隨著電子元件日益微小化，具奈米尺度的結構及材料受到廣泛的重視，奈米材料的生長方式與其特性成了當前重要的課題，因此相關的研究也日新月異。鈷矽化物因為具有良好的電子特性，早在奈米線發展前，就常被利用在微電子元件上，做為歐姆接觸、內連線和閘極材料。本研究藉由熱蒸鍍方式，以氯化鈷為製備之前驅物，藉由控制爐管內矽和鈷元素的濃度，成功地合成出鈷矽化物奈米線。此實驗以鈷矽化物中之矽化鈷(CoSi)奈米線為主要研究材料，由結果得知，控制不同的反應溫度、壓力與時間，可以得到不同長寬比和密度的CoSi奈米線。此外，比較不同反應時間所生長之CoSi奈米線的形態，可推斷出本實驗中CoSi奈米線的生長為氣-固法(Vapor-Solid ,VS)的成長機制。
對CoSi奈米線而言，由於線直徑在奈米尺度下，有助其尖端放電，因此具有良好的場發性質，場發的增強因子和起始電壓大小則與奈米線的密度有很大的關連。在電性量測中，我們發現CoSi奈米線的電阻率會隨著直徑的增加而變大。除此之外，CoSi原為一反磁性材料，當合成為奈米線結構時，表面未成對的Co原子會誘發CoSi奈米線具有鐵磁性，在低溫下，由於較不受熱擾動影響，而具有較大的飽和磁化率。對不同直徑的CoSi奈米線來說，直徑越小的奈米線，磁化率越大且矯頑磁場越小，但總體而言，CoSi奈米線為一室溫鐵磁材料。

With the miniaturization of electron devices, the minuscule structures are important to state-of-the-art science and technology. Therefore, the growth methods and properties of nanomaterials have been extensively studied recently. Because of the excellent electronic properties, cobalt silicide has been used as the materials of ohmic contact, interconnect and gate of microelectronic devices. In this study, cobalt silicide nanowires were synthesized by chemical vapor transport process with cobalt chloride as the precursor under the appropriate concentration of silicon and cobalt. The fabrication process is economical as well as safe, and CoSi is the only thermodynamically stable phase that can be obtained on silicon wafer by solid phase reactions. By changing the reaction temperature and pressure, cobalt silicide nanowires with different size and density can be obtained. The CoSi nanowires were grown via a Vapor-Solid mechanism which can be inferred from different morphologies of CoSi nanowires with different reaction time, respectively.
The as-prepared CoSi nanowires, owing to their sharp tips, display good field emission property. The field enhancement factor and the threshold voltage are highly related to the density of nanowires. Moreover, the electronic properties were studied. The resistivity is proportional to the diameter of the CoSi nanowires.
The magnetic properties were also demonstrated in this work. The bulk CoSi is a diamagnetic semimetal. However, the CoSi nanowire ensemble exhibits magnetic property which induced by the reduced coordination of the surface Co atoms. At low temperature, the nanowires have relatively high saturated magnetization (Ms) due to less effect of thermal vibration. The CoSi nanowires with different diameters have diverse Ms and coercive force (Hc). In brief, the CoSi nanowires are room-temperature ferromagnetic materials.

摘要 Ⅰ
Abstrate Ⅲ
致謝 Ⅴ
目錄 Ⅵ
圖目錄 Ⅸ
表目錄 ⅩⅡ
List of Acronyms and Abbreviations ⅩⅢ
第一章　前言 1
第二章　文獻回顧 6
　　　2-1 奈米線的合成方法 6
　　　　　2-1-1 雷射消融法 6
　　　　　2-1-2 水熱法 7
　　　　　2-1-3碳還原法 7
　　　　　2-1-4 熱蒸鍍法 8
　　　2-2 矽化物奈米線的簡介 8
　　　　　2-2-1 金屬矽化物奈米線 8
　　　　　2-2-2 矽化鈷奈米線 10
第三章　實驗方法與步驟 17
　　　3-1 實驗步驟 17
　　　3-2 儀器分析 18
　　　　　3-2-1掃描式電子顯微鏡 18
　　　　　3-2-2 穿透式電子顯微鏡 18
　　　　　3-2-3 X-光繞射儀 19
　　　　　3-2-4 能量散失光譜儀 19
　　　　　3-2-5 場發量測 20
　　　　　3-2-6 電性量測 20
　　　　　3-2-7 磁性量測 20
第四章 結果與討論 25
　　　4-1 不同成長參數對矽化鈷奈米線型態的影響 25
　　　　　4-1-1 成長溫度 25
　　　　　4-1-2 成長壓力 27
　　　　　4-1-3 成長時間 29
　　　4-2 矽化鈷奈米線的生長機制 30
　　　4-3 場發特性 32
　　　4-4 電性量測 33
4-5 磁性量測 34
第五章 結論與未來展望 52
　　　5-1 結論 52
　　　5-2未來展望 53
參考文獻 54

[1] Wagner, R. S. and Ellis, W. C. "Vapor‐liquid‐solid mechanism of single crystal growth." Applied physics letters 1964, 4(5): 89-90.
[2] Schmitt, A. L.; Higgins, J. M.; Szczech, J. R. and Jin, S. "Synthesis and applications of metal silicide nanowires." Journal of Materials Chemistry 2010, 20(2): 223-235.
[3] Chen, L. J. "Metal silicides: An integral part of microelectronics." Jom 2005, 57(9): 24-30.
[4] Lin, Y. C.; Lu, K. C.; Wu, W. W.; Bai, J. W.; Chen, L. J.; Tu, K. N. and Huang, Y. "Single crystalline PtSi nanowires, PtSi/Si/PtSi nanowire heterostructures, and nanodevices." Nano Letters 2008, 8(3): 913-918.
[5] Weber, W. M.; Geelhaar, L.; Graham, A. P.; Unger, E.; Duesberg, G. S.; Liebau, M.; Pamler, W.; Cheze, C.; Riechert, H.; Lugli, P. and Kreupl, F. "Silicon-nanowire transistors with intruded nickel-silicide contacts." Nano Letters 2006, 6(12): 2660-2666.
[6] Ko, F. H.; Yeh, Z. H.; Chen, C. C. and Liu, T. F. "Self-aligned platinum-silicide nanowires for biomolecule sensing." Journal of Vacuum Science & Technology B 2005, 23(6): 3000-3005.
[7] Morales, A. M. and Lieber, C. M. "A laser ablation method for the synthesis of crystalline semiconductor nanowires." Science 1998, 279(5348): 208-211.
[8] Zhang, Y. F.; Tang, Y. H.; Wang, N.;Yu, D. P.; Lee, C. S.; Bello, I. and Lee, S. T. "Silicon nanowires prepared by laser ablation at high temperature." Applied physics letters 1998, 72(15): 1835-1837.
[9] Shi, W. S.; Zheng, Y. F.; Peng, H. Y.; Wang, N.; Lee, C. S. and Lee, S. T. "Laser ablation synthesis and optical characterization of silicon carbide nanowires." Journal of the American Ceramic Society 2000, 83(12): 3228-3230.
[10] Sun, Y.; Ndifor-Angwafor, N. G.; Riley, D. J. and Ashfold, M. N. R. "Synthesis and photoluminescence of ultra-thin ZnO nanowire/nanotube arrays formed by hydrothermal growth." Chemical Physics Letters 2006, 431(4-6): 352-357
[11] Zhao, J.; Jin, Z. G.; Liu, X. X. and Liu, Z. F. "Growth and morphology of ZnO nanorods prepared from Zn(NO3)2/NaOH solutions." Journal of the European Ceramic Society 2006, 26(16): 3745-3752.
[12] Wang, X. and Li, Y. D. "Selected-control hydrothermal synthesis of alpha- and beta-MnO2 single crystal nanowires." Journal of the American Chemical Society 2002, 124(12): 2880-2881.
[13] Zhang, Y. X.; Li, G. H.; Jin, Y. X.; Zhang, Y.; Zhang, J. and Zhang, L. D. "Hydrothermal synthesis and photoluminescence of TiO2 nanowires." Chemical Physics Letters 2002, 365(3-4): 300-304.
[14] Liu, Z. P.; Yang, Y.; Liang, J. B.; Hu, Z. K.; Li, S.; Peng, S. and Qian, Y. T. "Synthesis of copper nanowires via a complex-surfactant-assisted hydrothermal reduction process." Journal of Physical Chemistry B 2003, 107(46): 12658-12661.
[15] Wang, Z. H.; Liu, J. W.; Chen, X. Y.; Wan, J. X. and Qian, Y. T. "A simple hydrothermal route to large-scale synthesis of uniform silver nanowires." Chemistry-a European Journal 2005, 11(1): 160-163.
[16] Park, J. H.; Choi, Y. J. and Park, J. G. "Synthesis of ZnO nanowires and nanosheets by an O2-assisted carbothermal reduction process." Journal of Crystal Growth 2005, 280(1-2): 161-167.
[17] Wu, X. C.; Song, W. H.; Huang, W. D.; Pu, M. H.; Zhao, B.; Sun, Y. P. and Du, J. J. "Simultaneous growth of alpha-Si3N4 and beta-SiC nanorods." Materials Research Bulletin 2001, 36(5-6): 847-852.
[18] Zu Rong, D.; Zheng Wei, P. and Wang, Z. L. "Novel nanostructures of functional oxides synthesized by thermal evaporation." Advanced Functional Materials 2003, 13(1): 9-24.
[19] Seo, K.; Varadwaj, K. S. K.; Mohanty, P.; Lee, S.; Jo, Y.; Jung, M. H.; Kim, J. and Kim, B. "Magnetic properties of single-crystalline CoSi nanowires." Nano Letters 2007, 7(5): 1240-1245.
[20] Lian, O. Y.; Thrall, E. S.; Deshmukh, M. M. and Park, H. "Vapor-phase synthesis and characterization of epsilon-FeSi nanowires." Advanced Materials 2006, 18(11): 1437-1440.
[21] Ham, M. H.; Lee, J. W.; Moon, K. J.; Choi, J. H. and Myoung, J. M. "Single-Crystalline Ferromagnetic Mn4Si7 Nanowires." Journal of Physical Chemistry C 2009, 113(19): 8143-8146.
[22] Murarka, S. P. "Refractory silicides for integrated-circuits." Journal of Vacuum Science & Technology 1980, 17(4): 775-792.
[23] Gambino, J. P. and Colgan, E. G. "Silicides and ohmic contacts." Materials Chemistry and Physics 1998, 52(2): 99-146.
[24] Xiang, B.; Wang, Q. X.; Wang, Z.; Zhang, X. Z.; Liu, L. Q.; Xu, J. and Yu, D. P. "Synthesis and field emission properties of TiSi2 nanowires." Applied physics letters 2005, 86(24):243103-1-3.
[25] Lin, H. K.; Tzeng, Y. F.; Wang, C. H.; Tai, N. H.; Lin, I. N.; Lee, C. Y. and Chiu, H. T. "Ti5Si3 nanowire and its field emission property." Chemistry of Materials 2008, 20(7): 2429-2431.
[26] Chueh, Y. L.; Ko, M. T.; Chou, L. J.; Chen, L. J.; Wu, C. S. and Chen, C. D. "TaSi2 nanowires: A potential field emitter and interconnect." Nano Letters 2006, 6(8): 1637-1644.
[27] Lee, C. Y.; Lu, M. P.; Liao, K. F.; Lee, W. F.; Huang, C. T.; Chen, S. Y. and Chen, L. J. "Free-standing single-crystal NiSi2 nanowires with excellent electrical transport and field emission properties." Journal of Physical Chemistry C 2009, 113(6): 2286-2289.
[28] Lee, C. Y.; Lu, M. P.; Liao, K. F.; Wu, W. W. and Chen, L. J. "Vertically well-aligned epitaxial Ni31Si12 nanowire arrays with excellent field emission properties." Applied physics letters 2008, 93(11): 113109-1-3.
[29] Song, Y. P.; Schmitt, A. L. and Jin, S. "Ultralong single-crystal metallic Ni2Si nanowires with low resistivity." Nano Letters 2007, 7(4): 965-969.
[30] Kang, K.; Kim, S. K.; Kim, C. J. and Jo, M. H. "The role of NiOx overlayers on spontaneous growth of NiSix nanowires from Ni seed layers." Nano Letters 2008, 8(2): 431-436.
[31] Lu, K. C.; Wu, W. W.; Wu, H. W.; Tanner, C. M.; Chang, J. P.; Chen, L. J. and Tu, K. N. "In situ control of atomic-scale Si layer with huge strain in the nanoheterostructure NiSi/Si/NiSi through point contact reaction." Nano Letters 2007, 7(8): 2389-2394.
[32] Schmitt, A. L.; Bierman, M. J.; Schmeisser, D.; Himpsel, F. J. and Jin, S. "Synthesis and properties of single-crystal FeSi nanowires." Nano Letters 2006, 6(8): 1617-1621.
[33] Schmitt, A. L.; Higgins, J. M. and Jin, S. "Chemical synthesis and magnetotransport of magnetic semiconducting Fe1-xCoxSi alloy nanowires." Nano Letters 2008, 8(3): 810-815.
[34] Zhang, S. L. and Ostling, M. "Metal silicides in CMOS technology: Past, present, and future trends." Critical Reviews in Solid State and Materials Sciences 2003, 28(1): 1-129.
[35] Appelbaum, A.; Knoell, R. V. and Murarka, S. P. "Study of cobalt-disilicide formation from cobalt monosilicide." Journal of Applied Physics 1985, 57(6): 1880-1886.
[36] Iwai, H.; Ohguro, T. and Ohmi, S. "NiSi salicide technology for scaled CMOS." Microelectronic Engineering 2002, 60(1-2): 157-169.
[37] Kamal, A. H. M.; Obeidat, A. T. and Budri, T. "Suppressing baron penetration and cobalt silicide agglomeration in deep submicron p-channel metal-oxide-semiconductor devices." Journal of Vacuum Science & Technology B 2002, 20(1): 173-179.
[38] Schmitt, A. L.; Zhu, L.; Schmeisser, D.; Himpsel, F. J. and Jin, S. "Metallic single-crystal CoSi nanowires via chemical vapor deposition of single-source precursor." Journal of Physical Chemistry B 2006, 110(37): 18142-18146.
[39] Seo, K.; Lee, S.; Yoon, H.; In, J.; Varadwaj, K. S. K.;Jo, Y.; Jung, M. H.; Kim, J. and Kim, B. "Composition-tuned ConSi nanowires: location-selective simultaneous growth along temperature gradient." Acs Nano 2009, 3(5): 1145-1150.
[40] Tsai, C. I.; Yeh, P. H.; Wang, C. Y.; Wu, H. W.; Chen, U. S.; Lu, M. Y.; Wu, W. W.; Chen, L. J. and Wang, Z. L. "Cobalt silicide nanostructures: synthesis, electron transport, and field emission properties." Crystal Growth & Design 2009, 9(10): 4514-4518.
[41] H. J. Williams; J. H. Wernick; R. C. Sherwood and Wertheim, G. K. "Magnetic properties of the monosilicides of some 3d transition elements." Journal of Applied Physics 1966, 37(3): 1256.
[42] 汪建民 “材料分析”中國材料科學學會
[43] 許樹恩、吳泰伯 “X光繞射原理與材料結構分析”中國材料科學學會
[44] http://fmpanlab.twbbs.org
[45] 楊鴻昌”超導量子干涉磁量儀”科儀新知 第 62 期 (第 12 卷第 6 期)，72–79 頁，1991
[46] Kim, C. J.; Kang, K.; Woo, Y. S.; Ryu, K. G.; Moon, H.; Kim, J. M.; Zang, D. S. and Jo, M. H. "Spontaneous chemical vapor growth of NiSi nanowires and their metallic properties." Advanced Materials 2007, 19(21): 3637-3642.
[47] Joyce, H. J.; Gao, Q.; Tan, H. H.; Jagadish, C.; Kim, Y.; Zhang, X.; Guo, Y. N. and Zou, J. "Twin-free uniform epitaxial GaAs nanowires grown by a two-temperature process." Nano Letters 2007, 7(4): 921-926.
[48] Seo, K.;Varadwaj, K. S. K.;Cha, D.;In, J.;Kim, J.;Park, J. and Kim, B. "Synthesis and electrical properties of single crystalline CrSi2 nanowires." Journal of Physical Chemistry C 2007, 111(26): 9072-9076.
[49] Okino, H.; Matsuda, I.; Hobara, R.; Hosomura, Y.; Hasegawa, S. and Bennett, P. A. "In situ resistance measurements of epitaxial cobalt silicide nanowires on Si(110)." Applied physics letters 2005, 86(23): 233108-1-3.
[50] Lin, Y. F. and Jian, W. B. "The Impact of nanocontact on nanowire based nanoelectronics." Nano Letters 2008, 8(10): 3146-3150.
[51] Takayanagi, K.; Kondo, Y. and Ohnishi, H. "Suspended Gold Nanowires Ballistic Transport of Electrons." JSAP International 2001, 3, 3-8.
[52] Lim, D. K.; Kubo, O.; Shingaya, Y.; Nakayama, T.; Kim, Y. H.; Lee, J. Y.; Aono, M.; Lee, H.; Lee, D. and Kim, S. "Low resistivity of Pt silicide nanowires measured using double-scanning-probe tunneling microscope." Applied physics letters 2008, 92(20): 203114-1-3.
[53] Nielsch, K.; Wehrspohn, R. B.; Barthel, J.; Kirschner, J.; Gosele, U.; Fischer, S. F. and Kronmuller, H. "Hexagonally ordered 100 nm period nickel nanowire arrays." Applied physics letters 2001, 79(9): 1360-1362.