由於金屬氧化物薄膜電晶體獨特的製程特質及材料特性，使它們在新興的薄膜電晶體應用上成為最具有競爭性的選擇，包含均勻性好可以應用在大尺寸的面板、低溫製程而應用於可撓式的結構以及低成本製作等特殊需求的產品上。為了滿足下一世代的顯示器，TFT的載子遷移率需要更高，所以本論文將搭配高介電常數(High-k)料二氧化鉿(HfO2)來製備元件之閘極絕緣層(Gate Insulator)，並使用氧化鋅鋅錫來當作主動層，因為氧化銦鋅錫具有比氧化銦鎵鋅更高的載子遷移率，但是氧化銦鋅錫其材料特性較不穩定，所以本論文將透過高溫爐管退火，提升元件特性及穩定性，並探討以高溫爐管退火對於元件之影響。
首先，本論文將新購置的高溫爐管進行溫度及均勻度測試，以確定實驗環境參數是否一致，接下來利用金屬遮罩(Shadow Mask)製作TFT元件，分別透過溫度、環境及時間的調變，找出擁有最佳元件電特性之退火環境參數，並透過元件穩定性的測試，探討在持續施加偏壓時的劣化機制。藉由使用C-V測量HfO2絕緣層之電容值，以及XPS與 AFM個別分析主動層及絕緣層薄膜特性，用以佐證電性圖之結果。最後本實驗發現於350度大氣環境下進行一小時退火為最佳退火製程參數。

Me tal oxide semiconductor is considered to be the most competitive TFT material for last decade. It has several advantages such as great uniformity for large size display, low fabrication temperature and low production cost. For next generation display, the TFT device need be improve, spiecially in mobility. To get higher mobility with IZTO-TFT, high-k dielectric was used as a gate insulator in TFT structure. In order to pursue greater metal oxide TFT performance, IZTO was introduced as the active layer. Becauce IZTO-TFT have higher mobility than IGZO-TFT with the same dielectric about 30 (cm2/V s). However, the material properties of indium zinc tin oxide are relatively unstable, so this paper will anneal through high temperature furnace tubes to improve the characteristics and stability of the components, and to explore the effect of high temperature furnace tube annealing on components.
First, we tested the temperature and uniformity of the newly purchased high-temperature furnace tubes to determine whether the experimental environmental parameters were consistent. Next, the TFT elements were fabricated by using a shadow mask, which was conditioned by temperature, environment, and annealing time. In order to find the annealing environment parameters with the best component electrical characteristics, and explore the degradation mechanism under continuous bias stress application through the component stability test. By using C-V method capacitance value of the HfO2 insulating layer is measured, and the characteristics of the active layer and the insulating layer film are separately analyzed by XPS and AFM to prove the result of the electrical characteristic. Finally, this experiment found that annealing for one hour in a 350 degree atmosphere is the best annealing process parameter.

[1] J. F. Wager, "ZnO Transparent Thin-Film Transistor Device Physics," Science, vol. 300, no. 5623, pp. 1245-1246, 2003.
[2] N. Munzenrieder, C. Zysset, T. Kinkeldei and G. Troster, "Design Rules for IGZO Logic Gates on Plastic Foil Enabling Operation at Bending Radii of 3.5 mm," IEEE Transactions on Electron Devices, vol. 59, no. 8, pp. 2153-2159, 2012.
[3] K. Nomura, 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, no. 25, pp. 488-492, 2004.
[4] 王木俊 且 劉傳璽, 薄膜電晶體液晶顯示器原理與實務, 新文京開發出版股份有限公司, 2008.
[5] 陳金鑫 且 黃孝文, OLED 夢幻顯示器, 五南圖書出版社股份有限公司, 2007.
[6] B. Y. Tsui and H. W. Chang, "Formation of interfacial layer during reactive sputtering of hafnium oxide," Journal of Applied Physics, vol. 93, pp. 10119-10124, 2003.
[7] S. H. Lo, D. A. Buchanan, Y. Taur and W. Wang, "Quantum-mechanical modeling of electron tunneling current from the inversion layer of ultra-thin-oxide nMOSFET's," IEEE Electron Device Letters, vol. 18, no. 5, pp. 209-211, 1997.
[8] P. Zurcher, C. J. Tracy, R. E. Jones Jr, P. Alluri, P. Y. Chu, B. Jiang, M. Kim, B. M. Melnick, M. V. Raymond, D. Roberts, T. P. Remmel, T. L. Tsai, B. E. White, S. Zafar and S. J. Gillespie, "Barium Strontium Titanate Capacitors for Embedded Dram," Materials Research Society Symposium Proceedings, vol. 541, pp. 11-22, 1999.
[9] A. Grill, "Electrode structures for integration of ferroelectric or high dielectric constant films in semiconductor devices," Materials Research Society Symposium Proceedings, vol. 541, pp. 89-99, 1999.
[10] K. J. Hubbard and D. G. Schlom, "Thermodynamic stability of binary oxides in contact with silicon," Journal of Materials Research, vol. 11, no. 11, pp. 2757-2776, 1996.
[11] B. Cheng, M. C. Cao, R. Rao, A. Inani, P. V. Voorde, W. M. Greene, J. M. C. Stork, Z. Yu, M. Zeitzoff and J. C. S. Woo, "The impact of High-k gate dielectrics and metal gate electrodes on Sub-100 nm MOSFETs," IEEE Transactions on Electron Devices, vol. 46, no. 7, pp. 1537-1544, 1999.
[12] M. H. Cho, Y. S. Roh, C. N. Whang, K. Jeong, S. W. Nahm, D. H. Ko, J. H. Lee, N. I. Lee and K. Fujihara, "Thermal stability and structural characteristics of HfO2 films on Si (100) grown by atomic-layer deposition," Applied Physics Letters, vol. 81, no. 3, pp. 472-474, 2002.
[13] M. H. Cho, D. H. Ko, Y. G. Choi, K. Jeong, I. W. Lyo, D. Y. Noh, H. J. Kim and C. N. Whang, "Thickness dependence of Y2O3 films grown on an oxidized Si surface," Journal of Vacuum Science & Technology A, vol. 19, no. 1, pp. 200-206, 2001.
[14] B. H. Lee, Y. Jeon, K. Zawadzki, W. J. Qi and J. Lee, "Effects of interfacial layer growth on the electrical characteristics of thin titanium oxide films on silicon," Applied Physics Letters, vol. 74, no. 21, pp. 3143-3145, 1999.
[15] V. Mikhelashvili and G. Eisenstein, "Effects of annealing conditions on optical and electrical characteristics of titanium dioxide films deposited by electron beam evaporation," Journal of Applied Physics, vol. 89, no. 6, pp. 3256-3269, 2001.
[16] J. Robertson, "Band offsets of wide-band-gap oxides and implications for future electronic devices," Journal of Vacuum Science & Technology B, vol. 18, no. 3, pp. 1785-1791, 2000.
[17] G. D. Wilk, R. M. Wallace and J. M. Anthony, "High-K gate dielectrics: Current status and materials properties considerations," Journal of Applied Physics, vol. 89, no. 10, pp. 5243-5275, 2001.
[18] D. C. Hsu, Y. K. Chang, M. T. Wang, P. C. Juan, Y. L. Wang and J. Y. M. Lee, "The positive bias temperature instability of nn-channel metal-oxide-semiconductor field-effect transistors with ZrO2 gate dielectric," Applied Physics Letters, vol. 92, p. 202901, 2008.
[19] B. H. Lee, L. Kang, W. J. Qi, R. Nieh, Y. Jeon, K. Onishi and J. C. Lee, "Ultrathin hafnium oxide with low leakage and excellent reliability for alternative gate dielectric application," Technical Digest-International Electron Devices Meeting, vol. 1999, pp. 133-136, 1999.
[20] I. Barin, Thermochemical Data of Pure Substances, VCH, Weiheim, 1989.
[21] A. Convertino, A. Valentini, T. Ligonzo and R. Cingolani, "Organic–inorganic dielectric multilayer systems as high reflectivity distributed Bragg reflectors," Applied Physics Letters, vol. 71, p. 732, 1997.
[22] N. Miyata, M. Ichikawa, T. Nabatame, T. Horikawa and A. Toriumi, "Thermal stability of a thin HfO2/ultrathin SiO2/Si structure: Interfacial Si oxidation and silicidation," Japanese Jouranl of Applied Physics, vol. 42, pp. 138-140, 2003.
[23] K. J. Choi, W. C. Shin and S. G. Yoon, "Ultrathin HfO2 gate dielectric grown by plasma-enhanced chemical vapor deposition using Hf[OC(CH3)3]4 as a precursor in the absence of O2," Journal of Materials Research, vol. 18, no. 1, pp. 60-65, 2003.
[24] L. Pereira, A. Marques, H. Aguas, N. Nedev, S. Georgiev, E. Fortunato and R. Martins, "Performances of hafnium oxide produced by radio frequency sputtering for gate dielectric application," Materials Science and Engineering B, vol. 109, pp. 89-93, 2004.
[25] O. Renault, D. Samour, D. Rouchon, P. Holliger, A. M. Papon, D. Blin and S. Marthon, "Interface properties of ultra-thin HfO2 films grown by atomic layer deposition on SiO2/Si," Thin Solid Films, vol. 428, pp. 190-194, 2003.
[26] M. Orita, H. Ohta, M. Hirano, S. Narushima and H. Hosono, "Amorphous transparent conductive oxide InGaO3 (ZnO)m (m≤ 4): a Zn4s conductor," Philosophical Magazine Part B, vol. 81, no. 5, pp. 501-515, 2001.
[27] D. C. Paine, T. Whitson, D. Janiac, R. Beresford, C. Ow-Yang and B. Lewis, "A study of low temperature crystallization of amorphous thin film indium-tin-oxide," Journal of Applied Physics, vol. 85, no. 12, pp. 8445-8450, 1999.
[28] M. Yasukawa, H. Hosono, N. Ueda and H. Kawazoe, "Novel Transparent and Electroconductive Amorphous Semiconductor: amorphous AgSbO3 Film.," Journal of Applied Physics, vol. 34, no. 3A, pp. L281-L284, 1995.
[29] E. Arca, K. Fleischer and I. V. Shvets, "Magnesium, nitrogen codoped Cr2O3: A p-type transparent conducting oxide," Applied Physics Letters, vol. 99, no. 11, p. 111910, 2011.
[30] Y. Ogo, H. Hiramatsu, K. Nomura, H. Yanagi, T. Kamiya, M. Hirano and H. Hosono, "p-channel thin-film transistor using p-type oxide semiconductor, SnO," Applied Physics Letters, vol. 93, no. 3, p. 032113, 2008.
[31] H. Hiramatsu, K. Ueda, H. Ohta, M. Hirano, T. Kamiya and H. Hosono, "Degenerate p-type conductivity in wide-gap LaCuOS1−xSex (x=0–1) epitaxial film," Applied Physics Letters, vol. 82, no. 7, p. 1048, 2003.
[32] A. J. Bosman and C. Crevecoeur, "Mechanism of the Electrical Conduction in Li-Doped NiO," Physical Review, vol. 144, no. 2, pp. 763-770, 1966.
[33] M. L. Tu, Y. K. Su and C. Y. Ma, "Nitrogen-doped p-type ZnO films prepared from nitrogen gas radio-frequency magnetron sputtering," Journal of Applied Physics, vol. 100, no. 5, p. 053705, 2006.
[34] D. C. Look, G. M. Renlund, R. H. Burgener II and J. R. Sizelove, "As-doped p-type ZnO produced by an evaporation/sputtering process," Applied Physics Letters, vol. 85, no. 22, pp. 5269-5271, 2004.
[35] Y. Ohya, H. Saiki and Y. Takahashi, "Preparation of transparent, electrically conducting ZnO film from zinc acetate and alkoxide," Journal of Materials Science, vol. 29, no. 15, pp. 4099-4103, 1994.
[36] R. L. Huffman, "Zno-channel thin-film transistors: Channel mobility," Journal of Applied Physics, vol. 95, no. 10, pp. 5813-5819, 2004.
[37] H. Hosono, "Ionic amorphous oxide semiconductors: Material design, carrier transport, and device application," Journal of Non-Crystalline Solids, vol. 352, pp. 851-858, 2006.
[38] H. Hosono, K. Nomura, Y. Ogo, T. Uruga and T. Kamiya, "Factors controlling electron transport properties in transparent amorphous oxide semiconductors," Journal of Non-Crystalline Solids, vol. 354, pp. 2796-2800, 2008.
[39] H. Q. Chiang, J. F. Wager, R. L. Hoffman, J. Jeong and D. A. Keszler, "High mobility transparent thin-film transistors with amorphous zinc tin oxide channel layer," Applied Physics Letters, vol. 86, no. 1, p. 013503, 2005.
[40] M. Orita, H. Ohta, M. Hirano, S. Narushima and H. Hosono, "Amorphous transparent conductive oxide InGaO3(ZnO)m (m ≤ 4): A Zn 4s conductor," Philosophical Magazine B, vol. 81, no. 5, pp. 501-515, 2001.
[41] H. Hosono, M. Yasukawa and H. Kawazoe, "Novel oxide amorphous semiconductors: Transparent conducting amorphous oxides," Journal of Non-Crystalline Solids, vol. 203, pp. 334-344, 1996.
[42] J. Y. Noh, H. Kim, H. H. Nahm, Y.S. Kim, D. H. Kim, B.D . Ahn, J. H. Lim, G. H. Kim, J. H. Lee, and J. Song, "Cation composition effects on electronic structures of In-Sn-ZnO amorphous semiconductors" Journal of Applied Physics, vol. 113, p.183706, 2013
[43] T. Kamiya, K. Nomura and H. Hosono, "Present status of amorphous In–Ga–Zn–O thinfilm transistors" Science and Technology of Advancedmaterials, vol. 11, p. 044305, 2010
[44] K. Takechi, M. Nakata, T. Eguchi, H. Yamaguchi and S. Kaneko, "Comparison of ultraviolet photo-field effects between hydrogenated amorphous silicon and amorphous InGaZnO4 thin-film transistors," Japanese Journal of Applied Physics, vol. 48, no. 1, p. 010203, 2009.
[45] 戴亞翔, TFT-LCD 面板的驅動與設計, 五南圖書出版社股份有限公司, 2008.
[46] J. S. Park, J. K. Jeong, Y. G. Mo, H. D. Kim and C. J. Kim, "Control of threshold voltage in ZnO-based oxide thin film transistors," Applied Physics Letters, vol. 93, no. 3, p. 033513, 2008.
[47] P. Barquinha, L. Pereira, G. Gonalves, R. Martins and E. Fortunato, "The effect of deposition conditions and annealing on the performance of high-mobility GIZO TFTs," Electrochemical and Solid-State Letters, vol. 11, no. 9, pp. H248-H251, 2008.
[48] J. H. Jeong, H. W. Yang, J. S. Park, J. K. Jeong, Y. G. Mo, H. D. Kim, J. Song and C. S. Hwang, "Origin of subthreshold swing improvement in amorphous indium gallium zinc oxide transistors," Electrochemical and Solid-State Letters, vol. 11, no. 6, pp. H157-H159, 2008.
[49] K. Ide, Y. Kikuchi, K. Nomura, M. Kimura, T. Kamiya and H. Hosono, "Effects of excess oxygen on operation characteristics of amorphous In-Ga-Zn-O thin-film transistors," Applied Physics Letters, vol. 99, no. 9, p. 093507, 2011
[50] P. Barquinha, A. M. Vila, G. Goncalves, L. Pereira, R. Martins, J. R. Morante and E. Fortunato, "Gallium-indium-zinc-oxide-based thin-film transistors: Influence of the source/drain material," IEEE Transactions on Electron Devices, vol. 55, no. 4, pp. 954-960, 2008.
[51] R. Yao et al., "Low-temperature fabrication of sputtered high-k HfO2 gate dielectric for flexible a-IGZO thin film transistors," Applied Physics Letters, vol. 112, no. 10, 2018.
[52] P. Kondaiah, H. Shaik, and G. Mohan Rao, "Studies on RF magnetron sputtered HfO2 thin films for microelectronic applications," Electronic Materials Letters, vol. 11, no. 4, pp. 592-600, 2015.
[53] F.-H. Chen et al., "Effect of surface roughness on electrical characteristics in amorphous InGaZnO thin-film transistors with high-κ Sm2O3 dielectrics," Journal of Physics and Chemistry of Solids, vol. 74, no. 4, pp. 570-574, 2013.
[54] C.-S. Fuh, P.-T. Liu, W.-H. Huang, and S. M. Sze, "Effect of Annealing on Defect Elimination for High Mobility Amorphous Indium-Zinc-Tin-Oxide Thin-Film Transistor," IEEE Electron Device Letters, vol. 35, no. 11, pp. 1103-1105, 2014.
[55] I. Noviyana et al., "High Mobility Thin Film Transistors Based on Amorphous Indium Zinc Tin Oxide," Materials (Basel), vol. 10, no. 7, Jun 26 2017.
[56] R. Li et al., "Effect of thermal annealing on the electrical characteristics of an amorphous ITZO:Li thin film transistor fabricated using the magnetron sputtering method," Materials Science in Semiconductor Processing, vol. 96, pp. 8-11, 2019.
[57] Y.-H. Lin and J.-C. Chou, "Temperature Effects on a-IGZO Thin Film Transistors Using HfO2 ate Dielectric Material," Journal of Nanomaterials, vol. 2014, pp. 1-5, 2014.
[58] A. Vinod, M. S. Rathore, and N. Srinivasa Rao, "Effects of annealing on quality and stoichiometry of HfO2 thin films grown by RF magnetron sputtering," Vacuum, vol. 155, pp. 339-344, 2018.
[59] S. W. Jeong et al., "Effects of annealing temperature on the characteristics of ALD-deposited HfO2 in MIM capacitors," Thin Solid Films, vol. 515, no. 2, pp. 526-530, 2006.
[60] T.-M. Pan, B.-J. Peng, and C.-H. Chen, "Structural and electrical properties of high-κ CeTixOy, rTixOy and YbTixOy gate dielectrics for InZnSnO thin film transistors," Journal of Alloys and Compounds, vol. 722, pp. 637-643, 2017.
[61] G. H. Kim, H. S. Kim, H. S. Shin, B. D. Ahn, K. H. Kim, and H. J. Kim, "Inkjet-printed InGaZnO thin film transistor," Thin Solid Films, vol. 517, no. 14, pp. 4007-4010, 2009.
[62] M. Chen, Z. L. Pei, C. Sun, L. S. Wen, X. Wang,” Surface characterization of transparent conductive oxide Al-doped ZnO," Journal of Crystal, vol. 220, pp. 254-262, 2000.
[63] W. Zhong, G. Li, L. Lan, B. Li, and R. Chen, "Effects of annealing temperature on properties of InSnZnO thin film transistors prepared by Co-sputtering," RSC Advances, vol. 8, no. 61, pp. 34817-34822, 2018.
[64] K. H. Kim et al., "Non-Stoichiometric Indium Zinc Tin Oxide Thin Films Prepared by RF Magnetron Sputtering," Journal of Nanoelectronics and Optoelectronics, vol. 10, no. 4, pp. 541-545, 2015.
[65] Y. S. Chun, S. Chang and S. Y. Lee, "Effects of gate insulators on the performance of a-IGZO TFT fabricated," Microelectronic Engineering, vol. 88, no. 7, pp. 1590-1593, 2011.
[66] S. Y. Lee, S. Chang and J. S. Lee, "Role of high-k gate insulators for oxide thin film transistors," Thin Solid Films, vol. 518, no. 11, pp. 3030-3032, 2010. 71717171
[67] G. Li et al., "Nitrogen-Doped Amorphous InZnSnO Thin Film Transistors With a Tandem Structure for High-Mobility and Reliable Operations," IEEE Electron Device Letters, vol. 37, no. 5, pp. 607-610, 2016.
[68] S. Choi et al., "The Effect of Gate and Drain Fields on the Competition Between Donor-Like State Creation and Local Electron Trapping in In–Ga–Zn–O Thin Film Transistors Under Current Stress," IEEE Electron Device Letters, vol. 36, no. 12, pp. 1336-1339
[69] J. Q. Song, L. X. Qian, and P. T. Lai, "Improved Performance of Amorphous InGaZnO Thin-Film Transistor by Hf Incorporation in La2O3 Gate Dielectric," IEEE Transactions on Device and Materials Reliability, vol. 18, no. 3, pp. 333-336, 2018.
[70] C.-S. Fuh, S. M. Sze, P.-T. Liu, L.-F. Teng, and Y.-T. Chou, "Role of environmental and annealing conditions on the passivation-free In-Ga–Zn–O TFT," Thin Solid Films, vol. 520, no. 5, pp. 1489-1494, 2011.
[71] S. Park, S. Bang, S. Lee, J. Park, Y. Ko, and H. Jeon, "The Effect of Annealing Ambient on the Characteristics of an Indium–Gallium–Zinc Oxide Thin Film Transistor," Journal of Nanoscience and Nanotechnology, vol. 11, no. 7, pp. 6029-6033, 2011.
[72] S.-U. Lee and J. Jeong, "Short time helium annealing for solution-processed amorphous indium-gallium-zinc-oxide thin-film transistors," AIP Advances, vol. 8, no. 8, 2018.
[73] Y.-H. Wang et al., "Performance Improvement of Atomic Layer-Deposited ZnO/Al2O3 Thin-Film Transistors by Low-Temperature Annealing in Air," IEEE Transactions on Electron Devices, vol. 63, no. 5, pp. 1893-1898, 2016.
[74] W. Cabrera et al., "Diffusion of In0.53Ga0.47As elements through hafnium oxide during post deposition annealing," Applied Physics Letters, vol. 104, no. 1, 2014.
[75] H.-J. RYU et al., " Indium-Tin Oxide/Si Contacts with In- and Sn-Diffusion Barriers in Polycrystalline Si Thin-Film Transistor Liquid-Crystal Displays,” Journal of ELECTRONIC MATERIALS, vol. 32, no. 9, 2003.
[76] S.-U. Lee and J. Jeong, "Short time helium annealing for solution-processed amorphous indium-gallium-zinc-oxide thin-film transistors," AIP Advances, vol. 8, no. 8, 2018.
[77] J. Seonghyun, K. Tae-Woong, S. Young-Gug, M. Mativenga, and J. Jin, "Reduction of Positive-Bias-Stress Effects in Bulk-Accumulation Amorphous-InGaZnO TFTs," IEEE Electron Device Letters, vol. 35, no. 5, pp. 560-562, 2014.
[78] H. Tang, K. Ide, H. Hiramatsu, S. Ueda, N. Ohashi, H. Kumomi, H. Hosono, T. Kamiya, "Effects of thermal annealing on elimination of deep defects in amorphous In–Ga–Zn–O thin-film transistors", Thin Solid Films, vol. 614, pp. 73–78, 2016.