本實驗搭配低氫含量的氧化矽於Indium Gallium Zinc Oxide (IGZO)薄膜電晶體，已被証實有良好的薄膜電晶體特性由X-ray繞射量測分析可知，本研究中所使用的所有製程參數都會使得IGZO薄膜呈現非晶相的一個晶格結構，為較佳的IGZO薄膜結構。除此之外，也會使得IGZO薄膜在可見光範圍內，平均透光率都能達80%以上，能夠滿足透明電晶體的一個標準需求。而經由能量散射光譜分析分析，IGZO薄膜初期氧含量比例66.23%，製程中以低氫含量的氧化矽與IGZO薄膜搭配，主要減少在製程中氫原子與IGZO薄膜裡氧原子產生置換，避免IGZO薄膜特性由半導體變成導體，元件完成後再驗證IGZO氧含量比例58.1%，確認低氫含量氧化矽對於IGZO氧含量影響是將可以被降到最低的。
此外，透過原子力顯微鏡量測分析，可以得知低氫含量的氧化矽薄膜表面平整，其表面粗糙度Rrms值 1.52 nm，適合IGZO薄膜的成長，驗證了IGZO於低氫含量的氧化矽薄膜上的高載子傳輸特性。其元件的具有相當高的場效載子遷移率(13.75 cm2/Vs)、低臨界電壓(0.125 V)，期待未來能將其應用到AMOLED的相關元件上。

Amorphous IGZO-based thin film transistors(TFTs) with a low hydrogen content silicon oxide (SiOx) as gate insulator layer are demonstrated. The IGZO film processed in this study are amorphous crystalline revealed by X-ray diffraction measurements and exhibit over 80% of transparency in the visible light range. During the deposition process of insulator such as SiOx or SiNx, the oxygen of IGZO thin film will be substituted by the high content of hydrogen, leading to the transformation of IGZO thin film from semiconductor to conductor. To prevent hydrogen in substitution for oxygen, low hydrogen content silicon oxide was applied in IGZO thin film transistor. From EDS analysis, the original oxygen content of IGZO thin film was measured to be 66.23%. After low hydrogen content silicon oxide deposition process, 58.1% of oxygen is remained in IGZO thin film. This proves that low hydrogen content silicon oxide has the minimum impact on the oxygen content of IGZO.
The smooth surface (1.52nm) of IGZO thin film confirmed by AFM measurement could facilitate IGZO thin film deposition, leading to the high mobility (13.75 cm2/Vs), low threshold voltage (0.125V). It is expected that the presented device could be applied to AMOLED related device in the future.

[1] K. Nomura, H. Ohta, K. Ueda, T. Kamiya, M. Hirano and H. Hosono, “Thin-Film Transistor Fabricated in Single-Crystalline Transparent Oxide Semiconductor,” Science., vol. 300, pp. 1269, 2003.
[2] K. Nomura1, H. Ohta, A. Takagi, T. Kamiya, M. Hirano and H. Hosono,“Room-temperature fabrication of transparent flexible thin-film transistors using amorphous oxide semiconductors,” Nature., vol. 432, pp. 488, 2004.
[3] T. Kamiya, K. Nomura and H. Hosono, “Present status of amorphous In–Ga–Zn–O thin-film transistors,” Science and Technology of Advanced Materials., vol. 11, pp. 044305, 2010.
[4] Z. Ji, J. Du, J. Fan, W. Wang, “Gallium oxide films for filter and solar-blind UV detector,” Optical Materials., vol. 28, pp. 415–417, 2006.
[5] R. B. H. Tahar, T. Ban, Y. Ohya, Y. Takahashi, “Optical, structural, and electrical properties of indium oxide thin films prepared by the sol-gel method,” Journal of Applied Physics., vol. 82, pp. 865, 1997.
[6] R. Navamathavana, C. K. Choia, S. J. Park, “Electrical properties of ZnO-based bottom-gate thin film transistors fabricated by using radio frequency magnetron sputtering,” Journal of Alloys and Compounds., vol. 475, pp. 889-892, 2009.
[7] G. Gordillo, C. Calderon, “Properties of ZnO thin films prepared by reactive evaporation,” Solar Energy Mater and Solar Cells., vol. 69, pp. 251–260, 2001.
[8] T. Kamiya, Y. Takeda, K. Nomura, H. Ohta, H. Yanagi, M. Hirano, H. Hosono, “Self-Adjusted, Three-Dimensional Lattice-Matched Buffer Layer for Growing ZnO Epitaxial Film: Homologous Series Layered Oxide, InGaO3(ZnO)5,” Crystal Growth and Design., vol. 6, pp. 2451-2456, 2006.
[9] H. Hosono, “Transparent Amorphous Oxide Semiconductors (TAOS) for High Performance TFTs,” Symposium Digest of Technical Papers., vol. 38, Issue 1, pp. 1830-1833, 2007.
[10] H. Hosono, “Ionic amorphous oxide semiconductors: Material design, carrier transport, and device application, ” Journal of Non-Crystalline Solids., vol. 352, pp. 851-858, 2006.
[11] J. Robertson, “Disorder, band offsets and dupability of transparent conducting oxides,” Thin Solid Films., vol. 516, pp. 1419-1425, 2008.
[12] K. Nomura, A. Takagi, T. Kamiya, H. Ohya, M. Hirano, H. Hosono, “Amorphous Oxide Semiconductor Towards High-Performance Flexible Thin-Film Transistors,” Japanese Journal of Applied Physics., vol. 45, pp. 4303-4308, 2006.
[13] S. M. Sze, “Semiconductor Devices-Physics and Technology,” John Wiley & Sons, 1985.
[14] A. Sato, K. Abe, R. Hayashi1, H. Kumomi, K. Nomura, T. Kamiya, M. Hirano, H.Hosono, “Amorphous In–Ga–Zn–O coplanar homojunction thin-film transistor, ”Applied Physics Letters., vol. 94, pp. 133502, 2009.
[15] T. Gao, Y. Masuda, K. Koumoto, “Band Gap Energy of SrTiO3 Thin Film Prepared by the Liquid Phase Deposition Method,” Journal of the Korean Ceramic Society., vol. 40, pp. 213-218, 2003.
[16] L. L. Jiang, X. G. Tang, S. J. Kuang, and H. F. Xiong, “Surface chemical states of barium zirconate titanate thin films prepared by chemical solution deposition,” Appl. Surf. Sci., vol. 255, pp. 8913, 2009.
[17] M. Orita, M. Takeuchi, H. Sakai, H. Tanji, “New Transparent Conductive Oxides with YbFe2O4 Structure,” Japanese Journal of Applied Physics., vol. 34, Issue 11B, pp. L1550-L1552, 1995.
[18] M. Nespolo, A. Sato, T. Osawa and H. Ohashi, “Crystal Research and Technology,” vol. 35, Issue 2, pp. 151-165, 2000.
[19] G. B. Gonzalez, J. B. Cohen, J. H. Hwang, T. O. Mason, J. P. Hodges and J. D. Jorgensen, “Neutron diffraction study on the defect structure of indium–tin–oxide,” Journal of Applied Physics., vol. 89, pp. 2550-2555, 2001.
[20] J. Lee, J. S. Park, Y. S. Pyo, D. B. Lee, E. H. Kim, D. Stryakhilev, T. W. Kim, D. U. Jin and Y. G. Mo, “The influence of the gate dielectrics on threshold voltage instability in amorphous indium-gallium-zinc oxide thin film transistors,” Applied Physics Letters., vol. 95, pp. 123502, 2009.
[21] B. S. Jeong, C. M. Park, M. G. Kim, H. J.Chung, T. K. Ahn, S. K Heo, J. H. Jeong, M. K. Kim, H. H. Park, J. M. Huh, Y. G. Mo, H. D. Kim and S. S. Kim, “Effect of Passivation Layer Properties on the Performance of Oxide TFTs,” IMID Symposium Digest., pp. 1040-1043, 2009.
[22] C. Y. Tseng, C. Y. Su, S. L. Lin, G. R. Hu, M. C. Wei, M. F. Chiang and W. L. Liau, “6 inch EPD with a-IGZO TFT on the PEN substrate,” IDMC’11., ps-053, 2011.
[23] Y. J. Chung, J. H. Kim, U. K. Kim, D. Y. Cho, H. S. Jung, J. K. Jeong and C. S. Hwang, “Direct Observation of Hole Current in Amorphous Oxide Semiconductors under Illumination,” Electrochemical and Solid-State Letters., vol. 14, pp. G35-G37, 2011.
[24] J. H. Kim, U. K. Kim, Y. J. Chung, J.S. Jung and S. H. Ra, “ The effects of device geometry on the negative bias temperature instability of Hf-In-Zn-O thin film transistors under light illumination,” Applied Physics Letters., vol. 98, pp. 023507, 2011.
[25] J. Song, H. C. Oh, T. J. Park, C. S. Hwang, S. H. K. Park, S. M. Yoon and C. S. Hwang, “Properties of MIS Capacitors Using the Atomic-Layer-Deposited ZnO Semiconductor and Al2O3 Insulator,” Journal of The Electrochemical Society., vol. 155, pp. H858-H863, 2008.
[26] C. T. Tsai, T. C. Chang, S. C. Chen, I. Lo, S. W. Tsao, M. C. Hung, J. J. Chang, C. Y. Wu and C. Y. Huang, “Influence of positive bias stress on N2O plasma improved InGaZnO thin film transistor,” Applied Physics Letters., vol. 96, pp. 242105, 2010.
[27] H. H. Lu, H. C. Ting, T. H. Shih, C. Y. Chen, C. S. Chuang and Y. Lin, “32-inch LCD Panel Using Amorphous Indium-Gallium-Zinc-Oxide TFTs,” SID Symposium Digest., vol. 41, Issue 1, pp. 1136-1138, 2010.
[28] J. S. Lee, S. Chang, S. M. Koo and S. Y. Lee, “High-Performance a-IGZO TFT With ZrO2 Gate Dielectric Fabricated at Room Temperature,” IEEE Electron Device Letters., vol. 31, Issue 3, pp. 225-227, 2010.
[29] M. Kim, J. H. Jeong, H. J. Lee, T. K. Ahn, H. S. Shin, J. S. Park, J. K. Jeong, Y. G. Mo and H. D. Kim, “High mobility bottom gate InGaZnO thin film transistors with SiOx etch stopper,” Applied Physics Letters., vol. 90, pp. 212114, 2007.
[30] C. Y. Lin , Y. H. Yeha, C. C. Cheng, C. M. Lai, M. J. Yu , S. E. Liu , G. T. Ho , H. T. Lin and C. C. Wu, “2.2-inch QQVGA AMOLED driven by low temperature top-gate a-IGZO TFT,” IEEE Photonics Society., pp. 307-308, 2010.
[31] R. I. Kondratyuk, K. Im, D. Stryakhilev, C. G. Choi, M. G. Kim, H. Yang, H. Park, Y. G. Mo, H. D. Kim and S. S. Kim, “A Study of Parasitic Series Resistance Components in In–Ga–Zn–Oxide (a-IGZO) Thin-Film Transistors,” IEEE Electron Device Letters., vol. 32, issue 4, pp. 503-505, 2011.
[32] T. C. Fung, K. Abe, H. Kumomi and J. Kanicki, “ Electrical Instability of RF Sputter Amorphous In-Ga-Zn-O Thin-Film Transistors,” Journal of Display Technology., vol. 5, Issue 12, pp. 452-461,2009.
[33] T. Arai, N. Morosawa, K. Tokunaga, Y. Terai, E. Fukumoto, T. Fujimori, T. Nakayama, T. Yamaguchi and T. Sasaoka, “Highly Reliable Oxide-Semiconductor TFT for AM-OLED Display,” SID Symposium Digest., vol. 41, Issue 1, pp. 1033-1036, 2010.
[34] N. Morosawa, Y. Ohshima, M. Morooka, T. Arai and T. Sasaoka, “A Novel Self-Aligned Top-Gate Oxide TFT for AM-OLED Displays,” SID Symposium Digest of Technical Papers., vol. 42, Issue 1, pp. 479-482,2011.
[35] A. Sato, K. Abe, R. Hayashi, H. Kumomi, K. Nomura, T. Kamiya, M. Hirano and H. Hosono, “Amorphous In–Ga–Zn–O coplanar homojunction thin-film transistor,” Applied Physics Letters., vol. 94, pp. 133502, 2009.
[36] Dae-ho Son, Dae-Hwan Kim*, Shi-Joon Sung, Eun-Ae Jung, Jin-Kyu Kang, “High performance and the low voltage operating InGaZnO thin film transistor,” Current Applied Physics., vol 10, Issue 4, pp. e157–e160, 2010.