臺灣博碩士論文加值系統

本論文主要內容在於研究五苯環有機薄膜電晶體搭配底接觸式結構之元件製作以及其電特性分析與改善。首先，以傳統的底接觸式結構製作固定元件通道寬度、不同元件通道長度之有機薄膜電晶體元件，發現元件特性會隨著通道長度的縮減，而有下降的趨勢，如載子移動率隨著通道長度縮減而減少。此現象與大多其他相關文獻所探討的一致，但文獻中只定性地描述此現象之機制，缺少一數學公式可以對此現象進行定量上的分析與預測。因此，我們依據此現象之機制而提出了一修改過的公式，可對底接觸式有機薄膜電晶體之特性隨著通道長度的縮減而下降，進行定量上的探討。即在底接觸式結構中，有機半導體主動層在金屬源/汲極附近成長品質較差，此主動層區域的載子移動率遠低於通道中央的移動率，此低載子移動率的主動層區域對元件整體的載子移動率計算中的權數，會隨著通道長度的縮減而增加，而使元件整體的載子移動率下降。
再者，因上述有機半導體層在底接觸式元件結構中，靠近源/汲極附近的成長品質不佳除了造成低載子移動率區域外，更導致金屬與有機半導體之間介面的載子注入效率降低而使得接觸電阻上升；並且當通道長度越短時，元件效能就會跟著進一步下降。我們針對此問題提出一個具新穎性之雙層絕緣層平面化底接觸式元件結構，此結構之源/汲極與閘極絕緣層是製作成切齊於同一個平面，讓有機半導體層可沉積在此沒有高低起伏的平面上，而改善有機半導體層在源/汲極附近的成長品質以及金半介面的載子注入效率，因此電特性獲得大幅改善。此外，為了讓有機薄膜電晶體可應用於主動式矩陣有機發光二極體顯示器面板中，達到高畫素開口率與高元件積體化密度，元件尺寸的微縮與元件效能的提升為其重點。因而我們進一步地引用雙層絕緣層平面化底接觸式元件結構，製作出次微米的有機薄膜電晶體元件，並達到傳統底接觸式結構之元件在也微縮至次微米尺寸時無法可及的高效能。
底接觸式以及底閘極結構的有機薄膜電晶體，其有機主動層位於閘極絕緣層之上，而使得有機主動層的薄膜成長品質會受到閘極絕緣層表面特性的影響。因此，我們使用紫外光臭氧處理技術，以清除閘極絕緣層表面上經黃光製程定義源/汲極後可能殘留的有機污染；隨後再利用一自我組裝分子膜HMDS來改善閘極絕緣層的表面能，其改善後之表面能將適合有機主動層之薄膜成長。因閘極絕緣層的表面缺陷減少許多，與在其之上的有機主動層薄膜成長品質受到改善，而使有機薄膜電晶體的電特性大幅增加，其載子移動率可增加3個數量級之多。

In this thesis, we study on the device fabrication and electrical performance analysis and improvement of pentacene-based organic thin-film transistors (OTFTs) with bottom-contact (BC) structure. First, OTFTs with BC structure were fabricated with a fixed channel width and various channel lengths. It was found that the device performance deteriorated with the channel length, such as the carrier mobility decreased as the channel length decreased. This phenomenon is consistent with the discussion of the related reports; however, in the related reports, there was only qualitative description for this phenomenon, and no equation can quantitatively verify the experimental data or predict the trend of mobility with the channel length in the BC structure. Hence, we propose a mechanism, which is a modified formula, to present the channel length dependence on the field-effect mobility. In BC structure, the organic semiconductor active layer has worse growth quality near the edge of the source/drain (S/D) electrodes than that at middle region of channel. Therefore, the mobility near the S/D electrodes is much lower than that at middle region of channel. Furthermore, the mobility near the S/D electrodes has a greater weighting factor for the extracted overall mobility of device when the channel length becomes shorter, resulting in the decreased extracted overall mobility.
Second, because of the above-mentioned BC structure, the organic semiconductor layer has worse growth quality near the S/D electrodes, resulting in the low mobility region and the reduced carrier injection efficiency between metal and organic layer, which cause the increased contact resistance. When the channel length of OTFT device is decreased more, the electrical performance deteriorates further. Hence, we propose an alternative planar bottom-contact (pBC) structure to enhance the electrical performance of pentacene-based OTFTs. This pBC structure uses a bilayer dielectric to control planarization with a precise etch depth, and the planarization produces an optimum flatness near the S/D to improve the growth quality and continuity of pentacene. Because of the improved growth continuity of pentacene near the S/D, the contact resistance between the S/D and the pentacene was reduced significantly, thereby enhancing the electrical performance of OTFTs. In addition, reducing the channel length and improving the electrical performance for OTFTs are useful strategies for increasing the aperture ratio of pixels and high integration for active-matrix organic light-emitting displays (AMOLEDs). We introduced the pBC structure with bilayer dielectric to fabricate pentacene-based OTFTs with sub-micrometer channel length, and the pBC OTFTs had the high electrical performance that the conventional BC structure can't achieve.
The OTFTs with bottom-contact (BC) and bottom-gate structure have the organic active layer upon gate insulator; hence, the surface properties of gate insulator can affect the growth quality of organic layer. We used the UV/ozone cleaning to remove the organic contamination or residue that could be from the photolithography process for patterning S/D. After UV/ozone cleaning, we introduced a self-assembled monolayer (SAM), hexamethyldisilazane (HMDS), to improve the surface energy of gate insulator, which can be suitable for organic layer growth. Because the surface energy and the trap state density of the gate insulator were effectively improved, the combined scheme can significantly increase the performances of OTFTs, such that the mobility was dramatically increased by about three orders of magnitude.

Abstract (in Chinese) I
Abstract III
Acknowledgement (in Chinese) VI
Contents VII
List of Tables X
List of Figures XI
Chapter 1 Introduction 1
1.1 Overview of Organic Thin-Film Transistors 1
1.2 Organic Semiconductor Materials 2
1.2.1 Polymers 3
1.2.2 Small Molecules 3
1.3 Charge Carrier Transport in Organic Semiconductors 4
1.4 Device Structures and Operation of OTFTs 5
1.4.1 Device Structures of OTFTs 5
1.4.2 Operation of OTFTs 6
1.5 Motivation 8
1.6 Thesis Organization 9
Chapter 2 Device Fabrication and Electrical Parameters Extraction 19
2.1 Materials Selection 19
2.1.1 Substrate and Gate Electrode 19
2.1.2 Gate Insulator 20
2.1.3 Source and Drain Electrodes 20
2.1.4 Organic Semiconductor Layer 20
2.2 Device Fabrication Process 21
2.3 Measurement and Characterization for OTFTs 22
2.3.1 Electrical Measurement 22
2.3.2 Electrical Characterization 22
Chapter 3 Channel Length Dependence on the Field-Effect Mobility of OTFT 37
3.1 Introduction 37
3.2 Experiments 38
3.3 Results and Discussion 39
3.4 Conclusion 41
Chapter 4 Planar Bottom-Contact Structure for OTFT 46
4.1 Introduction 46
4.2 Experiments 48
4.3 Results and Discussion 49
4.4 Conclusion 53
Chapter 5 Planar Bottom-Contact Structure for Submicron OTFT Devices 58
5.1 Introduction 58
5.2 Experiments 59
5.3 Results and Discussion 60
5.4 Conclusion 65
Chapter 6 Combined Scheme of UV/Ozone and HMDS Treatment on Gate Insulator 75
6.1 Introduction 75
6.2 Experiments 76
6.3 Results and Discussion 77
6.4 Conclusion 82
Chapter 7 Conclusions and Future Works 91
7.1 Conclusions 91
7.2 Future Works 92
References 95

[1]J. E. Anthony, A. Facchetti, M. Heeney, S. R. Marder, and X. Zhan, “n-Type Organic Semiconductors in Organic Electronics,” Advanced Materials, Vol. 22, No. 34, pp. 3876－3892 (2010).
[2]C. L. Fan, Y. Z. Lin, and C. H. Huang, “Combined Scheme of UV/Ozone and HMDS Treatment on a Gate Insulator for Performance Improvement of a Low-Temperature-Processed Bottom-Contact OTFT,” Semiconductor Science and Technology, Vol. 26, No. 3, pp. 045006-1－045006-5 (2011).
[3]T. Sekitani, U. Zschieschang, H. Klauk, and T. Someya, “Flexible Organic Transistors and Circuits with Extreme Bending Stability,” Nature Materials, Vol. 9, No. 12, pp. 1015－1022 (2010).
[4]A. C. Mayer, M. T. Lloyd, D. J. Herman, T. G. Kasen, and G. G. Malliaras, “Postfabrication Annealing of Pentacene-Based Photovoltaic Cells,” Applied Physics Letters, Vol. 85, No. 25, pp. 6272－6274 (2004).
[5]C. C. Lee, C. H. Yuan, S. W. Liu, and Y. S. Shih, “Efficient Deep Blue Organic Light-Emitting Diodes Based on Wide Band Gap 4-Hydroxy-8-Methyl-1.5-Naphthyridine Aluminum Chelate as Emitting and Electron Transporting Layer,” Journal of Display Technology, Vol. 7, No. 8, pp. 454－458 (2011).
[6]C. D. Dimitrakopoulos, and P. R. L. Malenfant, “Organic Thin Film Transistors for Large Area Electronics,” Advanced Materials, Vol. 14, No. 2, pp. 99－117 (2002).
[7]A. Tsumura, K. Koezuka, and T. Ando, “Macromolecular Electronic Device: Field-Effect Transistor with a Polythiophene Thin Film,” Applied Physics Letters, Vol. 49, No. 18, pp. 1210–1212 (1986).
[8]G. Horowitz, D. Fichou, X. Z. Peng, Z. G. Xu, and F. Garnier, “A Field-Effect Transistor Based on Conjugated Alpha-Sexithienyl,” Solid State Communications, Vol. 72, No. 4, pp. 381–384 (1989).
[9]J. M. Shaw, and P. F. Seidler, “Organic Electronics: Introduction,” IBM Journal of Research and Development, Vol. 45, No. 1, pp. 3–9 (2001).
[10]C. D. Sheraw, L. Zhou, J. R. Huang, D. J. Gundlach, T. N. Jackson, M. G. Kane, I. G. Hill, M. S. Hammond, J. Campi, B. K. Greening, J. Francl, and J. West, “Organic Thin-Film Transistor-Driven Polymer-Dispersed Liquid Crystal Displays on Flexible Polymeric Substrates,” Applied Physics Letters, Vol. 80, No. 6, pp. 1088–1090 (2006).
[11]M. Mizukami, N. Hirohata, T. Iseki, K. Ohtawara, T. Tada, S. Yagyu, T. Abe, T. Suzuki, Y. Fujisaki, Y. Inoue, S. Tokito, and T. Kurita, “Flexible AM OLED Panel Driven by Bottom-Contact OTFTs,” IEEE Electron Device Letters, Vol. 27, No. 4, pp. 249–251 (2006).
[12]R. Wisnieff, “Display Technology: Printing Screens,” Nature, Vol. 394, No. 6690, pp. 225–227 (1998).
[13]R. Rotzoll, S. Mohapatra, V. Olariu, R. Wenz, M. Grigas, K. Dimmlerb, O. Shchekin, and A. Dodabalapur, “Radio Frequency Rectifiers Based on Organic Thin-Film Transistors,” Applied Physics Letters, Vol. 88, No. 12, pp. 123502–123502-3 (2006).
[14]T. Someya, T. Sekitani, S. Iba, Y. Kato, H. Kawaguchi, and T. Sakurai, “A Large-Area, Flexible Pressure Sensor Matrix with Organic Field-Effect Transistors for Artificial Skin Applications,” Proceedings of the National Academy of Sciences of the United States of America, Vol. 101, No. 27, pp. 9966–9970 (2004).
[15]G. Horowitz, “Organic Thin Film Transistors: From Theory to Real Devices,” Journal of Materials Research, Vol. 19, No. 7, pp. 1946–1962 (2004).
[16]S. K. Park, Y. H. Kim, J. I. Han, D. G. Moon, and W. K. Kim, “High-Performance Polymer TFTs Printed on a Plastic Substrate,” IEEE Transactions on Electron Devices, Vol. 49, No. 11, pp. 2008–2015 (2002).
[17]S. Locci, M. Morana, E. Orgiu, A. Bonfiglio, and P. Lugli, “Modeling of Short-Channel Effects in Organic Thin-Film Transistors,” IEEE Transactions on Electron Devices, Vol. 55, No. 10, pp. 2561–2567 (2008).
[18]B. Kumar, B. K. Kaushik, and Y. S. Negi, “Perspectives and Challenges for Organic Thin Film Transistors: Materials, Devices, Processes and Applications,” Journal of Materials Science: Materials in Electronics, Vol. 25, No. 1, pp. 1–30 (2014).
[19]B. C. Shekar, J. Lee, and S. W. Rhee, "Organic Thin Film Transistors: Materials, Processes and Devices," Korean Journal of Chemical Engineering, Vol. 21, No. 1, pp. 267–285 (2004).
[20]J. H. Schon, “New Phenomena in High Mobility Organic Semiconductors,” Physica Status Solidi (b), Vol. 226, No. 2, pp. 257–270 (2001).
[21]J. H. Schon, and B. Batlogg, “Trapping in Organic Field-Effect Transistors,” Journal of Applied Physics, Vol. 89, No. 1, pp. 336–342 (2001).
[22]G. Horowitz, “Organic Field-Effect Transistors,” Advanced Materials, Vol. 10, No. 5, pp. 365–377 (1998).
[23]T. Minari, T. Miyadera, K. Tsukagoshi, Y. Aoyagi, and H. Ito, “Charge Injection Process in Organic Field-Effect Transistors,” Applied Physics Letters, Vol. 91, No. 5, pp. 053508-1–053508-3 (2007).
[24]S. Schiefer, M. Huth, A. Dobrinevski, and B. Nickel, “Determination of the Crystal Structure of Substrate-Induced Pentacene Polymorphs in Fiber Structured Thin Films,” Journal of the American Chemical Society, Vol. 129, No. 34, pp. 10316–10317 (2007).
[25]J. R. Brews, K. K. Ng, and R. K. Watts, Submicron Integrated Circuits, John Wiley and Sons, NY, pp. 9–86 (1989).
[26]H. W. Zan, K. H. Yen, P. K. Liu, K. H. Ku, C. H. Chen, and J. Hwang, “Low-Voltage Organic Thin Film Transistors with Hydrophobic Aluminum Nitride Film as Gate Insulator,” Organic Electronics, Vol. 8, No. 4, pp. 450–454 (2007).
[27]A. Lodha and R. Singh, “Prospects of Manufacturing Organic Semiconductor-Based Integration Circuits,” IEEE Transactions on Semiconductor Manufacturing, Vol. 14, No. 3, pp. 281–296 (2001).
[28]K. Shibata, K. Ishikawa, H. Takezoe, H. Wada, and T Mori, “Contact Resistance of Dibenzotetrathiafulvalene-Based Organic Transistors with Metal and Organic Electrodes,” Applied Physics Letters, Vol. 92, No. 2, pp. 023305-1–023305-3 (2008).
[29]N. Takahashi, A. Maeda, K. Uno, E. Shikoh, Y. Yamamoto, H. Hori, Y. Kubozono, and A. Fujiwara, “Output Properties of C60 Field-Effect Transistors with Different Source/Drain Electrodes,” Applied Physics Letters, Vol. 90, No. 8, pp. 083503-1–083503-3 (2007).
[30]H. Klauk, G. Schmid, W. Radlik, W. Weber, L. Zhou, C. D. Sheraw, J. A. Nichols, and T. N. Jackson, “Contact Resistance in Organic Thin-Film Transistors,” Solid-State Electronics, Vol. 47, No. 2, pp. 297–301 (2003).
[31]J. Park, J. M. Kang, D. W. Kim, and J. S. Choi, “Contact Resistance Variation in Top-Contact Organic Thin-Film Transistors with the Deposition Rate of Au Source/Drain Electrodes,” Thin Solid Films, Vol. 518, No. 22, pp. 6232–6235 (2010).
[32]L. Zhou, S. Park, B. Bai, J. Sun, S. C. Wu, T. N. Jackson, S. Nelson, D. Freeman, and Y. Hong, “Pentacene TFT Driven AM OLED Displays,” IEEE Electron Devices Letters, Vol. 26, No. 9, pp. 640–642 (2005).
[33]C. L. Fan, P. C. Chiu, Y. H. Yang, and C. C. Lin, “Low-Temperature-Processed (< 100℃) Organic Thin-Film Transistor Using Hollow-Cathode CVD SiO2 as the Gate Insulator,” Semiconductor Science and Technology, Vol. 25, No. 7, pp. 075006-1–075006-5 (2010).
[34]H. S. Tan, T. Cahyadi, Z. B. Wang, A. Lohani, Z. Tsakadze, S.. Zhang, F. R. Zhu, and S. G. Mhaisalkar, “Low-Temperature-Processed Inorganic Gate Dielectrics for Plastic-Substrate-Based Organic Field-Effect Transistors,” IEEE Electron Devices Letters, Vol. 29, No. 7, pp. 6981–700 (2008).
[35]J. B. Koo, J. H. Lee, C. H. Ku, S. C. Lim, S. H. Kim, J. W. Lim, S. J. Yun, and T. Zyung, “The Effect of Channel Length on Turn-On Voltage in Pentacene-Based Thin Film Transistor,” Synthetic Metal, Vol. 156, No. 7-8, pp. 633–636 (2006).
[36]G. H. Gelinck, H. E. A. Huitema, E. van 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,” Nature Materials, Vol. 3, No. 2, pp. 106–110 (2004).
[37]I. Kymissis, C. D. Dimitrakopoulos, and S. Purushothaman, “High-Performance Bottom Electrode Organic Thin-Film Transistors,” IEEE Transactions on Electron Devices, Vol. 48, No. 6, pp. 1060–1064 (2001).
[38]D. Gupta, M. Katiyar, and D. Gupta, “An Analysis of The Difference in Behavior of Top and Bottom Contact Organic Thin Film Transistors Using Device Simulation,” Organic Electronics, Vol. 10, No. 5, pp. 775–784 (2009).
[39]S. J. Kang, M. Noh, D. S. Park, H. J. Kim, S. Y. Kim, B. W. Koo, I. N. Kang, and C. N. Whang, “Geometric Effect of Channel on Device Performance in Pentacene Thin-Film Transistor,” Japanese Journal of Applied Physics, Vol. 43, No. 11 A, pp. 7718–7721 (2004).
[40]N. Yoneya, M. Noda, N. Hirai, K. Nomoto, M. Wada, and J. Kasahara, “Reduction of Contact Resistance in Pentacene Thin-Film Transistors by Direct Carrier Injection into A-Few-Molecular-Layer Channel,” Applied Physics Letters, Vol. 85, No. 20, pp. 4663–4665 (2004).
[41]M. Leufgen, U. Bass, T. Muck, T. Borzenko, G. Schmidt, J. Geurts, V. Wagner, and L. W. Molenkamp, "Optimized Sub-Micron Organic Thin-Film Transistors: The Influence of Contacts and Oxide Thickness," Synthetic Metals, Vol. 146, No. 3, pp. 341–345 (2004).
[42]K. D. Jung, Y. C. Kim, H. Shin, B. G. Park, J. D. Lee, E. S. Cho, and S. J. Kwon, “A Study on the Carrier Injection Mechanism of The Bottom-Contact Pentacene Thin Film Transistor,” Applied Physics Letters, Vol. 96, No. 10, pp. 103305-1–103305-3 (2010).
[43]C. L. Fan, T. H. Yang, and P. C. Chiu, “Performance Improvement of Bottom-Contact Pentacene-Based Organic Thin-Film Transistors by Inserting a Thin Polytetrafluoroethylene Buffer Layer,” Applied Physics Letters, Vol. 97, No. 14, pp. 143306-1–143306-3 (2010).
[44]M. Xu, M. Nakamura, M. Sakai, and K. Kudo, “High-Performance Bottom-Contact Organic Thin-Film Transistors with Controlled Molecule-Crystal/Electrode Interface,” Advanced Materials, Vol. 19, No. 3, pp. 371–375 (2007).
[45]M. Xu, M. Nakamura, and K. Kudo, “Thickness Dependence of Mobility of Pentacene Planar Bottom-Contact Organic Thin-Film Transistors,” Thin Solid Films, Vol. 516, No. 9, pp. 2776–2778 (2008).
[46]J. Park, R. D. Yang, C. N. Colesniuc, A. Sharoni, S. Jin, I. K. Schuller, W. C. Trogler, and A. C. Kummel, “Bilayer Processing for an Enhanced Organic-Electrode Contact in Ultrathin Bottom Contact Organic Transistors,” Applied Physics Letters, Vol. 92, No. 19, pp. 193311-1–193311-3 (2008).
[47]S. C. Lim, S. H. Kim, J. H. Lee, M. K. Kim, D. J. Kim, and T. Zyung, “Surface-Treatment Effects on Organic Thin-Film Transistors,” Synthetic Metals, Vol. 148, No. 1, pp. 75–79 (2005).
[48]A. Benor, and D. Knipp, “Contact Effects in Organic Thin Film Transistors with Printed Electrodes,” Organic Electronics, Vol. 9, No. 2, pp. 209–219 (2008).
[49]P. V. Necliudov, M. S. Shur, D. J. Gundlach, and T. N. Jackson, “Contact Resistance Extraction in Pentacene Thin Film Transistors,” Solid-State Electronics, Vol. 47, No. 2, pp. 259–262 (2003).
[50]X. Yan, U. Wang, H. Wang, H. Wang, and D. Yan, “Improved n-Type Organic Transistors by Introducing Organic Heterojunction Buffer Layer under Source/Drain Electrodes,” Applied Physics Letters, Vol. 89, No. 5, pp. 053510-1–053510-3 (2006).
[51]C. R. Newman, C. D. Frisbie, D. A. Da Silva Filho, J. L. Bredas, P. C. Ewbank, and K. R. Mann, “Introduction to Organic Thin Film Transistors and Design of n-Channel Organic Semiconductors,” Chemistry of Materials, Vol. 16, No. 23, pp. 4436–4451 (2004).
[52]B. Stadlober, U. Haas, H. Gold, A. Haase, G. Jakopic, G. Leising, N. Koch, S. Rentenberger, and E. Zojer, “Orders-of-Magnitude Reduction of the Contact Resistance in Short-Channel Hot Embossed Organic Thin Film Transistors by Oxidative Treatment of Au-Electrodes,” Advanced Functional Materials, Vol. 17, No. 15, pp. 2687–2692 (2007).
[53]C. L. Fan, P. C. Chiu, Y. Z. Lin, T. H. Yang, and C. Y. Chiang, “Investigation on the Electrical Characteristics of a Pentacene Thin-Film Transistor and Its Reliability under Positive Drain Bias Stress,” Semiconductor Science and Technology, Vol. 26, No. 23, pp. 125007-1–125007-6 (2011).
[54]C. Auner, U. Palfinger, H. Gold, J. Kraxner, A. Haase, T. Haber, M. Sezen, W. Grogger, G. Jakopic, J. R. Krenn, G. Leising, and B. Stadlober, “Residue-Free Room Temperature UV-Nanoimprinting of Submicron Organic Thin Film Transistors,” Organic Electronics, Vol. 10, No. 8, pp. 1466–1472 (2009).
[55]B. Crone, A. Dodabalapur, Y.Y. Lin, R.W. Filas, Z. Bao, A. LaDuca, R. Sarpeshkar, H.E. Katz, and W. Li, “Large-Scale Complementary Integrated Circuits Based on Organic Transistors,” Nature, Vol. 403, No. 6769,pp. 521–523 (2000).
[56]J. Z. Wang, Z. H. Zheng, and H. Sirringhaus, “Suppression of Short-Channel Effects in Organic Thin-Film Transistors,” Applied Physics Letters, Vol. 89, No. 8, pp. 083513-1–083513-3 (2006).
[57]L. Wang, D. Fine, T. Jung, D. Basu, H. Von Seggern, and A. Dodabalapur, “Pentacene Field-Effect Transistors with Sub-10-nm Channel Lengths,” Applied Physics Letters, Vol. 85, No. 10, pp. 1772–1774 (2004).
[58]K. Tukagoshi, F. Fujimori, T. Minari, T. Miyadera, T. Hamano, and Y. Aoyagi, “Suppression of Short Channel Effect in Organic Thin Film Transistors,” Applied Physics Letters, Vol. 91, No. 11, pp. 113508-1–113508-3 (2007).
[59]Y. Ishii, H. Sakai, and H. Murata, “Fabrication of a Submicron-Channel Organic Field-Effect Transistor Using A Controllable Electrospun Single Fibre as a Shadow Mask,” Nanotechnology, Vol. 22, No. 20, pp. 205202-1–205202-6 (2011).
[60]B. K. Sarker, and S. I. Khondaker, “High-Performance Short Channel Organic Transistors Using Densely Aligned Carbon Nanotube Array Electrodes,” Applied Physics Letters, Vol. 100, No. 2, pp. 023301-1–023301-4 (2012).
[61]C. L. Fan, Y. Z. Lin, W. D. Lee, S. J. Wang, and C. H. Huang, “Improved Pentacene Growth Continuity for Enhancing the Performance of Pentacene-Based Organic thin-Film Transistors,” Organic Electronics, Vol. 13, No. 12, pp. 2924–2928 (2012).
[62]J. B. Lee, P. C. Chang, J. A. Liddle, and V. subramanian, “10-nm Channel Length Pentacene Transistors,” IEEE Transactions on Electron Devices, Vol. 52, No. 9, pp. 1874–1879 (2005).
[63]D. J. Gundlach, L. Zhou, J. A. Nichols, T. N. Jackson, P. V. Necliudov, and M. S. Shur, “An Experimental Study of Contact Effects in Organic Thin Film Transistors,” Journal of Applied Physics, Vol. 100, No. 2, pp. 024509-1–024509-13 (2006).
[64]C. L. Fan, C. C. Lin, T. H. Yang, and C. H. Huang, “N2O-Plasma Effect on Low-Temperature Deposited Gate Dielectric for Organic Thin-Film Transistors,” Electronics Letters, Vol. 44, No. 19, pp. 1158-1–1158-2 (2008).
[65]A. D. Carlo, F. Piacenza, A. Bolognesi, B. Stadlober, and H. Maresch, “Influence of Grain Sizes on the Mobility of Organic Thin-Film Transistors,” Applied Physics Letters, Vol. 86, No. 26, pp. 263501-1–263501-3 (2005).
[66]C. L. Fan, T. H. Yang, P. C. Chiu, C. H. Huang, and C. I. Lin, “Organic Thin-Film Transistor Performance Improvement Using Ammonia (NH3) Plasma Treatment on the Gate Insulator Surface,” Solid-State Electronics, Vol. 53, No. 2, pp. 246–250 (2009).
[67]B. T. Wu, T. K. Su, M. L. Tu, A. C. Wang, T. S. Chen, T. Z. Chiou, Y. T. Chiou, and C. H. Chu, “Interface Modification in Organic Thin Film Transistors,” Japanese Journal of Applied Physics, Vol. 44, No. 4S, pp. 2783–2786 (2005).
[68]S. K. Kang, J. Y. Park, S. M. Jung, H. J. Lee, P. K. Son, J. C. Kim, T. H. Yoon, and M. S. Yi, “Performance Enhancement of Organic Thin-Film Transistors by Low-Energy Argon Ion Beam Treatment of Gate Dielectric Surface,” Japanese Journal of Applied Physics, Vol. 46, No. 4B, pp. 2696–2699 (2007).
[69]Y. S. Jang, J. H. Cho, D. H. Kim, Y. D. Park, M. K. Hwang, and K. W. Cho, “Effects of the Permanent Dipoles of Self-Assembled Monolayer-Treated Insulator Surfaces on the Field-Effect Mobility of a Pentacene Thin-Film Transistor,” Applied Physics Letters, Vol. 90, No. 13, pp. 132104-1–132104-3 (2007).
[70]D. Guo, S. Entani, S. Ikeda, and K. Saiki, “Effect of UV/ozone Treatment of the Dielectric Layer on the Device Performance of Pentacene Thin Film Transistors,” Chemical Physics Letters, Vol. 429, No. 1-3, pp. 124–128 (2006).
[71]M. Susukida, M. Kamei, H. Takezoe, and K. Ishikawa, “Usefulness of Substrate Cleaning with Carbon Dioxide for Organic Electronic Devices,” Japanese Journal of Applied Physics, Vol. 46, No. 36-40, pp. L910–L912 (2007).
[72]J. B. Koo, S. Y. Kang, I. K. You, and K. S. Suh, “Effect of UV/ozone Treatment on Hysteresis of Pentacene Thin-Film Transistor with Polymer Gate Dielectric,” Solid-State Electronics, Vol. 53, No. 6, pp. 621–625 (2009).
[73]A. Wang, I. Kymissis, V. Bulović, and A. I. Akinwande, “Tunable Threshold Voltage and Flatband Voltage in Pentacene Field Effect Transistors,” Applied Physics Letters, Vol. 89, No. 11, pp. 112109-1–112109-3 (2006).
[74]H. Ohnuki, W. Changhai, M. Izumi, T. Tatewaki, and K. Ikegami, “Effects of Interfacial Modification on the Performance of an Organic Transistor Based on TCNQ LB Films,” Thin Solid Films, Vol. 516, No. 9, pp. 2747–2752 (2008).
[75]W. Y. Chou, C. W. Kuo, H. L. Cheng, Y. R. Chen, F. C. Tang, F. Y. Yang, D. Y. Shu, and C. C. Liao, “Effect of Surface Free Energy in Gate Dielectric in Pentacene Thin-Film Transistors,” Applied Physics Letters, Vol. 89, No. 11, pp. 112126-1–112126-3 (2006).
[76]I. Yagi, K. Tsukagoshi, and Y. Aoyagi, “Modification of the Electric Conduction at the Pentacene/SiO2 Interface by Surface Termination of SiO2,” Applied Physics Letters, Vol. 86, No. 10, pp. 103502-1–103502-3 (2005).
[77]M. Yoshida, S. Uemura, T. Kodzasa, T. Kamata, M. Matsuzawa, and T. Kawai, “Surface Potential Control of an Insulator Layer for the High Performance Organic FET,” Synthetic Metals, Vol. 137, No. 1-3, pp. 967–968 (2003).
[78]J. B. Koo, S. H. Kim, J. H. Lee, C. H. Ku, S. C. Lim, and T. Zyung, “The Effects of Surface Treatment on Device Performance in Pentacene-Based Thin Film Transistor,” Synthetic Metals, Vol. 156, No. 2-4, pp. 99–103 (2006).
[79]C. R. Newman, C. D. Frisbie, D. A. Da Silva Filho, J. L. Bredas, P. C. Ewbank, and K. R. Mann, “Introduction to Organic Thin Film Transistors and Design of n-Channel Organic Semiconductors,” Chemistry of Materials, Vol. 16, No. 23, pp. 4436–4451 (2004).
[80]E. V. Jelenkovic, and K. Y. Tong, “Stability of Nitrided Silicon Dioxide Deposited by Reactive Sputtering,” Applied Physics Letters, Vol. 67, No. 18, pp. 2693–2695 (1995).
[81]K. Sekine, Y. Saito, M. Hirayama, and T. Ohmi, “Highly Reliable Ultrathin Silicon Oxide Film Formation at Low Temperature by Oxygen Radical Generated in High-Density Krypton Plasma,” IEEE Transactions on Electron Devices, Vol. 48, No. 8, pp. 1550–1555 (2001).
[82]L. L. Chua, J. Zaumseil, J. F. Chang, E. C. W. Ou, P. K. H. Ho, H. Sirringhaus, and R. H. Friend, “General Observation of n-Type Field-Effect Behaviour in Organic Semiconductors,” Nature, Vol. 434, No. 7030, pp. 194–199 (2005).
[83]S. K. Park, T. N. Jackson, J. E. Anthony, and D. A. Mourey, “High Mobility Solution Processed 6, 13-Bis(Triisopropyl-Silylethynyl) Pentacene Organic Thin Film Transistors,” Applied Physics Letters, Vol. 91, No. 6, pp. 063514-1–063514-3 (2007).
[84]J. S. Park, W. S. Jeon, J. S. Park, J. H. Kwon, and M. C. Suh, “The Effect of Surface Treatment of Bottom Contact Organic Thin Film Transistor,” Synthetic Metals, Vol. 161, No. 17-18, pp. 1953–1957 (2011).
[85]C. C. Li, “Investigation of Top-Contact Organic Thin-Film Transistor with New Patterning Active Layer by Traditional Photolithography,” Masters Dissertation, National Taiwan University of Science and Technology, Taipei, Taiwan (2013).
[86]H. S. Chang, “Investigation on Performance Improvement of Organic Thin-Film Transistor Using p-Type Doped Injection Layer,” Masters Dissertation, National Taiwan University of Science and Technology, Taipei, Taiwan (2013).