目前有機薄膜電晶體越來越收歡迎的原因為低溫製程、低製造成本、元件輕薄、製程簡單。應用於日常生活中之產品如無線射頻身份證、電子紙、電子標籤。若能提高其載子移動率與穩定性，在未來可作為驅動元件或開關之用。
雖然有機薄膜電晶體具有低溫製程、低製造成本、可製作在可撓曲之基板的好處，但它的高操作電壓及低電子移動率使得有機薄膜電晶體在能實際應用之前仍有相當的改進空間。本論文針對改善元件載子移動率提出新的表面處理方式：N2O電漿 (N2O-plasma)、 UV/Ozone、 UV/Ozone+hexamethyldisilazane (HMDS)，本論文成功的以下接觸式結構 (bottom Contact) ，使用熱蒸鍍方式成長有機薄膜，在重摻雜矽基板上製作出以 pentacene 為主動層， SiO2 為閘極絕緣層，鉑/鉻為金屬電極的有機薄膜電晶體。為了符合有機元件低溫製程的趨勢，我們採用高密度電漿化學氣相沉積系統 (HDP-CVD) 製作之 SiO2 當為閘極絕緣層，我們發現以 HDP-CVD 製作之 SiO2 所完成之元件呈現出較差的特性。其電子移動率 μ = 7.69×10-3 cm2/V-s，起始電壓 Vt = - 11 V，ION/IOFF = 7.24×104，sub-threshold slope = 6.66 V/decade。 N2O-Plasma 、 UV/Ozone 、 UV/Ozone+HMDS 主要處理介電層表面，在 N2O-Plasma 處理方式中我們成功地改善元件特性。其電子移動率 μ = 1.17×10-2 cm2/V-s，起始電壓 Vt = - 8 V ，開關電流比 ION/IOFF = 5.50×105 ，次臨界斜率 sub-threshold slope = 6.33 V/decade。
我們利用原子力顯微鏡(Atomic Force Microscope, AFM )觀察晶粒狀態，半導體參數分析儀 (HP4156A) 做電性量測分析。雖然利用表面處理方式能夠改善元件電性，但是，有機薄膜電晶體的特性仍然有待進一步改善。

Organic thin-film transistors (OTFTs) have attracted much attention by the low temperature process, low cost, simple process,etc. For product application : RFID, electronics paper, electronics tag etc. If we improve the low electron mobility and stability, it can be applied to driving device or switch in the future.
Although organic thin film transistors have the advantages of low cost, low manufacturing temperature, being able to fabricated on flexible substrate, they suffers from high operating voltages and low electron mobility. These problems with the organic thin film transistors make them yet apply to practical applications. In this thesis, we successfully fabricated organic thin film transistors on the Si substrate with SiO2 Oxide as gate dielectric. In which, evaporated pentacene is used as the active layer, Pt/Cr is used as the Source/Drain . SiO2 Oxide is manufactured by HDP-CVD in order to conform low temperature process trend, but we got bad performance. An electron mobility of μ = 7.69×10-3 cm2/V-s, a threshold voltage of Vt = - 11 V, an ION/IOFF ratio of 7.24×104, and a sub-threshold slope of 6.66 V/decade are obtained. We use novel process N2O-plasma, UV/Ozoneand UV/Ozone+hexamethyldisilazane (HMDS) to improve performance. N2O-plasma treated oxide surface and then we improved electron mobility of μ = 1.17×10-2 cm2/V-s, Vt = - 8 V, ION/IOFF = 5.50×105, S.S = 6.33 V/decade, successfully. Using Atomic Force Microscope (AFM) and HP4156A to analyze grain size, grain boundary and electronic characteristic. Although we improve device performance by surface treatment, properties of organic thin film transistor need further improved in the future.

[1]O. Satoru, C. Takashi, M. Satoshi, S. Hideo, T. Takahisa, O. Yoshiyuki, and T. Masami, “Active Matrix Driving Organic Light-Emitting Diode Panel Using Organic Thin-Film Transistors,” J. J. Appl. Phys. vol.44, no.6A, pp.3678–3681, 2005.

[2]B. Yoo, T. Jung, D. Basu, and A. Dodabalapur “High-mobility bottom-contact n-channel organic transistors and their use in complementary ring oscillators,” Appl. Phys. Lett. vol.88, pp.82-104, 2006.

[3]L. Zhou, , S. Park, B. Bai, J. Sun, W. Sheng-Chu,Thomas N. Jackson, S.Nelson, D. Freeman, and Y. Hong, Member, IEEE “Pentacene TFT Driven AM OLED Displays,” IEEE Electron Device Lett., vol.26, no.9, pp.640-642, 2005.

[4]A. Tsumura, H. Koezuka, T. Ando, “Macromolecular electronic device: Field-effect transistor with a polythiophene thin film,” Appl. Phys. Lett., vol.49, no.18, pp.1210-1212, 1986.

[5]A. Assadi, C. Svensson, M. Willander, O. Ingans, “Field-effect mobility of poly(3-hexylthiophene),” Appl. Phys. Lett., vol.53, no.3, pp.195-197, 1988.

[6]J. Paloheimo, E. Punkka, H. Stubb, P. Kuivalainen, “In Lower Dimensional Systems and Molecular Devices,” Proceedings of NATO ASI, Spetses, Greece (Ed: R. M. Mertzger), Plenum, New York 1989.

[7]Z. Bao, A. Dodabalapur, A. J. Lovinger, “Soluble and processable regioregular poly(3-hexylthiophene) for thin film field-effect transistor applications with high mobility,” Appl. Phys. Lett., vol.69, no.26, pp.4108-4110, 1996.

[8]H. Sirringhaus, N. Tessler, R. H. Friend, Science, vol.280, pp.1741-1742, 1998.

[9]C. D. Dimitrakopoulos and D. J. Mascaro, Organic thin-film transistors: A review of recent advances,” IBM, vol. 45, pp.11-27, 2001.

[10]A. R. Brown, A. Pomp, D. M. de Leeuw, D. B. M. Klassen, E. E. Havinga, P. T. Herwig, and K. Müllen, “Precursor route pentacene metal-insulator-semiconductor field-effect transistors,” J. Appl. Phys. vol.79, pp.2136-2138, 1996.

[11]Z. T. Zhu, J. T. Mason, R. Dieckmann, and G. G. Malliaras, “Bulk and surface magnetic study of Fe80B20 crystallization,” Appl. Phys. Lett. Vol.81, pp.4643-4645, 2002.

[12]S. F. Nelson, Y. Y. Lin, D. J. Gundlach, and T. N. Jackson, “Temperature-independent transport in high-mobility Pentacene transistors,” Appl. Phys. Lett., vol.72, pp.1854-1856, 1998.

[13]A. R. Brown, C. P. Jarrett, D. M. de Leeuw, and M. Matters, “Field-effect transistors made from solution-processed organic semiconductors,” Synthetic Metals, vol.88, pp.8137-8155, 1997.

[14]K. Nomoto, N. Hirai, N. Yoneya, N. Kawashima, M. Noda, M. Wada, and J. Kasahara,“A high-performance short-channel bottom-contact OTFT and its application to AM-TN-LCD,” IEEE Trans. Electron Devices vol.52, pp.1519-1526, 2005.

[15]M. Baldo, M. Deutsch, P. Burrows, H. Gossenberger, M. Gerstenberg, V. Ban, and S.Forrest, “Organic Vapor Phase Deposition, ” Adv. Mater. vol.10, no.18, pp.234-238, 1998.

[16]C D. Dimitrakopoulos*, and Patrick R. L. Malenfant, “Organic Thin Film Transistors for Large Area Electronics,” Adv. Mater. vol.14, no.2, 2002.

[17]H. Sirringhaus, P. J. Brown, R. H. Friend et al., Nature (London) vol.401, pp.685, 1999.

[18]A. R. Brown, C. P. Tarrett, D. M. de Leeuw and M. Matters, “Field-effect transistors made from solution-processed organic semiconductors, ” Synth. Met., vol.88, pp.37-55, 1997.

[19]P. G. Le Comber, and W. E. Spear, “ Electronic Transport in Amorphous Silicon Films,” Phys. Rev. Lett., vol.25, pp.509-511, 1970.

[20]G. Horowitz, and P. Delannoy, “An analytical model for organic-based thin-film transistors, ” J. Appl. Phys., vol.70, pp.469-475, 1991.

[21]G. Horowitz, R. Hajlaoui, and P. Delannoy, “Temperature dependence of the Field-effect mobility of sexithiophene. Determination of the density of traps, ” J. Phys. III, vol.5, pp.355-371, 1995.

[22]A. R. Brown, D. M. de Leeuw, E. E. Havinga, and A. Pomp, “A universal relation between conductivity and field-effect mobility in doped amorphous organic semiconductors, ”Synth. Met., vol.68, pp.65-70, 1994.

[23]M. C. J, M. Vissenberg, and M. Matters, “Theory of the field-effect mobility in amorphous organic transistors,” Phys. Rev. B, vol.57, pp.12964-12967, 1998.

[24]T. Mizuki, J.S. Matsuda, Y. Nakamura, J. Takagi, and T. Yoshida, “Large domains of continuous grain silicon on glass substrate for high-performance TFTs,” IEEE Trans.Electron Devices, vol.51, pp.204-211, 2004.

[25]E. M. Suuberg, “Vapor pressures and enthalpies of solution of polycyclic aromatic hydrocarbons and their derivatives,” J. Chem. Eng. Data, vol.43, no.3, pp.486–492, 1998.

[26]Yuuma Suzue, Takaaki Manaka, and Mitsumasa Iwamoto, “Current-Voltage Characteristics of Pentacene Films: Effect of UV/Ozone Treatment on Au Electrodes, ” J. J. Appl.Phys. vol.44, No.1B, pp.561–565, 2005.

[27]T. C. Gorjanc, I. Le´vesque, M. D’Iorio, “Organic field effect transistors based on modified oligo-p-phenylevinylenes,” Appl. Phys. Lett., vol.84, pp.930-932, 2004.

[28]Y. C. Chen, M. Z. Yang, I. C. Tung, M. Chen, M. S. Feng, H. C. Heng, and C. Y. Chang, “Effects of O2-plasma and N2O-Plasma Treatments on Properties of Plasma-Enhanced-Chemical-Vapor-Deposition Tetraethylorthosilicate Oxide, ” Jpn. J. Appl.Phys. vol.38, pp.4226-4232, 1999.

[29]Ito Takashi, Nakamura Tetsuo, Ishikawa Hajime, “Advantages of thermal nitride and nitroxide gate films in VLSI process,” IEEE Trans Electron Dev, vol. ED-29, pp.498-502, 1982.