中文摘要：
近幾年來，量子點不論在理論上或製作上都引起了廣大的興趣，量子點引起大家興趣，因為他有很好的光特性以及元件特性，可運用在量子點雷射以及記憶元件上。量子點他在雷射上的優點主要是塔擁有低臨界電流以及對溫度敏感度低。
我們可以長出硒化鋅量子點在砷化鎵基板上，高密度量子點是1.3×109 /cm2在六族及二族流量比為16.7下所產生的，當六及二族流量比大於16.7或小於7.5都可大大的增加硒化鋅量子點密度.量子點造成硒化鋅波長藍移8 nm 至 15 nm .
高品質且和磷化鎵基板晶格常數幾乎匹配的ZnS0.81Se0.19磊晶層已經被成功的製造，使用EPMA檢測出硫的含量為0.81，X光分析可知其半高寬為720.2 arcsec，R-value為5.294%
我們也試著長Stranski-Krastanow mode 的量子點，將ZnSe量子點長在和磷化鎵基板晶格常數幾乎匹配的ZnS0.81Se0.19磊晶層上，分別長30秒至300秒，在30秒時，他有最大密度1.1×109 /cm2.

ABSTRACT
Recently, there has been an increasing interest in the fabrication and theory of self-assembled quantum dots (SAQD). Self-assembled quantum dots are of great interest because of good optical properties and device applications such as quantum dot lasers and memory device. The main merit of laser based on quantum dot is both the low threshold current density and low temperature sensitivite.
We can grow the ZnSe quantum dot on GaAs substrate. The maximum value of dots density is 1.3×109cm-2 at 16.7 of Ⅵ/Ⅱ ratio. The dots densities are increasing by the flow rate of DEZn and H2Se. When the Ⅵ/Ⅱ ratio are lager than 16.7 or smaller than 7.5 will lead to quantum dots increasing. The blue shift is from 8 nm to 15 nm by quantum confinement.
The high quality of ZnS0.81Se0.19 epilayers on GaP substrate are grown with DEZn, H2Se, H2S and H2 fixed at 2.4 sccm, 10 sccm, 10 sccm and 1 slm respectively, and prepared at 340℃ and 50 min. High quality ZnS0.81Se0.19:N epilayer which was lattice-matched to GaP substrate has been prepared. The FWHM of X-ray diffraction was 720.2 arcsec. Its R-value was 5.20%. Then we grow ZnSe quantum dots / ZnS0.81Se0.19/GaP. The largest density of quantum dots is 1.1×109 cm-2 at 30 s growth time.

CONTENTS
LIST OF FIGURES I
LIST OF TABLES IV

1. INTRODUCTION 1
1-1 Applications from Blue to Ultraviolet Light Emitting Devices 1
1-2 Promising Materials for Blue LEDs 2
1-2-1 SiC-based Blue LEDs 2
1-2-2 GaN-based Blue LEDs 3
1-2-3 ZnSe-based Blue LEDs 5
1-2-4 Developments of Organic Light Emitting Diodes 6
1-3 Developments of Ⅱ-Ⅵ Blue Light Emitting Devices 7
1-4 Motivations of ZnSe-based Epilayers Growth 9
1-5 Quantum Dots 12
1-6 Considerations of Substrates 14
1-6-1 Lattice Mismatch Problem 14
1-6-2 Thermal Mismatch Problem 15
1-6-3 Interdiffusion Problem 16
1-6-4 Selections of Substrates 16
1-7 Requirements of Low-Temperature Growth 18
1-8 Thermally Evaporated Transparent Conducting In2O3:Sn Film for Ohmic Contact 19

2. EXPERIMENTS 22
2-1 OMVPE Growth System 22
2-1-1 Cold Wall System and Single Hot Zone 22
2-1-2 Simplicity, Flexibility and Versatility 23
2-1-3 Halide-Free 23
2-1-4 Stoichiometry Easily Controlled 24
2-1-5 Low Temperature and Low Pressure Growth 24
2-1-6 Capability of Double Heterostructure 25
2-2 Components of OMVPE 25
2-2-1 Design of Growth Reactor 25
2-2-2 Reactant Gases Handling System 27
2-2-3 Heating System 28
2-2-4 Exhaust Disposal System 28
2-2-5 Safety Considerations 28
2-3 Substrate Preparation 29
2-4 ZnSe-based Epilayer Growth Procedures 31
2-5 Quality Evaluations of ZnSxSe1-x Epilayers 33
2-6 Components of Thermal Evaporator 34
2-7 Quality Evaluations of ITO Thin Films 34

3. RESULTS AND DISCUSSION 35
3-1 Growth of Binary ZnSe Epilayers on GaAs by LP-OMVPE 35
3-1-1 Epitaxial Growth of Binary ZnSe by LP-OMVPE 35
3-1-2 Uniformity 39
3-1-3 Optical Property 39
3-1-4 Surface Morphology 41
3-2 Growth of Binary ZnS Epilayers on GaP by LP-OMVPE 44
3-2-1 Epitaxial Growth of Binary ZnS by LP-OMVPE 44
3-2-2 Uniformity 46
3-2-3 Optical Property 47
3-2-4 Surface Morphology 47
3-3 Growth of Ternary ZnSxSe1-x Epilayers on GaP by LP-OMVPE 48
3-3-1 Epitaxial Growth of Ternary ZnSxSe1-x by LP-OMVPE 48
3-3-2 Uniformity 50
3-3-3 Crystallinity 50
3-3-4 Surface Morphology 51
3-4 Growth of ZnSe Quantum Dots on ZnSSe/GaP by MOVPE 51
3-4-1 Epitaxial Growth of Quantum dot structure by LP-OMVPE 52

FIGURES 56
TABLES 107
REFERENCES 111

Reference
[1] Compound Semicondutor, Volume Number 1, July August, 1995
[2] A. Suzuki, M. Ikeda, N. Nagao, H. Matsunami, and T. Tanaka, “Liquid-phase epitaxial growth of blue-light-emitting diodes”, J. Appl. Phys., vol 57. pp.4546-4550, 1976
[3] V. I. Levin, Y. M. Tairov, M. G. Travaxhdyan, F. Tsvekov and M.A. Chernov, Sov. Phys. Izv. 14, 830, 1987
[4] M. E. Lin, B. Sverdlov, and H. Morkoc, J. Appl. Phys. 74, 5038, 1993
[5] H. G. Grimmeiss and B. Monemar, J. Appl. Phys. 41, 4054, 1970
[6] I. Akasaki, H. Amano, Y. Koide, K. Hiramatsu, and N. Sawaki, J. Cryst. Growth., 98, 209, 1989
[7] H. Amano, M. Kito, K. Hiramatsu, and I. Akasaki, Jpn. J. Appl. Phys. 28, L2112, 1989
[8] S. Nakamura, Takashi Mukai, M. Senoh and N. Iwasa, "Thermal annealing effect on p-type Mg-doped GaN films", Jpn. J. Appl. Phys.,31, L139, 1992
[9] S. Nakamura, M. Senoh and T. Mukai, Appl. Phys. Lett., 62, 2391, 1993
[10] Y. Chen, X. Liu, E. WwFwe, E. D. Bourret, and J. Washhurn, "Structures and electronic properties of misfit dislocations", Appl. Phys. Lett. 65, 549, 1994
[11] J. Wu, J. M. Depuydt, G. M. Haugen, G. E. Hofler, M. A. Hause, H. Cheng, S. Guha, "Wide band gap MgZnSSe grown on (001) GaAs by molecular beam epitaxy", Appl. Phys. Lett. 66 (25), 3462, 1995
[12] J. M. Gaines, R. R. Drenten, K. W. Haberern, T. Marshall, and J. Petruzzello, "Blue-green injection lasers containing pseudomorphic ZnxMg1-xSySe1- y cladding layers and operating up to 394 K", Appl. Phys. Lett. 62 (20), 2462, 1993
[13] L. Salamanca-Riba and L. H. Kuo, "Observation of [100] and [010] Dark Line Defects in Optically Degraded ZnSSe-Based LEDs by Transmission Electro Mircoscopy", Journal of Electronic Materials, vol 25, No.2, pp.239, 1996
[14] K. Nakano, A. Ishibashi, Proc. Int. Conf. On Solid State Devices and Materials, Yokohama, vol. 6, 1996
[15] M. Heuken, H. Sollner, W. Taudt, S. Lampe, H. Hamadeh, "Metaloraganic chemical vapor epitaxy and doping of ZnMgSSe heterostructures for blue emitting devices", J. Cryst. Growth 170 (1997) pp.30-38
[16] R. M. Park M. B. Troffer, C. M. Rouleau, J. M. DePutdt and M. A. Haase, Appl. Phys. Letters 57, 2127, 1990
[17] M. A. Haase, J. Qiu, J. M. DePuydt, and H. Cheng,"Blue-green laser diodes', Appl. Phys. Lett. 59, 1272, 1991
[18] I. W. Tao, Y. Wang, M. Jurkovic, and W. I. Wang," ZnMgSeS/ZnSSe/CdZnSe strained quantum well lasers grown on (511)A orientation", J. Appl. Phys. 78, 2851, 1995
[19] Akira Ishibashi, Yoshifumi Mori, " Advances in blue laser diodes ", J. Cryst. Growth 138(1994) pp.677-685.
[20] P. Uusimaa, K. Rakennus, A. Salokatve, and M. Pessa, "Molecular beam epitaxy growth of MgZnSSe/ZnSSe Bragg mirrors controlled by in situ optical reflectometry", Appl. Phys. Lett. 67, 2197, 1995
[21] H. Jeon, V. Kozlov, P. Kellkar, and A. V. Nurmiloko, "Room-temperature optically pumped blue-green vertical cavity surface emitting laser", Appl. Phys. Lett. 67, 1668, 1995
[22] L. Salmanca-Riba and L. H. Kuo, "Observation of [100] and [010] Dark Line Defects in Optically Degraded ZnSSe-Based LEDs by Transmission Electro Mircoscopy", Journal of Electronic Materials, vol 25, No.2, pp.239, 1996
[23] See: J. Cryst. Growth 138 (1994).
[24] H. Okuyama, K. Nakano, T. Miyajima and K. Akimoto, "Epitaxial growth of ZnMgSSe on GaAs substrate by molecular beam epitaxy", Jpn. J. Appl. Phys. 30, 1620, 1991
[25] M. K. Lee, M. Y. Yeh, S. J. Guo, and H. D Huang, “Nitrogen Doped ZnSe with Selenium Rich Growth by Low-pressure organometallic Chemical Vapor Deposition”, J. Appl. Phys
[26] S. Fujita, T. Yodo and A. Sasaki, J. Cryst. Growth. 72, 27, 1985
[27] Shizuo Fujita, Shigeo Fujita, “Photo-assisted metalorganic vapor phase epitaxial growth of wide-gap Ⅱ/Ⅵ semiconductors”, J. Cryst. Growth, 117(1992) 67-74
[28] J. C. Bouley, P. Blanconnier, A. Herman, P. Ged, and J. P. Noblanc, “Luminescence in highly conductive n-type ZnSe” , J. Appl. Phy. 46, 3549(1975)
[29] R. M. Park, M. B. Troffer, C. M. Rouleau, J. M. Depuydt and M. A. Hasse: Appl. Phys. Lett. 57 (1990) 2127
[30] J. Ren, K. A. Bowers, B. Sneed, D.L. Dreifus, J. W. Cook, Jr. J. F. Schetzina and R. M. Kolbas: Appl. Phys. Lett. 57 (1990) 1901
[31] K. Akimoto, T. Miyajima and Y. Mori: Phys. Rev. B 39 (1989) 3138
[32] G. Sun, K. Shahzad, J. M.Ganies and J. B. Khurgin. Appl. Phys. Lett. 59, 10(1991)
[33] B.Bollig, P.Thorhauer, E.Kubalek, J.Sollner, F.E.G.Guimaraes, M.Heuken and K.Heime, J. Cryst. Growth 124, 639(1992)
[34] K.Shazad, D.J.Olego and C.G Van de Walle, Phys.Rev.B38,1417 (1988)
[35] G. Sun, K. Shahzad, J. M. Gaines and J. B. Khurgin, "Room temperature photopumped blue lasing in ZnSe-ZnS0.06Se094 double heterostructures", Appl. Phys. Lett. 59, 310, 1991
[36] K. Ohkawa, T. Karasawa and T. Mitsuyu: Jpn. J. Appl. Phys. 30 (1991) L152
[37] K. Akimoto, T. Miyajima and Y. Mori, Jpn. J. Appl. Phys. 28 (1989) L531
[38] H. Okuyama, K. Nakano, T. Miyajimy and K. Akimoto, Jpn. J. Appl. 30 (1991) L1620
[39] T. Nakajama, Jpn, J. Appl. Phys. 33 (1994) L211
[40] J. Petruzello, J. Gaines and P. van der Sluis, J. Appl. Phys. 75 (1994) 63
[41] S. Itoh, N. Nakayama, T. Ohata, M. Ozawa, Hokuyama, K. Nakano, M. Ikeda, A. Ishibash and Y. Mori, J. Appl. Phys. 33, L639 (1994)
[42] M.Ukita,H.Okuyana,M.Ozawa,A.Ishibashi,K.Akimoto and Y.Mori, Appl.Phys.Lett.63 (1993) 2082
[43] H.Okuyama, K.Nakano, T.Miyajima and K.Akimoto, Jap. J. Appl. Phys. 30 (1991) L1620
[44] J. Petruzello, J. Gaines and P. van der Sluis, J. Appl. Phys. 75 (1994) 63
[45] J. M. Gaines, R. R. Drenten, K. W. Haberern, T. Marshall, and J. Petruzzello, "Blue-green injection lasers containing pseudomorphic ZnxMg1-xSySe1- y cladding layers and operating up to 394 K", Appl. Phys. Lett. 62(20), 2462, 1993
[46] A. Toda, T. Asano, K. Funato, F. Nakamura and Y. Mori. J. Cryst. Growth 145 (1994) 537
[47] H.M Manasevit and W.I Simposon, J.Electrochem.Soc.118 (1971) 644
[48] M. R. Lorenz, in: Physics and Chemistry of Ⅱ/Ⅵ compound, Eds. M. Aven and J. S. Prener (North-Holland, Amsterdan, 1976) ch2
[49] Study on ZnSe blue light emitting diode by OMVPE, M. Y. Yeh 1994
[50] Y. Kawakamin, B. C. Cavenett, K.Ichino, Sfujita. Jan. J. Appl. Phys. 32, L730 (1993)
[51] W. G. Oldham and A. G. Milnes, Solid State Electron. 7 153 (1964)
[52] J. R. Dale, Phys. Stat. Sol. 16,351 (1996)
[53] Study on ZnSe blue light emitting diode by OMVPE, M. Y. Yeh 1994
[54] W. G. Oldham and A. G. Milnes, Solid State Electron. 6, 121 (1963)
[55] D. B. Holt, J. Phys. Chem. Solids 27, 1053 (1996)
[56] R. G. Schulze, J. Appl. Phys. 37, 4295 (1996)
[57] L. W. Hong, N. F shin, T. S. Jen, S. L. Ning, and C. Y. Chang, IEEE Electron Device Lett., EDL-3, 375, 1992
[58] S. Froyenn, S. H. Wei and A. Zunger, Phys. Rev. B 38 (1988) 10 124
[59] Berthold Hahn, Marcus Deufel, Marcus Meier, Marcus J. Kastner, “Photoassisted growth and nitrogen doping of ZnSe”, Journal of Crystal Growth, 170(1997) 472-475
[60] J. Jeon, J Ding, A. V. Nurmikko, W. Xie, D. C Griio, M. Kobayashi, R. L.Gunshor, G. C. Hau and N. Otsuka. Appl. Phys. Lett. 60, 1999 (1992)
[61] K. Nakanishi, E. Suemune, Y. Fuji, Y. Kan and and M. Yamanishis. Appl. Phys. Lett. 59, 1401(1991)
[62] K. F. longenbach et al. “Modulated beam Epitaxial Growth of High Quality GaAs Single Quantum Wells at low temperature” Appl. Phys. Lett. Vol. 59 (7), 1991, p.820-822
[63] A. DOI et al “Growth of GaAs by Switched Layer Metalorganic Vapor Phase Epitaxy” Appl. Phys. Lett. P.1787-1789, 1986
[64] Y. Horikoski et al. Jpn. J. Phys. Vol. 25, L868, 1986.
[65] Y. Horikoski et al. “Photoluminescence Characteristics of AlgaAs/GaAs Single Quantum Well Grown by MEE at 300℃ Substrate temperature” Appl. Phys. Lett. Vol.50 p.1686-11687
[66] A. madhukar, Appl. Phys. Lett. Vol.46, p.1148-1150, 1985
[67] Nalki Kobayashi and Yoshiji horikoshi “Improved Flatness in GaAs/AlGaAs heterointerfaces Grown by Flow-Rate Modulation Epitaxy” Appl. Phys. Lett. Vol.50, p.909-911, 1986
[68] P. J. wang et al. “Vapor Phase Epitaxy of InP Using Flow Modulation”, Appl. Phys. Lett., vol.49, p.564-566, 1986
[69] D. K. Biegelsen et al. “ Initial Stages of Epitaxy Growth of GaAs on (100) Silicon” J. Appl. Phys. Lett. Vol.53, p.1509-1511, 1988
[70] M. J. Ludowise “Metalorganic chemical vapor deoposition of Ⅱ/Ⅵ semiconductor” J. Appl. Phys. Lett. 58, 31 (1985)
[71] Kunihiko UWAI “Effect of substrate temperature and Ⅴ/Ⅲ ratios on epitaxial InP grown by MOCVD” Jpn. J. Appl. Phys. 23, L121 (1984)
[72] K. Fujita, H. Kanao and Y. Shiba, “ Metal-organic chemical deposition growth of GaAs on Si using GaAs buffer layer grown by an alternate gas floe-of source materials”, Jpn. J. Appl. Phys. 30, 633 (1991)
[73] H. L. Hartnagel, A. L. Dawar, A. K. Jain and C. Jagadish, Semiconducting Transparent Thin Films (Institute of Physics, Bristol, 1995)
[74] H. Kim, A. Pique, J. S. Horwitz, H. Mattoussi, H. Murata, Z. H. Kafafi and D. B. Chrisey, Appl. Phys. Lett. 74, 3444 (1999)
[75] C. W. Tang and S. A. Van Slyke, Appl. Phys. Lett. 51, 913 (1987)
[76] T. Maruyama and K. Fukui, Thin Solid Films 203, 297 (1991)
[77] W. –F, Wu, B. –S, Chiou, and S. –T. Hsieh, Semicond. Sci. Technol. 9, 1242 (1994)
[78] M. Buchanan, J. B. Webb, and D. F. Williams, Appl. Phys. Lett. 37, 213 (1980)
[79] P. Nath, R. F. Bunshah, B. M. Basol and O. M. Staffsud, Thin Solid Films 72, 463 (1980)
[80] V. Vasu and A. Subrahmanyam, Thin Solid Films 193/194, 696 (1990)
[81] J. P. Zheng and H. S. Kwok, appl. Phys. Lett. 63, 1 (1993)
[82] C. Coutal, A. Azema and J. –C, Roustan, Thin Solid Films 288,248 (1996)
[83] F. Hanus, A Jadin and L. D. Laude, Appl. Surf. Sci. 96-98, 807 (1996)
[84] D. B. Chrisey and G. K. Hubler, Pulsed lase deposition of Thin Films (Wiley, New York, 1994)
[85] Epitaxial Growth of Nitrogen-Doped ZnSxSe1-x on GaAsyP1-y Substrates by OMVPE, 1997
[86] M. Piper and S. J. Polich, J. Appl. Phys. 32, 1278, 1961
[87] R. M. Park and H. A. Mar, Appl. Phys. Lett. 48, 529,1986
[88] S.G. Parker. J. Cryst. Growth 9, 177, 1971
[89] W. Stutius, “Oranometallic vapor deposition of rpitaxial ZnSe films on GaAs substrates”, Appl. Phys. Lett. 33(1978) 656
[90] Shizuo Fujita, Shigeo Fujita, “Photo-assisted metalorganic vapor phase epitaxial growth of wide-gap Ⅱ-Ⅵ semiconductors”, Journal of Crystal Growth, 117(1992) 67-74
[91] W. Stutius, J. Cryst. Growth 59, 1, 1982
[92] Blanconnier, M. Cerelet, P. Hence and A. M. Jean-Louis, 55, 375, 1978
[93] H. M. Manasevit and W. I. Simpson, J. Electroehem. Soc. 118, 6644, 1971
[94] Fan,J.C.C., Bachner,F.J.,”Properties of Sn-Doped In2O3 Films prepared by RF Sputtering”, J. Electrochem. Soc., 122:1719-1725, (1975)
[95] W. Helfrich and W.G. Schneider, Phys. Rev. Lett. 14, 229 (1965)
[96] C. W. Tang and S. A. Vanslyke, Appl. Phys. Lett. 51, 913 (1987)
[97] C. W. Tang, S. A. Vanslyke and C. H. Chen, J. Appl. Phys. 65, 3610 (1989)
[98] J. H. Burroughes, D. D. C. Bradley, A. R. Brown, R. N. Marks, K. MacKay, R. H. Friend, P. L. Burn and A. B. Holmes, Nature 347, 539 (1990)
[99] D. Braun and A. J. heeger, Appl. Phys. Lett, 58, 1982 (1991)
[100] G. Gustafsson, Y. Cao, G. M. Treacy, F. Klavetter and A. J. Heeger, Nature 357, 477 (1992)
[101] E. Gustafsson, P. Smith and A. J. heeger, Adv. Matter. 7, 788 (1995)
[102] G. Westerweele, P. Smith and A. J. Heeger, Adv. Mater. 7, 788 (1995)
[103] G. Yu, K. Pakbaz and A. J. Heeger, J. Electro. Mater. 23, 925 (1994)
[104] G. Yu, C. Zhang and A. J. Heeger, Appl. Phys. Lett. 64, 1540 (1994)
[105] A. J. Heeger and J. Long Jr., Optics & Photonic News, 23 (Aug., 1996)
[106] C. N. King, J. SID 4, 1(1996)
[107] T. Hirose, K. Kariya, M. Wakitani, A. Otsuka and T. Shinoda, SID Digest of Technical Papers, 279 (1996)
[108] F. Courreges, SID Digest of Technical Papers, 45 (1996)
[109] G. Gu, P. E. Burrows, S. Vankatesh and S. R. Forrest, Opt. Lett. 22, 172 (1997)
[110] 液晶之基礎與應用, p.226, 國立編譯館.
[111] H. Kim and C. M. Gilmore, J. App. Phy., pp6451, 11, 86 (1999).
[112] J. D. Hwang, Y. K. Fang, Y. J. Song, Thin Solid Films, pp8, 283, 8-11 (1996).
[113] B. P. Zhang, T. Yasuda, and Y. Segawa, Appl. Phys. Lett. 70, 2413 (1997)
[114] Hyun-Chu Ko, Doo-Cheol Park, Yoichi Kawakami, Shizuo Fujita, and Shigeo Fujita, Appl. Phys. Lett. 70, 3278 (1997)
[115] J A Venables, G D T Spiller and M Hanbucken, Rep. Prog. Phys. 47, 399 (1984)
[116] J. B. Smathers, E. Kneedler, B. R. Bennett, and B. T. Jonker, Appl. Phys. Lett. 72, 1239 (1998)
[117] X. B. Zhang and S. K. Hark, Appl. Phys. Lett. 74, 3857 (1999)