本研究利用熱燈絲化學氣相沉積法成長具片狀結構的奈米微晶石墨薄膜，改變製程參數如氣體比例、成長溫度、添加氮氣及對基板進行前處理，討論各參數條件下奈米石墨的表面形貌、均勻度、結晶品質與場發射效果。接著，利用熱燈絲化學氣相沉積法及微波電漿輔助化學氣相沉積法分別成長出奈米石墨與超奈米鑽，製作出超奈米鑽/奈米石墨複合薄膜並探討各項特性。最後，利用黃光微影技術、非等向性蝕刻技術及成型技術製作具尖端結構場發射元件，量測元件各項性質並比較場發射效果。
在本研究中，甲烷濃度9%成長出來的奈米石墨，場發射起始電場為12.3 V/μm，經氮氣摻雜後場發射起始電場降至約6~8 V/μm。超奈米鑽石/奈米石墨複合薄膜，起始電場在約6~7 V/μm，並由於鑽石高導熱性及結構強度保護下層奈米石墨，經多次量測仍保有高電流強度，具有相當好的再現性。而利用成形技術複刻出針端場發射陣列，製作出尖端結構增進場增益因子，結構高度為8.4 μm，底邊長度為12 μm，針尖間距與高度比值為3，量測到4~6 V/μm的起始電場並擁有高電流密度。本研究討論多種奈米微晶石墨薄膜的場發射特性，期望對場發射元件的開發上有所貢獻。

In our research, flake-like nanocrystalline graphite(NCG) films were grown on the silicon substrate using hot-filament chemical vapor deposition(HFCVD) system. We observed NCG’s surface morphology, uniformity, crystal quality and measured their field emission properties after changing process parameters like gas ratio, growth temperature, adding nitrogen and using pretreatment. Afterward we fabricated the Ultra-nano crystalline diamond(UNCD) and NCG composite films and discussed their properties. Finally, we fabricated NCG, UNCD and UNCD/NCG pyramid-type field emission arrays by using lithography technique, anisotropic etching technique and molding technique. The experimental showed that the turn-on field on the NCG film grown by using 9% methane concentration was 12 V/μm. After adding nitrogen, the turn-on field decreased to about 6~8 V/μm. The turn-on field on the UNCD/NCG composite films were about6~7 V/μm. We observed the reproducibility on UNCD/NCG composite films’ field emission behavior due to the high thermal conductivity and mechanical strength on UNCD. For improving the field emission facter, we fabricated the pyramid-type field emission arrays. They were 8.4 μm in height, 12 μm in base length and 3 in the pitch to base length ratio . The lowest turn-on field of 4.78 V/μm can be obtained in NCG pyramid-type field emission arrays.

[1] R. H. Fowler and L. Nordheim, “ Electron Emission in Intense Electric Fields,” Proceedings of the Royal Society of London. Series A, VOL.119, pp.173-181, 1928.
[2] J. He, P. H. Cutler, and N. M. Miskovsky, “Generalization of Fowler–Nordheim field emission theory for nonplanar metal emitters,” Applied Physics Letters, vol.59, pp.1644-1646, 1991.
[3] K. L. Jensen and E. G. Zaidman, “Field emission from an elliptical boss: Exact versus approximate treatments,” Journal of Applied Physics, vol.63, p.702, 1993.
[4] K. L. Jensen and E. G. Zaidman, “Field emission from an elliptical boss: Exact and approximate forms for area factors and currents,” Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, vol.12, p.776, 1994.
[5] K. L. Jensen and E. G. Zaidman, “Analytic expressions for emission in sharp field emitter diodes,” Journal of Applied Physics, vol.77, pp. 3569-3571, 1995.
[6] T. S. Fisher, “Influence of nanoscale geometry on the thermodynamics of electron field emission,” Applied Physics Letters, vol.79, p.3699, 2001.
[7] T. S. Fisher and D. G. Walker, “Thermal and Electrical Energy Transport and Conversion in Nanoscale Electron Field Emission Processes,” Journal of Heat Transfer, vol.124, pp.954-962, 2002.
[8] L. Nilsson, O. Groening, C. Emmenegger, O. Kuettel, E. Schaller, and L. Schlapbach, “Scanning field emission from patterned carbon nanotube films,” Applied Physics Letters, vol.76, pp.2071-2073, 2000.
[9] J. S. Suh, K. S. Jeong, and J. S. Lee , “Study of the field-screening effect of highly ordered carbon nanotube arrays,” Applied Physics Letters, vol.80, pp.2392-2394, 2002.
[10] R. C. Smith and S. R. P. Silva, “Maximizing the electron field emission performance of carbon nanotube arrays,” Applied Physics Letters, vol.94, pp.133104-3, 2009.
[11] Y. Wu, B. Yang, B. Zong, H. Sun, Z. Shen, and Y. Feng, “Carbon nanowalls and related materials,” Journal of Materials Chemistry, vol.14, pp.469-477, 2004.
[12] A. K. Geim and K. S. Novoselov, “The rise of graphene,” Nature Materials, vol.6, pp.183-191, 2007.
[13] Y. Ando, X. Zhao, and M. Ohkohchi, “Production of petal-like graphite sheets by hydrogen arc discharge,” Carbon, vol.35, pp.153-158, 1997.
[14] Y. Wu, P. Qiao, T. Chong, and Z. Shen, “Carbon Nanowalls Grown by Microwave Plasma Enhanced Chemical Vapor Deposition,” Advanced Materials, vol.14, pp.64-67, 2001.
[15] S. Kurita, A. Yoshimura, H. Kawamoto, T. Uchida, K. Kojima, M. Tachibana, P. Molina-Morales, and H. Nakai, “Raman spectra of carbon nanowalls grown by plasma-enhanced chemical vapor deposition,” Journal of Applied Physics, vol.97, pp. 104320-5, 2005.
[16] K. Kobayashi, M. Tanimura, H. Nakai, A. Yoshimura, H. Yoshimura, K. Kojima, and M. Tachibana, “Nanographite domains in carbon nanowalls,” Journal of Applied Physics, vol.101, pp. 094306-4, 2007.
[17] A. Malesevic, R. Kemps, A. Vanhulsel, M. P. Chowdhury, A. Volodin, and C. V. Haesendonck, “Field emission from vertically aligned few-layer graphene,” Journal of Materials Chemistry, vol.104, pp.084301-5, 2008.
[18] N. G. Shang, F. C. K. Au, X. M. Meng, C.S. Lee, I. Bello, and S. T. Lee, “Uniform carbon nanoflake films and their field emissions,” Chemical Physics Letters, vol.358, pp.187-191, 2002.
[19] T. Itoh, “Synthesis of carbon nanowalls by hot-wire chemical vapor deposition,” Thin Solid Films, vol.519, pp.4589-4593, 2011.
[20] J. Hodkiewicz, “Characterizing Carbon Materials with Raman Spectroscopy,” Thermo Fisher Scientific, 2010.
[21] D. S. Knight and W. B. White, “Characterization of diamond films by Raman spectroscopy,” Journal of Materials Chemistry, vol.4, pp.385-393, 1989.
[22] L. G. Cançado, K. Takai, T. Enoki, M. Endo, Y. A. Kim, H. Mizusaki, A. Jorio, L. N. Coelho, R. Magalhães-Paniago, and M. A. Pimenta, “General equation for the determination of the crystallite size La of nanographite by Raman spectroscopy,” Applied Physics Letters, vol.88, p.163106, 2006.
[23] A.V. Karabutov, V. G. Ralchenko, I. I. Vlasov, R. A. Khmelnitsky, M. A. Negodaev, V. P. Varnin, and I. G. Teremetskaya, “Surface engineering of diamond tips for improved field electron emission,” Diamond and Related Materials, vol.10, pp.2178-2183, 2001.
[24] K. E. Spear and J. P. Dismukes, Synthetic diamond: emerging CVD science and technology: Wiley, 1994.
[25] P. T. Joseph, N. H. Tai, Chi-Young Lee, H. Niu, W. F. Pong, and I. N. Lin, “Field emission enhancement in nitrogen-ion-implanted ultrananocrystalline diamond films,” Journal of Applied Physics, vol.103, pp. 043720-6, 2008.
[26] Y. C. Chen, X. Y. Zhong, B. Kabius, J. M. Hiller, N. H. Tai, I. N. Lin, “Improvement of field emission performance on nitrogen ion implanted ultrananocrystalline diamondfilms through visualization of structure modifications,” Diamond & Related Materials, vol.20, pp. 238-241, 2011.