在此研究中，建立一套熱力學模型模擬MBE成長GaAs/Si之缺陷結構並針對GaAs / Si的製程進行討論，包括成長初始層、熱處理、一般成長、N-type摻雜及高溫退火處理，接著計算發生在此平衡系統中的缺陷濃度，模擬結果顯示缺陷濃度是由成長溫度、V/III比及氣體分壓等參數所決定。
對於GaAs/Si磊晶製程部分，先以低溫成長緩衝層其成長速率慢但磊晶層品質較好，而模擬結果顯示當成長溫度低於450℃時，缺陷濃度下降緩慢，因此，成長溫度在450℃以上為佳。至於更低溫的類磊層(~300℃)，雖無法由模擬予以討論，但隨之的熱退火處理步驟將使之再結晶，其中缺陷結構也將重新排列。模擬進行隨PAs2變化時之缺陷結構，考慮AsGa為深能階的缺陷，我們期望Ga-rich GaAs 能被成長且AsGa在GaAs中並非主導。在成長完緩衝層之後，由熱力學模擬決定之GaAs磊晶層成長溫度，其範圍約在450℃~630℃，由熱力學分析所決定出的成長條件範圍十分重要且其結果均可在參考文獻得到驗證。
Si摻雜之GaAs在熱退火處理中是在充滿PAs4的分壓下進行的，假使摻雜Si:1×1018cm-3控制在溫度及PAs4分別為1000℃及10-3~101atm時，在此條件下，可得到N-type GaAs中的SiGa及SiAs成為主導。
對於GaAs磊晶層之電性模擬部分，在常溫時自由載子濃度、離子摻雜及中性摻雜散射與缺陷結構有關。MBE成長之GaAs 磊晶層的自然摻雜多為P-type，且其濃度及遷移率約1015cm-3及300(cm2/V-sec)，此熱力學分析及計算結果與眾多參考文獻一致。
理所當然，以任何理論分析預測預測品質經常缺乏相關資料。然而，熱力學計算與電性分析有助於識別出最少的實驗量用以決定出最有用的資料。

In this study, a thermodynamic model was built to apply to discuss the defect structure of GaAs epitaxial film grown on Si substrate by MBE, and it was specially focus on the GaAs/Si growth process. . It includes the initial layer, thermal treatment, epitaxial growth, n-type doping and the high temperature thermal annealing. The defect concentrations were calculated in thermal equilibrium. The result of simulation shows that defect concentration is dependent on the growth parameters such as the substrate temperature, V/III ratio and the input reactant pressure.
For the GaAs/Si epitaxial process, the buffer layer was grown at low temperature with a slow growth rate but better the film. On the result of simulations, it shows that the defect concentrations decrease very slowly as the growth temperature below 450℃. So the substrate temperature selected for the initial film growth could be above 450oC. The defect structure of epitaxial layer grown pseudo-morphically at low temperature(~300℃) was beyond our calculation. The re-crystallization of epitaxial layer and the redistribution of defects were occurred during the thermal annealing process. The defect structure of GaAs epilayer were simulated as a function of arsenics pressure in the annealing process. It is expected that the Ga-rich GaAs epilayer is obtained, and the AsGa is not the dominant defect in the epilayer since AsGa is a deep energy level defect. After the buffer layer was grown, the growth temperature of GaAs epilayer could be simulated by thermodynamic analysis, and the results were obtained at 450℃~630℃. It is important to determine the growth windows of GaAs epilayer by the thermodynamic analysis, and the results of simulation were verified by several reports.
The Si-doped GaAs layers are processed by thermal annealed under an arsenic overpressure. For the Si-doped level estimated to be 1018cm-3, the annealing temperature and As4 overpressure used in simulation were at 1000℃ and 10-3 ~ 10 atm, respectively. An n-type GaAs epilayer with dominant defects SiGa and SiAs were obtained under the annealing condition.
For electrical characterization of GaAs epilayer, it was found that free carrier concentration, ion-scattering mobility and neutral-scattering mobility at room temperature were relate to the defect structure of GaAs epilayer, and the nature doping of GaAs epilayer grown by MBE is usually p-type. The free carrier concentration and total mobility of GaAs epilayer are about 1015cm-3 and 300 cm2/sec-V, respectively. The result of thermodynamic analysis and calculation are very close to the data reported.
Typically, it is of course, as being with any theoretical analysis, often a shortage of relevant data in which to quantify the predictions. However, the calculation of thermodynamic framework and the analysis of electrical characterization could help to decrease the minimum number of experiments needed to get the most useful data.

目錄
附表目錄………………………………………..…………..I
附圖目錄……………………………………….………….II
第一章 導 論…………………………….…………1
1-1 GaAs on Si的優點………………………………..…….…...1
1-2製程技術…………………………………………………….2
1-3 熱力學應用在缺陷結構上的模擬…………..……………..2
1-4 電性模擬…………………………………………..………..3
1-5 熱力學重要理論………………………………..…………..4
1-6 摘要…………………………………………..……………..6
第 二 章 GaAs/Si製程技術………………….…………7
2-1 成長GaAs/Si的問題………………………………..….…..7
2-2 Dislocation(差排)………………………………………..…..7
2-3斜向基板………………………..…….….………………….8
2-4表面製備技術……………………………...…..………...…10
2-5 預積層與兩階段成長………………………..……………10
2-6 成長超晶格 (SLSs)……………………………..……...…11
2-7 Si 離子束的注入及退火處理………………………..……12
2-7-1 Si Ions Implant (離子佈植)…………………...…………………12
2-7-2 Thermal Annealing (熱退火)…………………………………....12
2-8 MBE成長流程………………………………………..……13
第三章 缺陷模型………………………………….……..15
3-1缺陷的Enthalpy 及 Entropy…………………………..….15
3-1-1 Antistructure Defect (反位)………………………..……………15
3-1-2 Single Vacancy Formation (空位)…………………………..…..16
3-1-3 GaP成長之晶格能………………………………….…….…….17
3-2 LPE的成長機制……………………………………..…….18
3-2-1 Ga及As在GaAs中的生成能…………………………….…..18
3-2-2 反應方程式……………………………………………...………19
3-2-3 求解點缺陷的步驟…………………………………...…………21
3-3 MBE的成長機制…………………..………………………23
3-3-1反應平衡氣體分壓…………………..…….…………….……....23
3-3-2氣體與晶格內部缺陷關係……………..….…………….………23
3-3-3反應方程式及平衡方程式…………………...………………….24
3-4 MOCVD的成長機制…………………….……………..…26
3-4-1反應平衡氣體分壓………………………………..….………….26
3-4-2反應方程式及平衡方程式…………………………..……….…27
3-5 Si Ions Implant……………………………...………..…….28
3-5-1離子佈植及RTP之氣體反應……………….…..…………..….28
3-4-2 Si的摻雜特性……………………………………..……………28
3-5-3 反應方程式及平衡方程式……………………………...….……29
3-5-4 AsGa解離之考量…………………………………………………30
3-6電子解離率……………………………………...………….32
3-6-1缺陷能階………………………………………………...……….32
3-6-2多摻雜能階………………...…………………………………….32
3-7 Mobility(遷移率)…………….…………….………………35
第 四 章 結果與討論………….……………………..38
4-1 LPE成長趨勢………………………..…….………………38
4-2 MBE成長模型………………………….…………………38
4-2-1 Initial Layer……………………………..……………..39
4-2-2 Annealing Treatment…………………….……….……39
4-2-3 第二階段成長條件與討論………………….….….…40
4-3 Si離子佈植討論……………………………………..…….42
4-4 MOCVD與MBE 缺陷結構之比較…………….…...……43
4-5 缺陷對電性之影響…………………………………..…....44
參考文獻………………………………………...………..46

[01] A. S. Jordan, A. R. Von Neida, R.Caruso, C. K. Kim , Determination of the Solidus and Gallium and Phosphorus Vacancy Concentrations in GaP ,J. Electrochem. Soc. : Solid-State Science And Technology 1 (1974) 153
[02] J. A. Van Vechten , Simple Theoretical Estimates of the Enthalpy of Antistructure Pair Formation and Virtual-Enthalpies of Isolated Antisite Defects in Zinc-Blende and Wurtzite Type Semiconductors , J. Electrochem. Soc. : Solid-State Science And Technology 3 (1975) 423
[03] J. A. Van Vechten , Simple Theoretical Estimates of the Schottky Constants and Virtual-Enthalpies of Single Vacancy Formation in Zinc-Blende and Wurtzite Type Semiconductors , J. Electrochem. Soc.: Solid-State Science And Technology 3 (1975) 419
[04] G. M. Blom , Native Defects and Stoichiometry in GaAlAs , Journal of Crystal Growth 36 (1976) 125-137
[05] Masaya and Takao Wada , Native Defects in III-V Ternary Alloy Semiconduxtors Grown from Liquid-Solutions , Japanese Journal of Applied Physics 29 (1990) 1515
[06] M. Ichimura , K. Higuchi ,Y. Hattori , and T. Wada , Native defects in the AlxGa1-xSb alloy semiconduxtor , Journal of Applied Physics 68 (1990) 6153
[07] T.Y. Tan , Point defect thermal equilibria in GaAs , Materials Science and Engineering B10 (1991)227
[08] T.Y. Tan, H.-M. You, U.M. Gösele , Thermal Equilibrium Concentrations and Effects of Negetively Charged Ga Vacancies in n-Type GaAs , Applied Physics A 56 (1993) 249
[09] T.Y. Tan , U. Gösele, and S.Yu , Point Defects, Diffusion Mechanisms , and Superlattice Disordering in Gallium arsenide-Based Materials , Critical Reviews in Solid State and Materials Science. 17(1991) 47
[10] Masaya Ichimura and Takao Wakao Wada , Calculation of point defect concentrations in GaAs grown by molecular beam epitaxy , Journal Applied Physics 72 (1992) 1200
[11] D. T. J. Hurle , Solubility and Point Defect-Dopant Interactions in GaAs－III , J. Phys. Chem. Solids 40 (1979) 647
[12] D. T. J. Hurle , Solubility and Point Defect-Dopant Interactions in GaAs－II , J. Phys. Chem. Solids 40 (1979) 627
[13] D. T. J. Hurle , Solubility and Point Defect-Dopant Interactions in GaAs－I ,J. Phys. Chem. Solids 40 (1979) 639
[14] S.F. Fang, K. Adomi, S. lyer, H. Morkoc, and H. Zabel, Gallium arsenide and other compound semiconductors on silicon , J. Appl. Phys. 68(1990)R31
[15] R. Fischer and H. Morkoc, Material properties of high-quality GaAs epitaxial layers grown on Si substrates , J. Appl. Phys. 60(1986)1640
[16] C. Choi and N. Otsuka, Effect of in situ and ex situ annealing on dislocations in GaAs on Si substrates , Appl. Phys. Lett. 50(1987)992
[17] Masahiro Akiyama, Yoshihiro Kawarada and Katsuzo Kaminishi, Growth of Single Domain GaAs Layer on (100)-Oriented Si Substrate by MOCVD , Japanese Journal of Applied Physics 23 (1984) L843-L845
[18] J.W. Lee, H. Shichijo, H.L. Tsai, and R.J. Matyi, Defect reduction by thermal annealing of GaAs layers grown by moclecular beam epitaxy on Si substrates , Applied Physical Letter 50(1987)31
[19] Masafumi Yamaguchi, Akio Yamamoto, Masami Tachikawa, Yoshi Itoh, and Mitsuru Sugo, Defect reduction effects in GaAs on Si substrates by thermal annealing , Applied Physical Letter 53(1988)2293
[20] Takashi Egawa, Yoshiaki Hasegawa, Takashi Jimbo, and Masayoshi Umeno, Effects of Dislocation and Stress on Characteristics of GaAs-Based Laser Grown on Si by Metalorganic Chemical Vapor Deposition , Jpn. J. Appl. Phy. 31(1992) 791-797
[21] Mohamed TMAR, Armand GABRIE, Christian CHATILLON and Ibrahim ANSARA, Critical Analysis and Optimization of the Thermodynamic Properties and Phase Diagrams of the III-V Compounds , J. of Crystal Growth, 69(1984) P. 421-441
[22] D. W. SHAW , A Comparative Thermodynamic Analysis of InP and GaAs Deposition , J. Phys. Chem. Solids, 36(1975) P. 111-118
[23] S.V. Ivanov , P.S. Kop’ev and N.N. Ledentsov, Thermodynamic anlysis of segregation effects in MBE of AIII-BV compounds , J. of Crystal Growth, 111(1991) P. 151
[24] Chatillon, C.; Chatain, D., Congruent vaporization of GaAs(s) and stability of Ga(1) droplets at the GaAs(s) surface , J. of Crystal Growth, 151(1995) P. 91
[25] S. V. Ivanov, P. D. Altukhov, T. S. Argunova, A. A. Bakun, A. A. Budza , Molecular Beam Epitaxy Growth and Characterization of Thin (<2um) GaSb Layers on GaAs(100) Substrates , Semicond. Sci. Technol. 8 (1993) P. 347-356
[26] S. V. Ivanov, P. S. KOP’EV and N. N. Ledentsov, Thermodynamic Analysis of Segregation Effects in Molecular Beam Epitaxy , J. of Crystal Growth, 104 (1990) P.345-354
[27] D.H. Zhang, K. Radhakrishnan, S. F. Yoon, and H. M. Li, Be-doped GaAs layers grown at a high As/Ga ratio by molecular beam epitaxy , J. Vac. Sci. Technol. A 12(1994)1120
[28] Robert Chow, Rouel Femandez, and David Atchley, Characterization of high purity GaAs films grown by molecular-beam epitaxy from a solid As cracker , J. Vac. Sci. Technol. B 8(1990)163
[29] B. J. Skromme, S. S. Bose, B. Lee, T. S. Low, T. R. Lepkowski, R. Y. DeJule, and G. E. Stillman, Characterization of high-purity Si-doped molecular beam epitaxial GaAs , J. Appl. Phys. 58(1985)4686
[30] Naresh Chand, R.C. Miller, A. M. Sergent, S. K. Sputz, and D. V. Lang, Effect of arsenic source on the growth of high-purity GaAs by molecular beam epitaxy , Appl. Phys. Lett. 52(1988)1721
[31] K. Tappura, A. Salokatve, K. Rakennus, H. Asonen, and M. Pessa, Comparative study of the substrate-film interfaces of GaAs grown by two molecular beam epitaxial methods , Appl. Phys. Lett. 57(1990)2313
[32] L.T.P. Allen and E.R. Weber , Device quality growth and characterization of (110) GaAs grown by molecular beam epitaxy , Appl. Phys. Lett. 51(1987)670
[33] Ai-zhen Li, A. G.Milnes, Z. Y. Chen, Y. F. Shao, and S. B. Wang, Germanium incorporation in heavily doped molecular beam epitaxy grown GaAs:Ge , J. Vac. Sci. Technol. B 3(1985)629
[34] Jack P. Salemo, E. S. Koteles, J. V. Gormley, B. J. Sowell, E. M. Brody, J. Y. Chi, and R. P. Holmstrom, Effect of As/Ga flux ratio on the photoluminescence spectra of low donor concentration MBE GaAs , J. Vac. Sci. Technol. B 3(1985)618
[35] Yi-Ching, Effect of hydrogen on undoped and lightly Si-doped molecular beam epitaxial GaAs layers , Appl. Phys. Lett. 48(1986)1291
[36] R.N. Sacks and R.A. Pastoreilc, Effects of hot sources on residual doping in GaAs grown by molecular beam epitaxy , Appl. Phys. Lett. 52(1988)996
[37] Masanori Shinohara, Fumiaki Hyuga, Kazuo Watanabe, and Yoshihiro Imamura, Dislocation effects on carrier concentration for molecular-beam-epitaxially grown GaAs , J. Appl. Phys. 60(1986)304
[38] Loren Pfeiffer, K. W. West, H. L. Stormer, J. P. Eisenstein, K. W. Baldwin, D. Gershoni, and J. Spector, Formation of a high quality two-dimensional electron gas on cleaved GaAs , Appl. Phys. Lett. 56(1990)1697
[39] Naresh Chand, F. Ren, A.T. Macrander, J. P. van der Ziel, A. M. Sergent, R. Hull, S. N. G. Chu, Y. K. Chen, and D. V. Lang , GaAs-on-Si: Improved growth conditions, properties of undoped GaAs, high mobility, and fabrication of high-performance AlGaAs/GaAs selectively doped heterostructure transistors and ring oscillators ,
J. Appl. Phys. 67(1990)2343
[40] C.H. Goo, W. S. Lau, T. C. Chong, and L. S. Tan , High oxygen and carbon contents in GaAs epilayers grown below a critical substrate temperature by molecular beam epitaxy , Appl. Phys. Lett. 68(1996)841
[41] Bijan Tadayon, Saied Tadayon, M. G. Spencer, G.L. Harris, J. Griffin, and L.F. Eastman, Increase of electrical activation and mobility of Si-doped GaAs, grown at low substrate temperatures, by the migration-enhanced epitaxy method ,
J. Appl. Phys. 67(1990)589
[42] T. J. de Lyon, J.M. Woodall, J. A. Kash, D. T. Mclnturff, R. J. S. Bates, P. D. Kirchner, and F. Cardone, Minority carrier lifetime and photoluminescent response of heavily carbon-doped GaAs grown with gas source molecular-beam epitaxy using halomethane doping source , J. Appl. Phys. 57(1985)1922
[43] D.L. Miller, R. T. Chen, K. Elliott, and S. P. Kowalczyk, Molecular-beam-epitaxy GaAs regrowth with clean interfaces by arsenic passivation , J. Appl. Phys. 49(1986)391
[44] J.C. Bourgoin , H.J. von Bardeleben and D.Stievenard , Native defects in gallium arsenide , J. A. P. 64 (1988) R65
[45] P. J. Lin-Chung and T. L. Reinecke , Theoretical study of native defects in III-V semiconductors , Physical Review B 27(1983) 1101
[46] S. Loualiche , A. Nouailhat ,and M. Lannoo , Theoretical Discussion of Deep Level Optical And Thermal Spectroscopy In Semiconductors : Application To E1 And E2 In GaAs , Solid State Communications 51(1984) 509-513
[47] Anouar Jorio, Lamia Sellami, Marcel Aubin, and Cosmo Carlone , Effect of intrinsic defects on the electron mobility of gallium arsenide grown by molecular beam epitaxy and metal organic chemical vapor deposition , J. A. P. 91(2002) 9887
[48] Andrew E. Youtz and Bahram Nabet , Role of intermediate temperature molecular beam epitaxy grown GaAs defects in tunneling and diffusion , J. A. P. 84(1998)2697
[49] J. D. Wiley and M. DiDomenico , Lattice Mobility of Holes in III-V compounds , Physical Review B 2 (1970) 427
[50] G. E. Stillman and C. M. Wolfe, Electrical Characterization of Epitaxial Layers , Thin Solid Films, 31 (1976) 69-88
[51] D.T.J. Hurle, Revised Calculation of Point Defect Equilibria and Non-stoichiometry in Gallium Arsenide , J. Phys. Chem. Solids 40 (1979) 613