The CNT network is formed by spin-coating CNT solution on the substrate rather than grown on the substrate directly. That would avoid the substrate of CNTN TFT exposing to high temperature and then various substrates such as plastic substrate could be compatible with flexible and display process. The transport and flexible CNTN TFTs could be fabricated.
In order to improve on/off ratio, in addition to applying electrical breakdown method to selectively remove metallic CNTs, there are a variety of techniques including reducing the diameter of CNTs during CNT grow to increase the band gap of CNTs or separating metallic CNTs from semiconducting CNTs to suppress leakage current.
The mobility and on-state current improvement could be done by precisely
80
assembling an array of parallel semiconducting CNTs to enhance the drive current rather than randomly spreading CNTs. Since purity of 50% to 70% of CNT was used in thesis, using purity > 90% of CNT could also enhance mobility. In addition, decreasing the geometrical rise of bottom gate is also feasible to improve CNT coverage uniformity.
The determination of percolation threshold was done by performing Monte Carlo simulation. The random CNT networks were generated to examine the conducting path formation. Next step is assigning each CNT interaction a contact resistance and then the resistivity of CNT networks could be done by dividing the voltage drop between S/D contacts by total current flowing in conducting paths.
81
References
[1]. H. W. Kroto, J. R. Heath, S. C. O’Brien, R. F. Curl and R. E. Smalley, “C60:
buckministerfullerene”, Nature, vol. 318, pp. 162-163, 1985.
[2]. S. Iijima, “Helical microtubules of graphitic carbon”, Nature, vol. 354, pp. 56-58, 1991.
[3]. S. Iijima and T. Ichihashi, “Single-shell carbon nanotubes of 1-nm diameter”, Nature, vol. 363, pp. 603-605, 1993.
[4]. T. Wang Odom, J. Huang, P. Kim, and C. M. Lieber, “Atomic structure and electronic properties of single-walled carbon nanotubes”, Nature, vol. 391, pp.
62-64, 1998.
[5]. R. Sen, B. C. Satishkumar, G. Raina, and C. N. R. Rao, “Structures and images of novel derivatives of carbon nanotubes, fullerenes and related new carbon forms”, Taylor & Francis: Oxford, 1997.
[6]. J. W. G. Wildo, L. C. Venema, A. G. Rinzler, R. E. Smalley, and C. Dekker,
“Electronic structure of atomically resolved carbon nanotubes” , Nature, vol. 391, pp. 59-62, 1998.
[7]. P. Avouris, J. Appenzeller, R. Martel, and S. J. Wind, “Carbon Nanotube Electronics”, Proceedings of the IEEE, vol. 91, 2003.
[8]. R. Saito, M. Fujita, G. Dresselhaus, and M. S. Dresselhaus, “Electronic structure of chiral graphene tubules”, Appl. Phys. Lett., vol. 60, pp. 2204–2206, 1992.
[9]. R. Saito, M. Fujita, G. Dresselhaus, and M. S. Dresselhaus, “Electronic structure of graphene tubules based on C60”, Phys. Rev. B, vol. 46, pp. 1804–1811, 1992.
[10]. A. Rakitin, C. Papadopoulos, and J. M. Xu, “Electronic properties of amorphous carbon nanotubes”, Phys. Rev. B, vol. 61, pp. 5793-5796, 2000.
[11]. T. W. Ebbesen, and P. M. Ajayan, “Large-scale synthesis of carbon nanotubes”, Nature, vol.358, pp. 220-222, 1992.
[12]. T. Guo, P. Nikolaev, A. Thess, D.T. Colbert, and R.E. Smalley, "Catalytic growth of single-walled nanotubes by laser vaporization", Chem. Phys. Lett., vol. 243, pp. 49-54, 1995
[13]. A. Thess, R. Lee, P. Nikolaev, H. Dai, P. Petit, J. Robert, C. Xu, Y.H. Lee, S.G.
Kim, A.G. Rinzler, D.T. Colbert, G.T. Scuseria, D. Tomanek, J.E. Fischer, and R.E. Smalley, “Crystalline Ropes of Metallic Carbon Nanotubes”, Science, vol.
273, pp. 483-487, 1996.
[14]. M. José-Yacamán, M. Yoshida, and L. Rendón, "Catalytic growth of carbon microtubules with fullerene structure", Appl. Phys. Lett., vol. 62, pp. 202-204,
82
1993.
[15]. N. Inami, M.A. Mohamed, E. Shikoh, and A. Fujiwara, "Synthesis-condition dependence of carbon nanotube growth by alcohol catalytic chemical vapor deposition method", Sci. Technol. Adv. Mater., vol. 8, pp. 292-295, 2007.
[16]. C. Bower, O. Zhou, W. Zhu, D.J. Werder, and S. Jin, “Nucleation and growth of carbon nanotubes by microwave plasma chemical vapor deposition”, Appl. Phys.
Lett., vol. 77, pp. 2767-2769, 2000.
[17]. Y. Li, D. Mann, M. Rolandi, W. Kim, A. Ural, S. Hung, A. Javey, J. Cao, D.
Wang, E. Yenilmez, Q. Wang, J. F. Gibbons, Y. Nishi, and H. Dai, “Preferential growth of semiconducting single-walled carbon nanotubes by a plasma enhanced CVD method”, Nano Lett., vol. 4, pp. 317-321, 2004.
[18]. A. Ural, Y. Li, and H. Dai, “Electric-field-aligned growth of single-walled carbon nanotubes on surfaces”, Appl. Phys. Lett., vol. 81, pp. 3464-3466, 2002.
[19]. G. Zhang, X. Wang, X. Li, Y, Lu, A. Javey, and H. Dai, “Carbon nanotubes:
from growth, placement and assembly control to 60 mV/decade and sub-60 mV/decade tunnel transistors”, in IEDM Tech. Dig., pp. 431-434, 2006.
[20]. M. A. Meitl, Y. Zhou, A. Gaur, S. Jeon, M. L. Usrey, M. S. Strano, and J. A.
Rogers, “Solution casting and transfer printing single-walled carbon nanotube films”, Nano Lett, vol. 4, pp. 1643-1647, 2004
[21]. Y. Zhou, A. Gaur, S. H. Hur, C. Kocabas, M. A. Meitl, M. Shim, and J. A.
Rogers, “p-channel, n-channel thin film transistors and p-n diodes based on single wall carbon nanotube networks,” Nano Lett., vol.4, pp.2031-2035, 2004.
[22]. Z. Chen, J. Appenzeller, Y.M. Lin, J. Sippel-Oakley, A. G. Rinzler, J. Tang, S. J.
Wind, P. M. Solomon, and P. Avouris, “An integrated logic circuit assembled on a single carbon nanotube”, Science, vol. 311, p. 1735, 2006.
[23]. Z.Wu, Z. Chen, X. Du, J. M. Logan, J. Sippel, M. Nikolou, K. Kamaras, J. R.
Reynolds, D. B. Tanner, A. F. Hebard, A. G. Rinzler, “Transparent, conductive carbon nanotube films”, Science, vol. 305, pp. 1273-1276, 2004.
[24]. Z. Li, P. Dharap, S. Nagarajaiah, E. V. Barrera, and J. D. Kim, “Carbon nanotube film sensors”, Adv. Mater., vol. 16, pp. 640-643, 2004
[25]. J. K. Abraham, B. Philip, A. Witchurch, V. K. Varadan, and C. C. Reddy, “A compact wireless gas sensor using a carbon nanotube/PMMA thin film chemiresistor”, Smart Mater. Struct., vol. 13, pp. 1045-1049, 2004.
[26]. M, E. Roberts, M, C. LeMieux, and Z, Bao, “Sorted and Aligned Single-Walled Carbon Nanotube Networks for Transistor-Based Aqueous Chemical Sensors,“ ACS Nano, vol. 3, pp. 3287–3293, 2009.
[27]. E. Gui, L. J. Li, K. Zhang, Y. Xu, X. Dong, X. Ho, P. S. Lee, J. Kasim, Z. X.
Shen, J. A. Rogers and J. Mhaisalkar, “DNA Sensing by Field Effect Transistors
83
Based on Networks of Carbon Nanotubes”, J. Am. Chem. Soc., vol. 129, pp.
14427-14432, 2007.
[28]. X. Tang, S. Bansaruntip, N. Nakayama, E. Yenilmez, Y. Chang and Q. Wang,
“Carbon Nanotube DNA Sensor and Sensing Mechanism”, Nano Lett., vol. 6, pp.
1632-1636, 2006.
[29]. S. Hong, and S. Myung, "Nanotube electronics: a flexible approach to mobility", Nature, vol. 2, pp. 207-208, 2007.
[30]. J. Hone, M. Whitney, C. Piscoti, and A. Zettl, “Thermal conductivity of single-walled carbon nanotubes”, Phys. Rev. B, vol. 59, pp. R2514-R2516, 1999.
[31]. E. Pop, D. Mann, Q. Wang, K. Goodson, and H. Dai, "Thermal conductance of an individual single-wall carbon nanotube above room temperature", Nano Lett., vol. 6, pp. 96-100, 2006
[32]. M. R. Falvo, G. J. Clary, R. M. Taylor II, V. Chi, F. P. Brooks Jr, S. Washburn, and R. Superfine, “Bending and bucking of carbon nanotubes under large strain”, Nature, vol. 389, pp. 582-584, 1997.
[33]. E. W. Wong, P. E. Sheehan, and C. M. Lieber, “Nanobeam mechanics: elasticity, strengthand toughness of nanorods and nanotubes”, Science, vol. 227, pp.
1971-1975, 1997.
[34]. R. Martel, T. Schmidt, H. R. Shea, T. Hertel, and P. Avouris, “Single-and multi wall carbon nanotube field-effect transistors”, Appl. Phys. Lett., vol. 73, pp.
2447-2449, 1998.
[35]. S. J. Tans, A. R. M. Verschueren, and C. Dekker., “Room-temperature transistor based on a single carbon nanotube”, Nature, vol. 393, pp. 49-52, 1998.
[36]. T. Durkop, S. A. Getty, E. Cobas, and M. S. Fuhrer, “Extraordinary Mobility in Semiconducting Carbon Nanotubes,” Nano Lett., vol. 4, pp.35-38, 2004.
[37]. A. Javey, J. Guo, Q. Wang, M. Lundstrom, and H. Dai, “Ballistic carbon nanotube field-effect transistors”, Nature, vol. 424, pp. 654-657, 2003.
[38]. S. J. Tans, A. R. M. Verschueren, and C. Dekker, “Room-temperature transistor based on a single carbon nanotube,” Nature, vol. 393, pp. 49-52, 1998.
[39]. A. Javey, J. Guo, D. B. Farmer, Q. Wang, D. Wang, R. G. Gordon, M.
Lundstrom, and H. Dai, “Carbon Nanotube Field-Effect Transistors with Integrated Ohmic Contacts and High-k Gate Dielectrics,” Nano Lett., vol. 4, pp.447-450, 2004.
[40]. R. Martel, V. Derycke, C. Lavoie, J. Appenzeller, K. Chan, J. Tersoff, and P.
Avouris, “Ambipolar Electrical Transport in Semiconducting Single-Wall Carbon Nanotubes”, Phys. Rev. Lett., vol. 87, pp. 256805-256808, 2001.
[41]. V. Derycke, R. Martel, J. Appenzeller, and P. Avouris, “Carbon nanotube inter- and intramolecular logic gates”, Nano Lett., vol. 1, pp. 453-456, 2001.
84
[42]. M. Bockrath, J. Hone, A. Zettl, P. L. McEuen, A. G. Rinzler, and R. E. Smalley, “Chemical doping of individual semiconducting carbon-nanotube ropes”, Phys.
Rev. B, vol. 61, pp. 10606 -10608, 2000.
[43]. M. Shim, A. Javey, N. Wong, S. Kam, and H. Dai, “Polymer functionalization for air-stable n-type carbon nanotube field-effect transistors,” J. Am. Chem. Soc., vol.123, pp.11512-11513, 2001.
[44]. S. Heinze, J. Tersoff, R. Martel, V. Derycke, J. Appenzeller, and P. Avouris,
“Carbon Nanotubes as Schottky Barrier Transistors,” Phys. Rev. Lett., vol.89, pp.106801-1-106801-4, 2002.
[45]. Z. Chen, J. Zppenzeller, J. Knoch, Y.M. Lin, and P.n Avouris,“The role of metal-nanotube contact in the performance of carbon nanotube field-effect transistors,” Nano Lett., vol.5, pp.1497-1502, 2005.
[46]. Y. Zhang and H. Dai, “Formation of metal nanowires on suspended
single-walled carbon nanotubes,” Appl. Phys. Lett., vol.77, pp.3015-3017, 2000.
[47]. O.K. Varghese, P. D. Kichambre, D. Gong, K. G. Ong, E. C. Dickey, and C. A.
Grimes, “Gas sensing characteristics of multi-wall carbon nanotubes” Sensors and Actuators B, vol.81, pp.32-41,2001.
[48]. K. Bradley, J. C. P. Gabriel, M. Briman, A. Star, and G. Gruner, “Charge Transfer from Ammonia Physisorbed on Nanotubes” Phys. Rev. Lett., vol.91, pp.218301-1-218301-4, 2003.
[49]. J. Kong, M. G. Chapline, and H. Dai, “Functionalized Carbon Nanotubes for Molecular Hydrogen Sensors,”, Adv. Mater., vol.13, pp.1384-1386, 2001.
[50]. W. Kim, A. Javey, O. Vermesh, Q. Wang, Y. Li, and H. Dai,“Hysteresis
caused by water molecules in carbon nanotube field-effect transistors,” Nano Lett., vol.3, pp.193-198, 2003.
[51]. A. Zahab, L. Spina, and P. Poncharal “Water-vapor effect on the electrical conductivity of a single-walled carbon nanotube mat,” Phys. Rev. B, vol.63, pp.10000-10003, 2000.
[52]. S.J. Han, J. Chang, A.D. Franklin, A.A. Bol, R. Loesing, D. Guo, G.S. Tulevski, W. Haensch, and Z. Chen, “Wafer Scale Fabrication of Carbon Nanotube FETs with Embedded Poly-gates,” in IEDM Tech. Dig., pp. 206-209, 2010.
[53]. S. Suzuki, and Y. Kobayashi, “Conductivity Decrease in Carbon Nanotubes Caused by Low-Acceleration-Voltage Electron Irradiation ”, Japanese Journal of Appl. Phys., vol. 44, pp. L1498-L1501, 2005.
[54]. C. Jin, K. Suenaga, and S. Iijima, “Vacancy migrations in carbon nanotubes,”
Nano Lett., vol.8, pp.1127-1130, 2008.
[55]. X. Duan, C. Niu, V. Sahi, J. Chen, J. W. Parce, S. Empedocles, and J. L.
Goldman,“High-performance thin-film transistors using semiconductor
85
nanowires and nanoribbons,” Nature, vol.425, pp.274-278, 2003.
[56]. Y. Huang, X. Duan, Q. Wei, and C. M. Lieber, “Directed assembly of
one-dimensional nanostructures into functional networks,” Nature, vol.291, pp.
630-633, 2001.
[57]. H. Xin, and A. T. Woolley, “Directional orientation of carbon nanotubes on surfaces using a gas flow cell,” Nano Lett., vol.4, pp.1481-1484, 2004.
[58]. H. Ko, and V.V. Tsukruk, “Liquid-crystalline processing of highly oriented carbon nanotube arrays for thin-film transistors,” Nano Lett., vol.6, p.1443-1448, 2006.
[59]. M. Engel, J. P. Small, M. Steiner, M. Freitag, A. A. Green, M. C. Hersam,
and P. Avouris, “Thin film nanotube transistors based on self-assembled, aligned, semiconducting carbon nanotube arrays”, ACS Nano, vol. 2, pp. 2445–2452, 2008
[60]. W. J. Yu, U. J. Kim, B. R. Kang, H. Lee, E. H. Lee, and Y. H. Lee, “Adaptive logic circuits with doping-free ambipolar carbon nanotube transistors”, Nano Lett., vol. 9, pp. 1401-1405, 2009.
[61]. A. D. Franklin, A. Lin, H.-S. Philip Wong, and Z. Chen, “Current Scaling in Aligned Carbon Nanotube Array Transistors With Local Bottom Gating,“ IEEE Elec. Dev. Lett., vol.31, pp.644-646, 2010.
[62]. N. Patil, A. Lin, E. R. Myers, K. Ryu, A. Badmaev, C. Zhou, H.S. P. Wong, and S. Mitra, “Wafer-scale growth and transfer of aligned single-walled carbon nanotubes,” IEEE Trans. Nanotechnol., vol. 8, pp. 498–504, 2009.
[63]. E. S. Snow, J. P. Novak, P. M. Campbell, and D. Park, “Random networks of carbon nanotubes as an electronic material,” Appl. Phys. Lett., vol.82, pp.2145-2147, 2003.
[64]. E. S. Snow, P. M. Campbell, M. G. Ancona, and J. P. Novak,“High-mobility carbon-nanotube thin-film transistors on a polymeric substrate”, Appl. Phys.
Lett., vol.86, pp. 033105-1-033105-3, 2005.
[65]. Y. Zhou, L. Hu, and G. Grüner, “A method of printing carbonnanotube thin films,” Appl. Phys. Lett., vol.88, pp.123109-1-123109-3, 2006.
[66]. Z. Dai, L. Yan, S. M. Alam, J. Feng, P. R. D. Mariathomas, Y. Chen, C. M. Li, Q. Zhang, L.J. Li, K. H. Lim, and M. B. Chan-Park, “Selective Small-Diameter Metallic Single-Walled Carbon Nanotube Removal by Mere Standing with Anthraquinone and Application to a Field-Effect Transistor”, J. Phys. Chem. C, vol. 114, pp. 21035-21041, 2010.
[67]. C. Wang, J. Zhang, K. Ryu, A. Badmaev, L. G. D. Arco, and C. Zhou,
“Wafer-scale fabrication of separated carbon nanotube thin-film transistors for display applications”, Nano Lett., vol. 9, pp. 4285-4291, 2009.
86
[68]. K.C. Narasimhamurthy and R. Paily, “High-performance local back gate
thin-film field-effect transistors using sorted carbon nanotubes on an amino-silane treated hafnium oxide surface”, Semicond. Sci. Technol, vol. 26, pp.
075002-1-075002-11, 2011.
[69]. G. E. Pike and C. H. Seager, “Percolation and conductivity L A computer study.
I,” Phys. Rev. B, vol. 10, pp. 1421-1434, 1974.
[70]. C. H. Seager and G. E. Pike, “Percolation and conductivity L A computer study.
II,” Phys. Rev. B, vol. 10, pp.1435-1446, 1974.
[71]. Y.B. Yi and A. M. Sastry, “Analytical approximation of the two-dimensional percolation threshold for fields of overlapping ellipses”, Phys. Rev. E., vol. 66, pp. 066130-1-066130-8, 2002.
[72]. J. N. Coleman, S. Curran, A. B. Dalton, A. P. Davey, B. McCarthy, W. Blau, and R. C. Barklie, "Percolation-dominated conductivity in a conjugated polymer carbon nanotube composite," Phys. Rev. B., vol. 58, pp. R7492-R7495, 1998.
[73]. L. Hu, D. S. Hecht, and G. Gru1ner, “Percolation in Transparent and Conducting Carbon Nanotube Networks,” Nano Lett., vol. 4, pp.2513-2517, 2004.
[74]. H. E. Unalan, G. Fanchini, A. Kanwal, A. D. Pasquier, and M. Chhowalla,
“Design Criteria for Transparent Single-Wall Carbon Nanotube Thin-Film Transistors,” Nano Lett., vol.6, pp. 677-682, 2006.
[75]. S. Kumar, J.Y. Murthy, and M. A. Alam,, “Percolating conduction in finite nanotube networks,” Phys. Rev. Lett., vol. 95, pp. 066802-1-066802-4, 2005.
[76]. A. Behnam and A. Ural, "Computational study of geometry-dependent
resistivity scaling in single-walled carbon nanotube films," Phys. Rev. B, vol. 75, pp. 125432-1-125432-8, 2007.
[77]. J. Hicks, A. Behnam, and A. Ural, “Resistivity in percolation networks of one-dimensional elements with a length distribution”, Phys. Rev. E, vol. 79, pp.
012102-1-012102-4, 2009.
[78]. S. Seppälä, E. Häkkinen, M. J. Alava, V. Ermolov and E. T. Seppälä, “Electrical transport properties of percolating random networks of carbon nanotube bundles,”
EPL, vol. 91, pp.47002-1-47002-6, 2010.
[79]. V. K. Sangwan, A. Behnam, V. W. Ballarotto, M. S. Fuhrer, A. Ural, and E. D.
Williams, “Optimizing transistor performance of percolating carbon nanotube networks,” Appl. Phys. Lett., vol.97, pp. 043111-1-043111-3, 2010.
[80]. G. Zhang, P. Qi, X. Wang, Y. Lu, X. Li, R. Tu, S. Bangsaruntip, D. Mann, L.
Zhang, H. Dai, ”Selective Etching of Metallic Carbon Nanotubes by Gas-Phase Reaction”, Science, vol. 314, pp. 974-977, 2006.
[81]. D. B. Farmer and R. G. Gorden, “ALD of high-k dielectrics on suspended Functionalized SWNTs”, Electrochemical and Solid-State Letters, vol. 8, pp.
87
89-91, 2005.
[82]. D. B. Farmer and R. G. Gorden, “Atomic layer deposition on suspended
single-walled carbon nanotubes via gas-phase noncovalent functionalization”, Nano Lett., vol. 6, pp. 699-703, 2006.
[83]. The dielectric constant of Al2O3 and HfO2 are determined by Dr. Jiun-Rung Su, nano facility center (NFC) researcher.
[84]. C. D. Dimitrakopoulos and P. R. L. Malenfant, “Organic thin film transistors for large area electronics”, Adv. Mater., vol. 14, pp. 99-117, 2002.
[85]. G.H. Gelinck, H.E.A. Huitema, E.V. Veenendaal, E. Cantatore, L.Schrijnemakers, J.B.P.H. Van Der Putten, T.C.T. Geuns, M. Beenhakkers, J.B.
Giesbers, B.H. Huisman, E.J. Meijer, E.M. Benito, F.J. Touwslager, A.W.
Marsman, B.J.E. Van Rens, and D.M. De Leeuw, “Flexible active-matrix displays and shift registers based on solution-processed organic transistors”, Nat.
Mater., vol. 3, pp. 106-110, 2004.
88