西元1957 年, 諾貝爾物理獎頒給電晶體發明者, Shockley、Bardeen 和Brattain, 同時也
宣告電晶體時代的來臨, 比起真空管, 電晶體擁有許多優點, 如: 體積小、損耗功率低等。
次微米級電晶體至今已經風光了半個世紀, 目前許多科學家正積極的研發體積更小, 靈敏
度更高的奈米級電晶體。其中利用奈米碳管作為源極和汲極間的通道的奈米碳管電晶體,
已經有一個初步的結果[1]。一般的電晶體都是利用閘極來控制電子是否通過源極和汲極
間的通道, 在此和以往不同, 我們將利用電子自旋的特性來製成自旋電子元件, 由電子自
旋方向來決定, 電子是否通過碳管所製成的通道。
在第一章中, 我們將簡介奈米碳管, 包括生成方式、晶格結構、電子能帶結構、電性,
在此有許多資料提供了對奈米碳管更詳盡的描述[2, 3]。
第二章將論述在奈米碳管中電子自旋傳輸現象。以往利用鐵磁性物質將自旋電子注入
至半導體中[4], 最大的困難就是鐵磁性物質和半導體間的導值不批配問題, 我們將利用單
自旋金屬(half-metal), Chromium dioxide (CrO2), 來解決這個問題, CrO2 是一新穎
的單自旋金屬材料[5, 6], 其擁有接近100% 的電子自旋極化率。另一個問題, 自旋電子
在一般散射性傳輸的物質中易受到散射, 因此, 我們利用金屬性奈米碳管的彈道傳輸特性
(ballistic transport) 作為一個極佳的自旋電子傳輸通道。
在第三章中, 我們敘述自旋元件的製程方法, 首先利用化學氣相沈積法成長CrO2 薄
膜, 用拋光技術將薄膜表面平坦化, 之後在薄膜之上利用光學微影製程製作出外圍電極和
定位碳管位置的記號; 在奈米碳管方面, 利用超音波震盪的方式, 將雷射法生成且糾纏在
一起的奈米碳管分散且懸浮於溶液中, 再將奈米碳管沈積到薄膜上面, 最後在原子力顯微
鏡的幫助下, 尋找且選定特定的碳管, 然後使用電子束微影技術和蝕刻技術製作出單自旋
金屬電極, 即完成元件的製作。
第四章將論述我們實驗室自己成長的單自旋金屬- CrO2, 在電子顯微鏡下和X-ray繞射、磁性、電性傳輸特性上的分析結果。

[1] S. J. Tans and A. R. M. Verschueren, “Room-temperature transistor based on a single carbon nanotube,” Nature, vol. 393, p. 49, 1998.
[2] T. Ando, H. Matsumura, and T. Nakanishi, “Theory of ballistic transport in carbon nanotubes,” Physica B, vol. 323, p. 44, 2002.
[3] P. L. McEuen, “Single-wall carbon nanotubes,” Phys. World, vol. 13, p. 31, 2000.
[4] R. Fiederling, M. Keim, and G. Reuscher, “Injection and detection of a spinpolarized current in a light-emitting diode,” Nature, vol. 402, p. 787, 1999.
[5] A. Anguelouch, A. Gupta, and G. Xiao, “Near-complete spin polarization in atomically-smooth chromium-dioxide epitaxial films prepared using a CVD liquid
precursor,” Phys. Rev. B, vol. 64, p. 180408, 2001.
[6] M. Rabe, J. Pommer, and K. Samm, “Growth and magnetotransport study of thin ferromagnetic CrO2 films,” J. Phys.: Condens. Matter, vol. 14, p. 7, 2002.
[7] “http://ac16.uni-paderborn.de/lehrveranstaltungen
/_aac/vorles/skript/kap_4/kap4_1/vsepr.html.”
[8] “http://userpage.chemie.fu-berlin.de/~abram/e_learning/html/org_grund/a_3b.htm.”
[9] “http://www.grenvillescience.com
/chemistry/y6l/asdef.html.”
[10] H. W. Kroto, J. R. Heath, and S. C. O’Brien, “C60: Buckminsterfullerene,”Nature, vol. 318, p. 162, 1985.
[11] S. Iijima, “Helical microtubules of graphite carbon,” Nature, vol. 354, p. 56, 1991.
[12] S. I. nad Toshinari Ichihashi, “Single-shell carbon nanotubes of 1-nm diameter,”Nature, vol. 363, p. 603, 1993.
[13] P. N. Andreas Thess, Roland Lee, “Crystalline ropes of metallic carbon nanotubes,”Science, vol. 273, p. 483, 1996.
[14] H. M. Cheng, F. Li, and G. Su, “Large-scale and low-cost synthesis of singlewalled carbon nanotubes by the catalytic pyrolysis of hydrocarbons,” App.Phys.
Lett., vol. 72, p. 3282, 1998.
[15] J. Kong, H. T. Soh, and A. M. Cassell, “Synthesis of individual singlewalled carbon nanotubes on patterned siliconwafers,” Nature, vol. 395, p. 878, 1998.
[16] R. Seidel, “Carbon nanotube devices,” Ph.D. dissertation, Fakultat Maschinenwesen
der Technischen Universitat Dresden, 2004.
[17] B. G. Streetman and S. Banerjee, Solid state electronic devices.
[18] R. Satio, G. Dersselhaus, and M. S. Dresselhaus, Physical properties of carbon
nanotubes. Imperial College Press, 1998.
[19] R. Saito, M. Fujita, and G. Dresselhaus, “Electronic structure of graphene
tubules based on C60,” Phsy. Rev. B, vol. 46, p. 1804, 1992.
[20] C. L. Kane and E. J. Mele, “Size, shape, and low energy electronic structure of carbon nanotubes,”
Phys. Rev. Lett., vol. 78, p. 1932, 1997.
[21] M. Ouyang and J.-L. Huang, “Energy gaps in ”metallic” single-walled carbon
nanotubes,” Science, vol. 292, p. 702, 2001.
[22] A. Ugawa, A. G. Rinzler, and D. B. Tanner, “Far-infrared gaps in single-wall carbon nanotubes,”
Phys. Rev. B, vol. 60, p. R11305, 1999.
[23] M. E. Itkis, “Spectroscopic study of the fermi level electronic structure of singlewalled carbon nanotubes,”
Nano Lett., vol. 2, p. 155, 2002.
[24] M. N. Baibich, J. M. Broto, and A. Fert, “Giant magnetoresistance of (001)Fe/(001)Cr magnetic superlattices,” Phys. Rev. Lett., vol. 61, p. 2472, 1988.
[25] J. S. Moodera, L. R. Kinder, and T. M. Wong, “Large magnetoresistance at room temperature in ferromagnetic
thin film tunnel junctions,” Phys. Rev.
Lett., vol. 74, p. 3273, 1995.
[26] I. J. GUILARAN, “Spin-dependent transport in ferromagnet-based devices,”
Ph.D. dissertation, FLORIDA STATE UNIVERSITY, 2004.
[27] M. Julliere, “Tunneling between ferromagnetic films,” Phys. Lett. A, vol. 54, p.225, 1975.
[28] A. Fert and H. Jaffres, “Conditions for efficient spin injection from a ferromagnetic
metal into a semiconductor,” Phys. Rev. B, vol. 64, p. 184420, 2001.
[29] E. I. Rashba, “Theory of electrical spin injection: Tunnel contacts as a solution
of the conductivity mismatch problem,” Phys. Rev. B, vol. 62, p. R16267, 2000.
[30] G. Schmidt, D. Ferrand, and L. W. Molenkamp, “Fundamental obstacle for
electrical spin injection from a ferromagnetic metal into a diffusive semiconductor,”
Phys. Rev. B, vol. 62, p. R4790, 2000.
[31] G. Schmidt and L. Molenkamp, “A loadline method for determining the efficiency
of spin injection contacts,” Semicond. Sci. Technol., vol. 19, p. 1161, 2004.
[32] A. Bachtold, M. S. Fuhrer, and S. Plyasunov, “Scanned probe microscopy of electronic transport in carbon nanotubes,” Phys. Rev. Lett., vol. 84, p. 6082, 2000.
[33] S. Frank, P. Poncharal, and Z. L.Wang, “Carbon nanotube quantum resistors,”Science, vol. 280, p. 1744, 1998.
[34] K. Takayanagi, “Suspended gold nanowires:ballistic transport of electrons,”JSAP International, vol. 3, p. 3, 2001.
[35] P. S. Robbert and H. Geisler, “Novel electronic and magnetic properties of ultrathin chromium oxide films grown on Pt(111),” J. Vac. Technology - sections a, vol. 16, p. 990, 1998.
[36] D. T. Pierce and F. Meier, “Photoemission of spin-polarized electrons from
GaAs,” Phys. Rev. B, vol. 13, p. 5484, 1976.
[37] Y. Ohno, D. K. Young, B. Beschoten, and F. Matsukura, “Electrical spin injection in a ferromagnetic semiconductor heterostructure,” Nature, vol. 402, p.790, 1999.
[38] R. J. Soulen, Jr., M. S. Osofsky, and B. Nadgorny, “Andreev reflection: A new means to determine the spin polarization of ferromagnetic materials,”App.Phys. Lett., vol. 85, p. 4589, 1999.
[39] T. Kimura, J. Hamrle, and Y. Otani, “Spin-dependent boundary resistance in the lateral spin-valve structure,” App.Phys. Lett., vol. 85, p. 3501, 2004.
[40] F. J. Jedema, A. T. Filip, and B. J. van Wees, “Electrical spin injection and accumulation at room temperature in an all-metal mesoscopic spin valve,” Nature, vol. 410, p. 345, 2001.
[41] F. J. Jedema, M. S. Nijboer, and A. T. Filip, “Spin injection and spin accumulation in all-metal mesoscopic spin valves,” Phys. Rev. B, vol. 67, p. 085319, 2003.
[42] M. Bockrath, D. H. Cobden, and P. L. McEuen, “Single-electron transport in ropes of carbon nanotubes,” Science, vol. 275, p. 1922, 1997.
[43] K. Tsukagoshi, B. W. Alphenaar, and H. Ago, “Coherent transport of electron spin in a ferromagnetically contacted carbon nanotube,” Nature, vol. 401, p.572, 1999.
[44] J. Kong, E. Yenilmez, and T. W. Tombler, “Quantum interference and ballistic transmission in nanotube electron waveguides,” Phys. Rev. Lett., vol. 87, p.106801, 2001.
[45] J.-R. Kim, H. M. So, and J.-J. Kim, “Spin-dependent transport properties in a single-walled carbon nanotube with mesoscopic co contacts,” Phys. Rev. B, vol. 66, p. 233401, 2002.
[46] B. Kubota, “Decomposition of higher oxides of chromium under various pressures
of oxygen,” J. Am. Ceram. Soc., vol. 44, p. 239, 1961.
[47] S. J. Liu and J. Y. Juang, “Transport properties of CrO2 (110) films grown on TiO2 buffered si substrates by chemical vapor deposition,” App.Phys. Lett., vol. 80, p. 4202, 2002.
[48] X. W. Li, A. Gupta, and G. Xiao, “Influence of strain on the magnetic properties
of epitaxial (100) chromium dioxide (CrO2) films,” App.Phys. Lett., vol. 75, p.713, 1999.
[49] X. W. Li and A. Gupta, “Magnetoresistance and hall effect of chromium dioxide epitaxial thin films,” J. Appl. Phys., vol. 85, p. 5585, 1999.
[50] L. Ranno and A. Barry, “Production and magnetotransport properties of CrO2
films,” J. Appl. Phys., vol. 81, p. 5774, 1997.
[51] S. Ishibashi, “Epitaxial growth of ferromagnetic CrO2 films in air,” Mat. Res.
Bull., vol. 14, p. 51, 1979.
[52] K.suzuki and P. Tedrow, “Selective deposition of CrO2 films on glass substrates,”
Solid State Commu., vol. 107, p. 583, 1998.
[53] A. Guptaa, X. W. Li, and S. Guha, “Selective-area and lateral overgrowth of
chromium dioxide (CrO2) films by chemical vapor deposition,” App.Phys. Lett.,
vol. 75, p. 2996, 1999.
[54] S. L. Flegler, J. John W. Heckman, and K. L. Klomparens, Scanning and transmission
electron microscopy, 1993.