在本論文中，我們提出一個新穎的非晶矽薄膜電晶體製作技術。我們在Light-shield結構的主動區側璧多沉積了一層高摻雜的非晶矽(N+ a-Si:H)的側璧空間層. 對於這個新結構薄膜電晶的製程步驟跟我們的現在常用於液晶面板的薄膜電晶體是幾乎相同的，而他的光罩數目也沒有增加甚至於改變。所以這個製作技術可以適用於現今面板廠線上的製程。由於新結構薄膜電晶的側璧空間層可以減少我們的主動層合我的源極/汲極金屬的接觸，減少蕭基接觸所產生的漏電。此外由於非晶矽是光敏感的材料，對於必需操作在被光模組的上方驅動液晶的薄膜電晶體會使之產生漏電因而影響到我們液晶的驅動。而我提出的薄膜電晶體結構如同light-shield結構他不但具有抵擋光漏電的能力也沒有light-shield結構中因為消基接觸產生的漏電。由於我們提出的新結構在主動層側璧多的一層高摻雜的非晶矽層，降低了我們電晶體的串聯電阻也因此大大的提升我們電流遷移率(1.05 cm2/Vsec)，於是我們可以就由這樣的製程改變壤我們的元件可以有效的改善漏電流與驅動能力，提升元件的特性使之可以應用於驅動大面板、高解析度面板和有機發光二極體面板。

In this thesis, novel technology for manufacturing high-performance hydrogenated amorphous silicon (a-Si:H) TFT is developed . In the bottom gate light-shied a-Si:H TFT structure, the side edge of a-Si:H island is capped with extra deposition of heavily phosphorous-doped a-Si layer. The new structure a-Si:H TFT process steps is almost unchanged. The masksteops of fabrication new structure TFT are the same as the inverter-staggered TFT. Such an ingenuity can effectively eliminate the leakage path between the parasitic contacts between source/drain metal and a-Si:H at the edge of a-Si:H island. a-Si:H is a well-known photosensitivity material. For driving LCD the TFT must be operated with illuminated environment. It will cause the leakage current. The new TFT structure is similar to the light-shield TFT proposed by Akiyama in 1989. So the new structure TFT can not only reduce the schoktty emission leakage current but also the photo-leakage current. In addition, electrical performance of the novel a-Si:H TFT device exhibits superior effective carrier mobility, as high as 1.05 cm2/Vsec due to the enormous improvement in parasitic resistance. The impressively high performance provides the potential of our proposed a-Si:H TFT to apply for AMLCD and AMOLED technology.

Chapter 1 Introduction
1.1 General Background………………1
1.2 Motivation ………………………..3
1.3 Organization of This Thesis………5

Chapter 2 Physics and Structure of a-Si:H TFT
2.1 The physics of amorphous thin film transistors…………………………6
2.2 Photosensitivity of a-Si:H…………8
2.3 a-Si:H TFT structure and Processing Steps……………………………..9
2.3.1 a-Si:H structure……………………9
2.3.2 New structure processing steps…...11
2.4 Summary……………………….....13

Chapter 3 Conductance improvement and stability enhance of New structure a-Si:H TFT
3.1 Introduction of a-Si:H TFT performance…..........................................14
3.2 TFT conductance improvement……..15
3.3 TFT stability enhancement………….19
3.4 Leakage current improvement………20

Chapter 4 Conclusions
4.1 Conclusions………………………….22

Reference
Chapter 1
[1-1] Yue Kuo .Thin Film Transistors. Vol 1 . pp 3-5.
[1-2] Jan Blochwitz Nimoth, Julia Brandt, Michael Hofmann, and Jan Birnstock, Martin Pfeiffer, Gufeng He, Philipp Wellmann, and Karl Leo, Full Color Active Matrix OLED Displays with High Aperture Ratio, SID 2004
[1-3] Takatoshi Tsujimura*, Yoshinao Kobayashi e.t.c. A 20-inch OLED Display Driven by Super-Amorphous-Silicon Technology. SID 2003.
[1-4] M. Akiyama, H. Toeda, H. Ohtaguro, K. Suzuki, and H. Ito, “An a-Si TFT with A New Light-Shield Structure and Its Application to Active-Matrix Liquid Crystal Displays”, in IEDM Tech. Dig., Dec 1988, pp 268-271.








Chapter 2
[2-1] M. J. Powell. B. C. Easton, and D. H. Nicholls. “Annealing and light induced changes in the field effect conductance of amorphous silicon,” J. Appl. Phys., vol. 53, pp. 5068-5078, 1982.
[2-2] M. Shur and M. Hack, “Physics of amorphous silicon based alloy field- effect transistors,” J. Appl. Phys., vol. 53, pp. 3831-3842. 1984.
[2-3] MARTIN J. POWELL. The Physics of Amorphous-Silicon Thin-Film Transistors. IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 36. NO. 12. DECEMBER 1989
[2-5] C. van Berkel and M. J. Powell, “Photo-field effect in amorphous silicon thin film transistors,” J. Appl. Phps., vol. 60, pp. 1521-1527. 1986.
[2-6]Yue Kuo, Thin Film Transistors, Vol 1, pp 184-239.







Chapter 3
[3-1]. H. Yamamoto, H. Matsumaru, K. Shirahashi, M. Nakatani, A. Sasano, N. Konishi, K. Tsutsui, and T. Tsukada, IEDM Tech. Dig.,851 (1990)
[3-2] G. Kawachi, E. Kimura, Y. Wakui, N. Konishi, H. Yamamoto, Y. Matsukawa, and A. Sasano, IEEE Trans. Elec. Devices., 41, 1120(1994).
[3-3] D.B. Thomason, T.N. Jackson, IEEE ELECTRON DEVICE LETTERS, 18,8(1997).
[3-4] D.B. Thomason, T.N. Jackson, IEEE ELECTRON DEVICE LETTERS, 19, 4(1998).
[3-5]G. Kawachi, E. Kimura, Y. Wakui, N. Konishi, H. Yamamoto, Y. Matsukawa, A. Sasano, Electron Devices, IEEE Transactions on ., 41, 7(1994)
[3-6] R.M.A. Dawson , M.G. Kane, SID Tech. Dig., 372(2001)
[3-7] J.A. Nichols, T.N. Jackson, M.H. Lu and M. Hack, SID Tech. Dig.,1368(2002)
[3-8]T. Tsujimura, Y. Kobayashi, K. Murayama, A. Tanaka, M. Morooka, E. Fukumoto, H. Fujimoto, J. Sekine, K. Kanoh, K. Takeda, K. Miwa, M. Asano, N. Ikeda, S. Kohara, and S. Ono, SID Tech. Dig.,6(2003)
[3-9]Y. He, R. Hattori, J. Kanicki, IEEE TRANSACTIONS ON ELECTRON DEVICE, 48, 7(2001).
[2.10] A. Nathan, D. Striakhilev, .Pervati, .K. akariya,.A.Kumar, K. S. Karim, A. Sazonov, Materials and Devices Technology as held at the 2003 MRS Spring Meeting.; 29(2003)
[3-11] J. H. Lee, B.H. You, W.J. Nam, H.J. Lee, M.K. Han, SID Tech. Dig.,264(2004).
[3-12] J. J. Lih, and C.F. Sung, Journal of the Society for Information Display., 11, 617(2003)
[3-13]B. Popescu, M. Hundhausen, and L. Ley, Journal of Non-Crystalline Solids., 283,155(2001)
[3-14] J. Kanicki, F. R. Libsch, J. Griffith, and R. Polastre, Journal of Applied Physics., 69, 2339(1991)
[3-15] S. M. Sze, Physics of Semiconductor Devices, p. 402, Wiley, New York (1981)
[3-16] S. Luana, G.W. Neudeck, Journal of Applied Physics., 72, 766(1992).
[3-17] C.Y. Chen, J. Kanicki, Solid-State Electronics., 42, 705(1998)