichibu, “Introduction to Nitride Semiconductor Blue Lasers and Light Emitting Diodes, ” CRC Press, New York (2000).
[6] 李亞儒、邱清華、郭浩中、盧廷昌、王興宗、林尚佑，「高效率二維氮化鎵藍光發光二極體陣列」，化合物半導體與光電技術雜誌，第二十四期，第32頁，2009。
[7] I. Ahmad, M. Holtz, N. N. Faleev and H. Temkin, “Dependence of the stress–temperature coefficient on dislocation density in epitaxial GaN grown on 脉-Al2O3 and 6H–SiC substrates,” J. Appl. Phys. , Vol. 95, No.4, pp.1692-1697（2004）.
[8] N. D. Bassim, M. E. Twigg, C. R. Eddy, Jr., J. C. Culbertson, M. A. Mastro, R. L. Henry, R. T. Holm, P. G. Neudeck, A. J. Trunek and J. A. Powell, “Lowered dislocation densities in uniform GaN layers grown on step-free (0001) 4H-SiC mesa surfaces, ” Appl. Phys. Lett., Vol.86, pp. 021902(2005).
[9] I. Nikitina, G. Mosina, Y. Melnik, A. Nikolaev and K. Vassilecski, Mater.Sci. Eng. B, Vol.61, pp.325-329(1999).
[10] I. Ahmad, M. Holtz, N. N. Faleev and H. Temkin, J. Appl. Phys.,Vol.95, pp.1692(2004).
[11] J. Bai, T. Wang, P. J. Parbrook, K. B. Lee and A. G. Cullis, J.Cryst.Growth.,Vol. 282, pp.290(2005).
[12] K. Lee and K. Auh, MRS Internet J. Nitride Semicond. Res., Vol.6, pp.9(2001).
[13] J. L. Rouviere, M. Arlery, B. Daudin, G. Feuillet and O. Briot, Mater.Sci. Eng. B, Vol. 50, pp.61(1997).
[14] S. Nakamura, M. Senoh and T. Mukai, “P-GaN / N-InGaN / N-GaN double-heterostructure blue-light-emitting diodes,” Jpn. J. Appl. Phys., Vol.32, pp. L8-L11(1993).
[15] W. Han, S. Fan, Q. Li and Y. Hu, Science,Vol.277, pp.1287(1997).
[16] G. S. Cheng, L. D. Zhang, Y. Zhu, T. Fei, and L. Li, Appl. Phys. Lett., Vol.75, pp.2455(1999).
[17] X. Duan, C. M. Lieber, J. Am. Chem. Soc., Vol.122, No.1, pp.188(2000).
[18] J. V. Smith, Geometrical and Structure Crystallography, Wiley, New York (1982).
[19] S. Nakamura, S. P. DenBaars, R. Sharma, E. L. Hu, R. Sharma, Y. Gao and T. Fujii, “Increase in the efficiency of GaN-based lighting-emitting diodes via surface roughening,” Appl. Phys. Lett., Vol. 84, No. 6, pp. 855-857 (2004).
[20] W. C. Peng and Y. S. Wu, “Enhanced performance of an InGaN-GaN light-emitting diode by roughening the undoped-GaN surface and applying a mirror coating to the sapphire substrate,” Appl. Phys. Lett., Vol. 88, No.18, pp. 181117 (2006).
[21] C. Huh, S. J. Park, E. J. Kang and K. S. Lee, “Improved light-output and electrical performance of InGaN-based light-emitting diode by microroughening of the p-GaN surface,” J. Appl. Phys., Vol. 93, No. 11, pp. 9383-9385 (2003).
[22] C. H. Chiu, T. C. Lu, H. W. Huang, C. F. Lai, C. C. Kao, J. T. Chu, C. C. Yu, H. C. Kuo, S. C. Wang, C. F. Lin and T. H. Hsueh, “Fabrication of InGaN/GaN nanorod light-emitting diodes with self-assembled Ni metal island,” Nanotechnology, Vol. 18, pp. 445201 (2007).
[23] M. C. Jeong, B. Y. Oh, M. H. Ham, S. W. Lee and J. M. Myoung, Small, Vol. 3, No. 4, pp. 568-572 (2007).
[24] H. M. Kim, Y. H. Cho, H. Lee, S. I. Kim, S. R. Ryu, D. Y. Kim, T. W. Kang and K. S. Chung , “High-brightness light emitting diodes using dislocation-free InGaN/GaN multiquantum-well nanorod arrays ,” Nano Letters, Vol. 4, No. 6, pp. 1059-1062 (2004).
[25] Y. B. Tang, X. H. Bo, C. S. Lee, H. T. Cong, H. M. Cheng, Z. H. Chen, W. J. Zhang, I. Bello and S. T. Lee, Adv. Mater., Vol.18, pp3515-3522(2008).
[26] Y. F. Zhang, Y. H. Tang, N. Wamg, D. P. Yu, C. S. Lee, I. Bello and S.T. Lee, Appl. Phys. Lett., Vol.72, pp.1835(1998).
[27] W. Q. Han, S. S. Fan, Q. Q. Li, B. L. Gu, X. B. Zhang and D. P. Yu, Appl. Phys. Lett., Vol.71, pp.2271(1997).
[28] Z. S. Wu, S. Z. Deng, N. S. Xu, Jian Chen, J. Zhou and Jun Chen, Appl. Phys. Lett.,Vol.80, pp.3829(2002).
[29] X. T. Zhou, N. Wang, H. L. Lai, H. Y. Peng, I. Bello, N. B. Wong, C. S. Lee, Appl. Phys. Lett., Vol.74, pp.3942(1999).
[30] C. C. Tang, S. S. Fan, H. Y. Dang, P. Li and Y. M. Liu, Appl. Phys. Lett.,Vol.77, pp.1961(2000).
[31] M. Yoshizawa, A. Kikuchi, M. Mori, N. Fujita and K. Kishino, Jpn.J. Appl. Phys., Vol.36, pp. L459 (1997).
[32] Y. H. Kim, J. Y. Lee, S. H. Lee, “Indium-related novel architecture of GaN nanorod grown by molecular beam epitaxy,” Chemical Physics Letters, Vol. 412, pp.454–458(2005).
[33] A. Wohlfart, A. Devi, E. Maile and R. A. Fisher, Chem. Commun.,Vol.9, pp. 998(2002).
[34] J. Khanderi, A. Wohlfart, H. Parala, A. Devi, J. Hambrock, A. Birkner and R. A. Fisher, J. Mater. Chem., Vol.13, pp. 1438(2003).
[35] Y. D. Wang, S. J. Chua, M. S. Sander, P. Chen, S. Tripathy and C. G. Fonstad, Appl. Phys. Lett., Vol.85, pp. 816(2004).
[36] J. Zhang, X. S. Peng, X. F. Wang and L. D. Zhang, Chemical Physics Letters, Vol.345, pp. 372(2001).
[37] H.M. Kim, T.W. Kang and K.S. Chung, “Nanoscale ultraviolet-light-emitting diodes using wide-bandgap Gallium Nitride nanorods,” Adv. Mater., Vol. 15, No. 7-8, pp. 567-569 (2003).
[38] H. M. Kim, D. S. Kim, D. Y. Kim, T. M. Kang, Y. H. Cho and K. S. Chung, “Growth and characterization of single-crystal GaN nanorods by hydride vapor phase epitaxy,” Appl. Phys. Lett., Vol. 81, No. 12, pp. 2193-2195 (2002).
[39] (a) N. Wang, Y. F. Zhang, Y. H. Tang, C. s. Lee and S.T. Lee, “SiO2-enhanced synthesis of Si nanowires by laser ablation,” Appl. Phys. Lett., Vol.73, No.26, pp. 3902-3904 (1998).
(b) R. Q. Zhang, Y. Liftshitz, and S. T. Lee, “Oxide– assisted growth of semiconducting nanowires,” Adv. Mater., Vol.15, No.7-8, pp. 635-640 (2003).
(c) S. T. Lee, Y. F. Zhang, N. Wang, Y. H. Tang, I. Bello and C. S.
Lee, “Semiconductor nanowires from oxides,” J. Mater. Res., Vol.14,
No.12, pp. 4503-4507 (1999).
[40] X. Wang, X. Sun, M. Fairchild and S. D. Hersee, “Fabrication of GaN nanowire arrays by confined epitaxy,” Appl. Phys. Lett., Vol. 89, pp. 233115 (2006).
[41] S. D. Hersee, X. Sun and X. Wang, “The controlled growth of GaN nanowires,” Nano Letters, Vol. 6, N0. 8, pp. 1808-1811 (2006).
[42] R. S. Wagner and W. C. Ellis, “Vapor-liquid-solid mechanism of single crystal growth,” Appl. Phys. Lett., Vol.4, pp. 89(1964).
[43] S. Amwlinckx, X. B. Zhang, D. Bernaerts, X. F. Zhang, V. Ivanov and J. B.Nagy, Science, Vol.265, pp. 635(1994).
[44] A. M. Morales and C. M. Lieber, “A laser ablation method for the synthesis of crystalline semiconductor nanowires,” Science, Vol. 279, pp. 208-211 (1998).
[45] H. Okamoto, P. R. Subramanian and Linda Kacprzak, Binary Alloy phase diagrams, ASM International, Materials Park.
[46] P. Yang and C.M. Lieber, J. Mater. Res.,Vol. 12, pp.2981(1997).
[47] L.X. Zhao, G.W. Meng, X.S. Peng, X.Y. Zhang and L.D. Zhang, Appl.Phys. A, Vol. 74, pp. 587(2002).
[48] H.P. Maruska and J.J. Tietjen, “The preparation and properties of vapor-deposited single-crystalline GaN,” Appl.Phys.Lett., Vol.15, pp.327-329(1969).
[49] J.J. Pankove, E.A Miller and J.E. Berkeyheiser, “GaN electroluminescent diodes, ” RCA Rev. ,Vol.32, pp. 383-392(1971).
[50] H.M. Manasevit, F.M. Erdmann and W.I. Simpson, “The use of metalorganics in the preparation of semiconductor materials, ” J.Electrochem.Soc., Vol.118, pp.1864-1868(1971).
[51] S. Yoshida, S. Misawa and S. Gonda, “ Improvements on the electrical and luminescent properties of reactive molecular beam epitaxially grown GaN films by using AlN-coated sapphire substrates, ” Appl.Phys.Lett., Vol.42, pp.427-429(1983).
[52] 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).
[53] S. Nakamura, “ GaN growth using GaN buffer layer,” Jpn.J.Appl.Phys., Vol. 30, pp.L1705-L1707(1991).
[54] S. Nakamura, T. Mukai, M. Senoh and N. Iwasa, “Thermal annealing effects on p-type Mg-doped GaN films, ” Jpn.J.Appl.Phys., Vol.31, pp.L139-L142(1992).
[55] S. Nakamura, M. Senoh, N. Iwasa and S. Nagahama, “High-brightness InGaN blue,green and yellow light-emitting diodes with quantum well structures,” Jpn.J.Appl.Phys., Vol. 34, pp.L797-L799(1995).
[56] S. Fujieda, M. Mizuta and Y. Matsumoto, “Growth characterization of low-temperature MOCVD GaN comparison between N2H4 and NH3,” Jpn. J. Appl. Phys., Vol. 26, No. 12, pp. 2067-2701 (1987).
[57] Z. Liu, R. T. Lee and G. B. Stringfellow, “Prolysis of tertiarybutylamine alone and with trimethylgallium for GaN growth,” J. Cryst. Growth, Vol. 191, pp. 1-7 (1998).
[58] E. Bourret-Courchesne, Q. Ye, D. W. Peters, J. Arnold, M. Ahmed, S. J. C. Irvine, R. Kanjolia, L. M. Smith and S. A. Rushworth, “Pyrolysis of dimethylhydrazine and its co-pyrolysis with triethylgallium,” J. Cryst. Growth, Vol. 217, pp.47-54 (2000).
[59] R. T. Lee and G. B. Stringfellow, “Pyrolysis of monomethylhydrazine for organometallic vapor-phase epitaxy (OMVPE) growth, ” J. Cryst. Growth, Vol. 204, pp.247-255 (1999).
[60] U.W. Pohl, K. Knorr, C. Moller, “Low-Temperature metalorganic vapor phase epitaxy(MOVPE) of GaN using Tertiarybutylhydrazine,” Jpn.J.Appl.Phys., Vol. 38, pp.L105-L107(1999).
[61] H. Y. Kwon, M. J. Shin, Y. J. Choi, J. Y. Moon, H. S. Ahn, S. N. Yi, S. Kim, D. H. Ha, S. H. Park, “Effects of temperature and carrier gas flow amount on the formation of GaN nanorods by the HVPE method,” J. Cryst. Growth, Vol.311, pp.4146-4151(2009).
[62] C.Y. Chang , S.J. Pearton , P.J. Huang , G.C. Chi ,H.T. Wang , J.J. Chen , F. Ren, K.H. Chen , L.C. Chen, “Control of nucleation site density of GaN nanowires,” Applied Surface Science, Vol. 253, pp.3196–3200(2007).
[63] Q. Li, J. R. Creighton and G.T. Wang , “The role of collisions in the aligned growth of vertical nanowires,” J. Cryst. Growth, Vol. 310, pp. 3706-3709 (2008).
[64] T. Kuykendall, P.J. Pauzauskie, Y. Zhang, J. Goldberger, D. Sirbuly, J. Denlinger and P. Yang, “Crystallographic alignment of high-density gallium nitride nanowire arrays,” Nature materials, Vol.3, pp.524-528(2004).
[65] C. C. Chen, C.C. Yeh, C.H. Chen, M. Y. Yu, H. L. Liu, J.J. Wu, K.H. Chen, L. C. Chen, J.Y. Peng and Y.F. Cheng, “Catalytic growth and characterization of Gallium Nitride nanowires,” J. Am. Chem. Soc., Vol. 123, No. 12, pp. 2791-2798 (2001).
[66] J. Zhang and L. Zhang, “Morphology and Raman scattering
spectrum of GaN nanowires embedded in nanochannels of template ,” Appl. Phys. ,Vol. 35, pp.1481–1485 (2002).
[67] B. Ha, S. H. Seo, C. S. Yoon, J. Yoo, G. C. Yi, C. Y. Park and C. J. Lee, “Optical and field emission properties of thin single-crystalline GaN nanowires,” J. Phys. Chem. B, Vol. 109, pp. 11095(2005).
[68] H. J. Choi, D. H. Kim, T. G. Kim, J. C. Lee and Y. M. Sung, “Various one dimensional GaN nanostructure formed by non-catalytic routes,” Journal of Electroceramics, Vol. 17. No. 17, pp. 221-225 (2006).
[69] T. S. Cheng, C. T. Foxon, G. B. Ren, J. W. Orton, Y. V. Melnik, I. P. Nikitina, A. E. Nikolaev, S. V. Novikov and V. A. Dmitriev, “Effects of substrate type on the characteristics of GaN epitaxial films grown by molecular beam epitaxy,” Semicond. Sci. Technol., Vol. 12, pp. 917-920 (1997).
[70] S. M. Lee, M. A. Belkhir, X. Y. Zhu and Y. H. Lee, “Electronic structures of GaN edge dislocation,” Phys. Rev. B, Vol. 61, No. 23, pp. 16033-16039 (2000).
[71] Y. J. Hsu, L. S. Hong, K. F. Huang and J. E. Tsay, “Low temperature metalorganic chemical vapor deposition of gallium nitride using dimethydrazine as nitrogen source,” Thin Solid Films, Vol. 419, pp. 33-39 (2002).
[72] P. W. Lee, T. R. Omstead, D. R. Mckenna and K. F. Jensen, “In situ mass spectroscopy and thermogravimetric studies of GaAs MOCVD gas phase and surface reactions”, J. Cryst. Growth, Vol. 85, pp. 165-174 (1987).