臺灣博碩士論文加值系統

本研究利用電漿輔助化學氣相沉積(Plasma enhanced chemical vapor deposition ,PECVD) 製備超薄氫化非晶矽薄膜在粗糙化矽晶基板表面鈍化以應用於異質接面太陽能電池。研究中主要分為兩個部分，其一為利用調變射頻功率、氫稀釋比例、電極間距、基板溫度等製程參數探討對氫化非晶矽(a-Si:H)薄膜於粗糙化矽晶基板上鈍化特性影響，並在製程中搭配光放射光譜儀(OES) 與四極柱質譜儀(QMS)量測作為解析電漿物種及電漿反應機制，其二為經由不同晶片潔淨處理方式以優化薄膜與晶片介面間的品質，使得鈍化成效能更進一步提升。在分析薄膜結構特性上先以橢圓偏光儀量測薄膜厚度，再以少數載子生命週期來判斷薄膜鈍化品質優劣，最後經由快速熱退火處理作為進一步鈍化效果提升及確認與優化薄膜結構的依據。
　　研究結果顯示，透過OES和QMS電漿診斷確實有助於解析電漿物種及電漿反應機制，並在薄膜特性與鈍化品質分析上有所幫助，更能增加在製程分析上的準確性及提高製程穩定性與效率，因此在粗糙化矽晶基板上沉積氫化非晶矽薄膜製程參數中，我們可於H2/SiH4=7.3、射頻功率30W、製程壓力300mtorr、製程溫度300 ℃(實際溫度約為154 oC)的條件下得到約12nm 超薄氫化非晶矽薄膜，搭配選用適合的晶片處理方式提升介面品質可獲得最佳鈍化效果，少數載子生命週期可達到690μsec，Implied Voc值可達到約0.69V，相當於粗化矽晶表面復合速率可下降至12 cm/s的良好鈍化效果。

In this study, the intrinsic hydrogenated amorphous silicon (a-Si:H) thin films deposited on the textured silicon substrate for application in heterojunction with intrinsic thin layer (HIT) solar cell was prepared by Plasma Enhanced Chemical Vapor Deposition (PECVD). The passivation quality of a-Si:H thin films was investigated by modulating the process parameters such as power, distance, dilution ratio, and substrate temperature. During the process, OES (Optical emission spectrometer) was used to diagnose the variation of plasma species, and QMS (Quadrupole mass spectrometry) was utilized to determine the concentration of free radicals in plasma. We changed different method of wafer cleaning to improve the interface between substrate and thin film. The thickness and the characteristics of thin film were measured and further analyzed by Spectroscopic Ellipsometer. The surface passivation quality of thin film was determined by photo-conductance lifetime tester. We also used annealing treatment to further improve the structure of a-Si:H thin films.
　　The results show that integrated QMS and OES is indeed a way to help us to analyze the mechanism of plasma, and by adjusting the process parameters, the property of amorphous silicon (a-Si:H) thin films is determined. A high passivation quality of a-Si:H thin films on the textured silicon substrate was obtained under the conditions of H2/SiH4=7.3, power of 30W, working pressure of 300mtorr , substrate temperature of 300℃,and appropriate wafer cleaning. The effective lifetime of a-Si:H film increased to 690 μsec, the implied Voc increased to 0.69 V and the surface recombination velocity (SRV) was also reduced to 12 cm/s.

摘要 vi
Abstract vii
致謝 viii
目錄 ix
圖目錄 xii
表目錄 xviii
第一章 緒論 1
1-1前言 1
1-2太陽能電池發展背景 3
1-3研究動機及研究方法 6
1-4 論文架構 8
第二章 基本原理與文獻回顧 9
2-1太陽能電池基本原理 9
2-2-1 異質接面矽晶太陽能電池介紹 11
2-2薄膜沉積與介紹 12
2-2-1 化學氣相沉積(Chemical vapor deposition) 12
2-2-2 氫化非晶矽薄膜介紹 14
2-2-3 氫化非晶矽薄膜成長機制 15
2-3載子生命週期復合機制 19
2-4太陽能電池的高效率化 23
2-4-1表面粗糙化結構 24
2-4-2鈍化原理與機制 26
2-5電漿診斷系統 28
2-5-1光放射光譜儀(OES) 28
2-5-2四極柱質譜儀(QMS) 31
2-6氫化非晶矽之鈍化研究與應用 33
第三章 研究方法與實驗設備 38
3-1 實驗方法 38
3-2 樣品製備流程 39
3-2-1 基板清洗 39
3-2-2本質非晶矽薄膜的製備 40
3-3 實驗裝置與量測設備 40
3-3-1 電漿輔助化學氣相沈積系統(PECVD) 40
3-3-2 橢圓偏光儀 (Ellipsometer) 43
3-3-3 光電導生命週期量測儀 (Photoconductance lifetime tester) 44
3-3-4 快速熱退火 ARTS-RTA 46
3-3-5 光放射光譜儀OES 47
3-3-6 四極柱質譜儀QMS 50
第四章 實驗結果與討論 56
4-1 本質層薄膜品質最佳化 57
4-1-1氫稀釋濃度 57
4-1-2電極間距 66
4-1-3製程壓力 78
4-1-4 P(製程壓力)╳D(電極間距) 85
4-1-5射頻功率 89
4-1-6製程溫度 99
4-2 本質層薄膜與介面間的優化 103
第五章 結論與未來展望 111
5-1 結論 111
5-2 未來展望 117
參考文獻 118

[1] 臺灣能源統計年報，2014，http://web3.moeaboe.gov.tw/.
[2] Annual Energy Outlook，2015，http://www.eia.gov/todayinenergy/
[3] United Nations Climate Change Conference，2015，http://www.cop21.gouv.fr/.
[4] 黃惠良，曾百亨，太陽電池，五南出版社，民國97 年12 月。
[5] 顧鴻濤，太陽能電池元件導論，全威圖書有限公司，台北，民國97 年。
[6] Swanson, “A vision for crystalline silicon photovoltaics”, Progress in Photovoltaics, Vol. 14, pp. 443-453, 2006.
[7] H. Sakata and M. Tanaka, “Sanyo’s Challenges to the Development of High-efficiency HIT Solar Cells and the Expansion of HIT Business”, IEEE 4th World Conference, 2006.
[8] ITRPV Edition 2016_Revision 1，2016，http://www.itrpv.net/Home/.
[9] M. Taguchi, et al. “Obtaining a Higher Voc in HIT Cells”, Progress in Photovoltaics: Research and Applications, Vol. 13, pp. 481-488, 2005.
[10] Yang H, et al. “Optical emission spectroscopy investigation on very high frequency plasma and its glow discharge mechanism during the microcrystalline silicon deposition”, Thin Solid Films, Vol.472, pp.125-129, 2005.
[11] Donald A. Neamen, Semiconductor Physics and Devices: Basic Principles ,(4e), McGraw-Hill, (2012).
[12] M. S. Valipa, E. S. Aydil and D. Maroudas, “Atomistic calculation of the SiH3 surface reactivity during plasma deposition of amorphous silicon thin films”, Surface Science, Vol. 572, pp. 339-347, 2004.
[13] F.Pelanchon, et al. “The photocurrent and the open circuit voltage of a silicon solar cell”, Solar cells, Vol. 28(1), pp.41-55, 1990.
[14] M. Taguchi, A. Yano, S. Tohoda, and K. Matsuyama, “24.7% Record Efficiency HIT Solar Cell on Thin Silicon Wafer”, IEEE Journal of photovoltaics , Vol. 4, NO. 1, (2014).
[15] 莊達人編著, VLSI 製造技術, 高立圖書有限公司, p. 357, (1996).
[16] V. Keudell and J. R. Abelson, “Direct insertion of SiH3 radicals into strained Si-Si surface bonds during plasma deposition of hydrogenated amorphous silicon films”, Physical Review B, Vol. 59, no. 8, Article ID 5791,1999.
[17] R.Schrop and M.Zeman, Amorphous and Microcrystalline Silicon Solar Cells: Modeling, Materials and Device Technology, Kluwer Academic, Boston, 1998.
[18] A.V. Shah, J. Meier, E. Vallat-Sauvain, N. Wyrsch, U. Kroll, C. Droz, U. Graf , “Material and solar cell research in microcrystalline silicon ”, Solar Energy Materials and Solar Cells, Vol 78, pp. 469-491, 2003.
[19] O. Vetterl, F. Finger, R. Carius, P. Hapke, L. Houben, O. Kluth, A. Lambertz, A. MuK ck, B. Rech, H. Wagner, “Intrinsic microcrystalline silicon:A new material for photovoltaics”, Solar Energy Materials and Solar Cells, Vol 62, pp. 97-108, 2000.
[20] A. Matsuda, ”Growth mechanism of microcrystalline silicon obtained from reactive plasmas”, Thin Solid Films, Vol 337, pp. 1-6, 1999.
[21] A. Matsuda, M. Takai, T. Nishimoto, and M. Kondo,“Control of plasma chemistry for preparing highly stabilized amorphous silicon at high growth rate”, Solar Energy &Solar Cells, Vol.78, pp.3-26, 2003.
[22] A. Matsuda and K. Tanaka, Thin Solar Film 92,171, 1982.
[23] A. Matsuda, in Conference Record of the 25th IEEE photovoltaic Specialist Conference (IEEE, New York, 1996) p.1029, 1996.
[24] M. Kishner, “On the balance between silylene and silyl radicals in rf glow discharges in silane: The effect on deposition rates of a-Si:H”, Journal of Applied Physics, Vol. 62, pp. 2803-2811, 1987.
[25] A.Matsuda. “Thin-Film Silicon —Growth Process and Solar Cell Application”, Japanese Journal of Applied Physics, Vol 43, pp. 7909–7920, 2004.
[26] D. L. Meier, M. R. Page, E. Iwaniczko, Y, Xu, Q. Wang, H. M. Branz, “Determination of Surface Recombination Velocities for Thermal Oxide and Amorphous Silicon on Float Zone Silicon”, 17th NREL Crystalline Silicon Workshop, August, 2007.
[27] T. S. Horanyi, T. Pavelka and P. Tutto, “In situ bulk lifetime measurement on silicon with a chemically passivated surface”, Applied Surface Science, Vol. 63, pp. 306-311, 1993.
[28] Y. Tsunomura , Y. Yoshimine, M. Taguchi, T. Baba, T. Kinoshita, H. Kanno, H. Sakata, E. Maruyama, M. Tanaka, ” Twenty-two percent efficiency HIT solar cell”, Solar Energy Materials and Solar Cells 93 (2009) 670–673
[29] M. G. Kang , and S. Tark, “Changes in efficiency of a solar cell according to various surface-etching shapes of silicon substrate”, Journal of Crystal Growth , Vol. 326, p. 14– 18, (2011).
[30] Y. Yamamoto, et al. “Passivation Effect of Plasma Chemical Vapor Deposited SiNx on Single Crystalline Silicon Thin Film Solar Cells”, Japanese Journal of Applied Physics, Vol. 42, pp. 5135-5139, 2003.
[31] Burrows, M. Z., et al., “Role of hydrogen bonding environment in a-Si:H films for c-Si surface passivation”, Journal of Vacuum Science and Technology A,Vol. 26(4), pp. 683-687, 2008.
[32] J. Sritharathikhun, C. Banerjee, M. Otsubo, T. Sugiura, H. Yamamoto, T. Sato, A. Limmanee, A. Yamada and M. Konagai, “Surface Passivation of Crystalline and Polycrystalline Silicon Using Hydrogenated Amorphous Silicon Oxide Film”, Japanese Journal of Applied Physics, Vol. 46(6A), pp. 3296-3300, 2007.
[33] Y. Fukuda, et al. “Optical emission spectroscopy study toward high rate growth of microcrystalline silicon” ,Thin Solid Films, Vol.386, pp.256-260, 2001.
[34] H. Yang, C. Wu, J. Huang, R. Ding, Y. Zhaoa, X. Genga and S. Xionga, “Optical emission spectroscopy investigation on very high frequency plasma and its glow discharge mechanism during the microcrystalline silicon deposition”, Thin Solid Films, Vol 472, pp. 125–129, 2005.
[35] P. Kumar, F. Zhu and A. Madan, “Electrical and structural properties of nano-crystalline silicon intrinsic layers for nano-crystalline silicon solar cells prepared by very high frequency plasma chemical vapor deposition”, International Journal of Hydrogen Energy, Vol 33, pp. 3938–3944, 2008.
[36] M. Takai, T. Nishimoto, M. Kondo and A. Matsuda et al., “Effect of higher-silane formation on electron temperature in a silane glow-discharge plasma”, Applied Physics Letters, Vol. 77, pp. 18-22, 2000.
[37] A. Matsuda, M. Takai, T. Nishimoto and M. Kondo, “Control of plasma chemistry for preparing highly stabilized amorphous silicon at high growth rate”, Solar Energy Materials &Solar Cells, Vol 78, pp. 3–26, 2003.
[38] S. Ram, L. Kroely, S. Kasouit, P. Bulkin, and P.Roca et al., “Plasma emission diagnostics during fast deposition of microcrystalline silicon thin films in matrix distributed electron cyclotron resonance plasma CVD system”, Physica Status Solidi© , Vol. 7, pp. 553–556, 2010.
[39] J. Ge, Z. Ling, J. Wong, T. Mueller and A. Aberle et al., “Optimisation of Intrinsic a-Si:H Passivation Layers in Crystalline-amorphous Silicon Heterojunction Solar Cells”, Energy Procedia, Vol. 15, pp. 107-117, 2012.
[40] H. L. Hsiao, H. L. Hwang, A. B. Yang, L. W. Chen and T. R. Yew, “Study on low temperature facetting growth of polycrystalline silicon thin films by ECR downstream plasma CVD with different hydrogen dilution”, Applied Surface Science, Vol 142, pp. 316–321, 1999.
[41] T Moiseev, D Chrastina, G Isella and C Cavallotti, “Threshold ionization mass spectrometry in the presence of excited silane radicals”, J. Phys. D: Appl. Phys. Vol. 42, pp. 5-10, 2009.
[42] J. R. Doyle, D. A. Doughty, and A. Gallagher, “Silane dissociation products in deposition discharges”, Journal of Applied Physics, Vol 68, pp. 4375,1990.
[43] P Kae-Nune, J Perrin, J Guillon and J Jolly,” Mass spectrometry detection of radicals in SiH4-CH4-H2 glow discharge plasmas”, Plasma Sources Science Technology, Vol 9, pp. 250-259, 1995.
[44] M. Goto, H. Toyoda, M. Kitagawa, T. Hirao, and H.Sugai, “low temperature growth of amorphous and polycrystalline silicon films from a modified inductively coupled plasma”, Japanese Journal of Applied Physics, Vol. 36, pp. 3714-3720, 1997
[45] S. Xu, X. Zhang, Y.Li, S. Xiong, X. Geng, and Y. Zhao, “Improve silane utilization for silicon thin film deposition at high rate”, Thin Solid Film, Vol. 520, pp. 694-696, 2011.
[46] C. C. Tsai, G. B. Anderson and R. Thompson, “Low temperature growth of epitaxial and amorphous silicon in a hydrogen-diluted silane plasma”, Journal of Non-Crystalline Solids, Vol. 137&138, pp. 673-676, 1991.
[47] U. Kroll, J. Meier,A. Shah, S. Mikhailov, and J, Weber, Journal of Applied Physics, Vol 80, pp. 4971 , 1996.
[48] Norbert H. Nickel, Hydrogen in semiconductor II, Vol. 61 , 1999.
[49] M. Jeon, S. Yoshiba, K. Kamisako “Hydrogenated amorphous silicon film as intrinsic passivation layer deposited at various temperatures using RF remote-PECVD technique”, Current Applied Physics 10 S237–S240 , 2010.
[50] J. Ge, Z. P. Ling, J. Wong, R. Stangl, A. G. Aberle, and T. Mueller, “Analysis of intrinsic hydrogenated amorphous silicon passivation layer growth for use in heterojunction silicon wafer solar cells by optical emission spectroscopy” , Journal of Applied Physics, Vol. 113, pp.234-310 , 2013.
[51] B. Stegemann, J. Kegela, M. Mews, E. Conrad, L. Korte, U. Stürzebecher and H. Angermann, “Passivation of textured silicon wafers: Influence of pyramid size distribution, a-Si:H deposition temperature, and post-treatment”, Energy Procedia ,Vol. 38, pp. 881-889, 2013
[52] State of the art technology _ Solar Global _ Panasonic HIT，2016，http://panasonic.net/ecosolutions/solar/hit/
[53] 陳建勳，非晶矽繞射光學元件的製作與分析，p.10，國立中央大學物理研究所碩士論文，民國九十四年。
[54] P. Klement, C. Feser, B. Hanke, K. von Maydell, and C. Agert, "Correlation between optical emission spectroscopy of hydrogen/germane plasma and the Raman crystallinity factor of germanium layers", Applied. Physics. Letters, Vol. 102 ,152109, 2013
[55] Matsuda, M. Takai, T. Nishimoto, and M. Kondo, "Control of plasma chemistry for preparing highly stabilized amorphous silicon at high growth rate" , Solar Energy Materials and Solar Cells, Vol. 78, pp. 3-26 , 2003
[56] P. Tristant, Z. Ding, Q. B. Trang Vinh, H. Hidalgo, J. Jauberteau, J. Desmaison, and C. Dong et al., “Microwave Plasma Enhanced CVD of Aluminum Oxide Films：OES Diagnostics and Influence of the RF Bias”, Thin Solid Films, Vol. 390, pp. 51–58, 2001.
[57] 蔡旺霖，「微晶矽薄膜製程於高頻電漿反應器之電漿診斷與模型研究」，私立中原大學，碩士論文，2010年。
[58] A I. Chowdhury, T M. Klein, T M. Anderson, and G N. Parsons, “Silane consumption and conversion analysis in amorphous silicon and silicon nitride plasma deposition using in situ mass spectroscopy”, Journal of Vacuum Science & Technology A, Vol 16, pp. 1852, 1998
[59] S. Lien, Y. Chang, Y. Cho, J. Wang and K. Weng et al., “Characterization of HF-PECVD a-Si:H thin film solar cells by using OES studies”, Journal of Non-Crystalline Solids, Vol. 357, pp.161–164, 2011.
[60] U. K. Das, M. Z. Burrows, M. Lu, S. Bowden, and R. W. Birkmire,” Surface passivation and heterojunction cells on Si (100) and (111) wafers using dc and rf plasma deposited Si:H thin films”, Applied Physics Letters, Vol, 92, 063504 , 2008
[61] P. K. Chang, P. T. Hsieh, F. J. Tsai, C. H. Lu, C.H. Yeh, N. F. Wang, M. P. Houng ,” High efficiency amorphous silicon solar cells with high absorption coefficient intrinsic amorphous silicon layers”, Thin Solid Films, Vol. 520 , pp. 5042–5045, 2012
[62] 胡立成，「電子迴旋共振電漿於本質矽薄膜沉積製程之研究」，國立中央大學，機械工程學系研究所博士論文，民國104年
[63] 張善淵，「使用電子迴旋供震化學氣相沉積製備異質接面太陽能電池表面鈍化氫化非晶矽薄膜製程參數研究」，國立中央大學，能源工程研究所碩士論文，民國102年
[64] WIKIPEDIA，Paschen's law，https:// en.wikipedia.org/wiki/Paschen%
27s_law
[65] S. Kim, V. A. Dao, Y. Lee, C. Shin, J. Park, J. Cho, J. Yi, ” Processed optimization for excellent interface passivation quality of amorphous/crystalline silicon solar cells”, Solar Energy Materials & Solar Cells, Vol. 117, pp. 174–177, 2013
[66] T. F. Schulze, H. N. Beushausen, C. Leendertz, A. Dobrich, B. Rech et al., “Interplay of amorphous silicon disorder and hydrogen content with interface defects in amorphous/crystalline silicon heterojunctions”, Applied Physics Letters ,Vol. 96, 252102 , 2010.
[67] K. Reinhardt and W. Kern, Handbook of silicon wafer cleaning technology, 2nd ed. California USA, 2008, pp. 3–25.
[68] H. Angermann, W. Henrion, M. Rebien, and a. Röseler, “Wet-chemical preparation and spectroscopic characterization of Si interfaces,” Applied Surface Science, vol. 235, pp. 322–339, 2004.
[69] H. Angermann, J. Rappich, L. Korte, I. Sieber, E. Conrad, M. Schmidt, K. Hübener, J. Polte, and J. Hauschild, “Wet-chemical passivation of atomically flat and structured silicon substrates for solar cell application,” Applied Surface Science, vol. 254, pp. 3615–3625, 2008.
[70] S. Alivizatos, “Investigation of textured c-Si wafers for application in silicon heterojunction solar cells” , A thesis submitted for the degree of Master of Science in Sustainable Energy Technology at Delft University of Technology, 2013.
[71] W.S. Yan, D.Y. Wei, Y.N. Guo, S. Xu , T.M. Ong, C.C. Sern, “Low-temperature preparation of phosphorus doped μc-Si:H thin films by low-frequency inductively coupled plasma assisted chemical vapor deposition”, Thin Solid Films, Vol. 520, pp. 1724–1728, 2012.