本研究係在以較大面積(20×20 cm2)之射頻電漿輔助化學氣相沉積系統中，通入矽甲烷原料以不同製程條件於單晶矽表面沉積氫化非晶矽形成異質接合結構。研究重點在探究在此一沉積系統中氫化晶矽的鍍膜性質，期待找出對於單晶矽的表面鈍化效果較佳的長膜條件。
實驗結果顯示，在放電間距3 cm、電漿功率密度在1.59 mW/cm2時，有相對較小約1奈米的長膜表面粗糙度，其微結構參數為0.165。以此條件製作30奈米氫化非晶矽鈍化矽晶雙面後，於退火前晶片的載子生命期為1170 µs。另外調整原料進氣氫稀釋比為3的成長條件下，由RHEED繞射圖譜發現長膜已進入非晶與磊晶轉移區域，再經退火處理後，獲得晶片有效載子生命期為1630 µs、暗示開路電壓為718 mV。此時發現微結構參數大幅由0.15下降至0.03，顯示在低電漿功率密度的非晶矽長膜經退火處理後仍能展現良好的矽晶表面鈍化能力。

Hydrogenated amorphous Si (a-Si:H) thin films were deposited on single crystal Si (c-Si) wafers to form a-Si:H/c-Si heterojuction structure in large-area(20×20 cm2) radio-frequency plasma-enhanced chemical vapor deposition (large-area RF-PECVD) system. Emphasis was placed upon exploring the characteristics of a-Si:H film prepared in large-area RF-PECVD system and finding the optimized condition to obtain the high quality film which has less defect and dense structure. We expect to promote minority carrier lifetime of c-Si with these high quality films.
The result of experiment, when the discharge distance is 3 cm in large-area RF-PECVD system, it was found that film has a roughness layer thickness of 1.01 nm and a microstructure parameter of 0.165 at a minimum 1.59 mW / cm2 of plasma power density. When we deposited 30 nm a-Si:H on double side to passivate the polished silicon wafer, the as-deposited sample showes a minority carrier lifetime of 1170 µs. Therefore, we got more compact films at very low power density in large-area PECVD system.
In addition, when the hydrogen dilution ratio is 3, we observed that the amorphous/epitaxy transition by employing RHEED technique. The a-Si:H/c-Si heterojuction prepared under this condition showes a very high minority carrier lifetime of 1430 µs even for the as-deposited state. A further heat treatment promoted minority carrier lifetime only a little bit to 1630 µs, corresponding an implied Voc of 718 mV. The microstruture parameter down from 0.15 to 0.034, it shows that produce less microvoid after annealing, and have the best passivation performance.

[1]"Best Research-Cell Efficiencies," National Renewable Energy Laboratory, NREL, 2016.
[2]M. Stutzmann, D. K. Biegelsen, and R. A. Street, “Detailed investigation of doping in hydrogenated amorphous silicon and germanium,” Physical Review B, vol. 35, no. 11, pp. 5666-5701, 04/15/, 1987.
[3]M. H. Cohen, H. Fritzsche, and S. R. Ovshinsky, “Simple Band Model for Amorphous Semiconducting Alloys,” Physical Review Letters, vol. 22, no. 20, pp. 1065-1068, 05/19/, 1969.
[4]E. A. Davis, and N. F. Mott, “Conduction in non-crystalline systems V. Conductivity, optical absorption and photoconductivity in amorphous semiconductors,” Philosophical Magazine, vol. 22, no. 179, pp. 0903-0922, 1970.
[5]D. E. Carlson, and C. R. Wronski, "Amorphous silicon solar cells," Amorphous Semiconductors, M. H. Brodsky, ed., pp. 287-329, Berlin, Heidelberg: Springer Berlin Heidelberg, 1985.
[6]A. Shah, H. Schade, M. Vanecek, J. Meier, E. Vallat‐Sauvain, N. Wyrsch, U. Kroll, C. Droz, and J. Bailat, “Thin‐film silicon solar cell technology,” Progress in photovoltaics: Research and applications, vol. 12, no. 2‐3, pp. 113-142, 2004.
[7]M. Tsuda, S. Oikawa, and K. Sato, “On the primary process in the plasma‐chemical and photochemical vapor deposition from silane. III. Mechanism of the radiative species Si*(1 P 0) formation,” The Journal of chemical physics, vol. 91, no. 11, pp. 6822-6829, 1989.
[8]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 and Solar Cells, vol. 78, no. 1, pp. 3-26, 2003/07/01/, 2003.
[9]J. Stuke, and W. Brenig, “Amorphous and liquid semiconductors (Proceedings of the 5 th International conference on Amorphous and liquid semiconductors),” 1974.
[10]W. Paul, G. Connell, and R. Temkin, “Amorphous germanium I. A model for the structural and optical properties,” Advances in Physics, vol. 22, no. 5, pp. 531-580, 1973.
[11]J. C. Knights, G. Lucovsky, and R. J. Nemanich, “Defects in plasma-deposited a-Si: H,” Journal of Non-Crystalline Solids, vol. 32, no. 1, pp. 393-403, 1979/02/01/, 1979.
[12]R. A. Street, J. C. Knights, and D. K. Biegelsen, “Luminescence studies of plasma-deposited hydrogenated silicon,” Physical Review B, vol. 18, no. 4, pp. 1880-1891, 08/15/, 1978.
[13]P. D'Antonio, and J. H. Konnert, “Small-angle-scattering evidence of voids in hydrogenated amorphous silicon,” Physical Review Letters, vol. 43, no. 16, pp. 1161, 1979.
[14]D. Jousse, E. Bustarret, and F. Boulitrop, “Disorder and defects in sputtered a-SiH from subgap absorption measurements,” Solid State Communications, vol. 55, no. 5, pp. 435-438, 1985/08/01/, 1985.
[15]A. H. Mahan, D. L. Williamson, B. P. Nelson, and R. S. Crandall, “Small-angle X-ray scattering studies of microvoids in a-SiC:H and a-Si:H,” Solar Cells, vol. 27, no. 1, pp. 465-476, 1989/10/01/, 1989.
[16]M. Brodsky, M. Cardona, and J. Cuomo, “Infrared and Raman spectra of the silicon-hydrogen bonds in amorphous silicon prepared by glow discharge and sputtering,” Physical Review B, vol. 16, no. 8, pp. 3556, 1977.
[17]H. Shanks, C. Fang, L. Ley, M. Cardona, F. Demond, and S. Kalbitzer, “Infrared spectrum and structure of hydrogenated amorphous silicon,” physica status solidi (b), vol. 100, no. 1, pp. 43-56, 1980.
[18]M. Cardona, “Vibrational spectra of hydrogen in silicon and germanium,” physica status solidi (b), vol. 118, no. 2, pp. 463-481, 1983.
[19]J. Knights, G. Lucovsky, and R. Nemanich, “Hydrogen bonding in silicon-hydrogen alloys,” Philosophical Magazine B, vol. 37, no. 4, pp. 467-475, 1978.
[20]G. Lucovsky, R. Nemanich, and J. Knights, “Structural interpretation of the vibrational spectra of a-Si: H alloys,” Physical Review B, vol. 19, no. 4, pp. 2064, 1979.
[21]W. Pollard, and G. Lucovsky, “Phonons in polysilane alloys,” Physical Review B, vol. 26, no. 6, pp. 3172, 1982.
[22]A. Smets, and M. Van De Sanden, “Relation of the Si H stretching frequency to the nanostructural Si H bulk environment,” Physical Review B, vol. 76, no. 7, pp. 073202, 2007.
[23]J. Ramanujam, and A. Verma, “Photovoltaic properties of a-Si: H films grown by plasma enhanced chemical vapor deposition: a review,” Materials Express, vol. 2, no. 3, pp. 177-196, 2012.
[24]S. Shimizu, A. Matsuda, and M. Kondo, “Stability of thin film solar cells having less-hydrogenated amorphous silicon i-layers,” Solar Energy Materials and Solar Cells, vol. 92, no. 10, pp. 1241-1244, 2008.
[25]N. Nakamura, T. Takahama, M. Isomura, M. Nishikuni, K. Yoshida, S. Tsuda, S. Nakano, M. Ohnishi, and Y. Kuwano, “The Influence of the Si-H2 Bond on the Light-Induced Effect in a-Si Films and a-Si Solar Cells,” Japanese Journal of Applied Physics, vol. 28, no. 10R, pp. 1762, 1989.
[26]D. Staebler, and C. R. Wronski, “Optically induced conductivity changes in discharge‐produced hydrogenated amorphous silicon,” Journal of Applied Physics, vol. 51, no. 6, pp. 3262-3268, 1980.
[27]H.-Y. Kim, J.-B. Choi, and J.-Y. Lee, “Effects of silicon–hydrogen bond characteristics on the crystallization of hydrogenated amorphous silicon films prepared by plasma enhanced chemical vapor deposition,” Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, vol. 17, no. 6, pp. 3240-3245, 1999.
[28]H. Neitzert, W. Hirsch, and M. Kunst, “Structural changes of a-Si: H films on crystalline silicon substrates during deposition,” Physical Review B, vol. 47, no. 7, pp. 4080, 1993.
[29]M. Z. Burrows, U. K. Das, R. L. Opila, S. De Wolf, and R. W. Birkmire, “Role of hydrogen bonding environment in a-Si:H films for c-Si surface passivation,” Journal of Vacuum Science & Technology A, vol. 26, no. 4, pp. 683-687, 2008.
[30]H. Fujiwara, and M. Kondo, “Impact of epitaxial growth at the heterointerface of a-Si:H∕c-Si solar cells,” Applied Physics Letters, vol. 90, no. 1, pp. 013503, 2007.
[31]簡郡輝, “脈衝高頻電漿輔助化學氣相沉積氫化非晶矽膜作為矽晶鈍化層之研究,” 國立台灣科技大學, 2016.
[32]H. Fujiwara, Spectroscopic ellipsometry: principles and applications: John Wiley & Sons, 2007.
[33]R. M. Azzam, and N. M. Bashara, Ellipsometry and polarized light: North-Holland. sole distributors for the USA and Canada, Elsevier Science Publishing Co., Inc., 1987.
[34]D. Ewald, M. Milleville, and G. Weiser, “Optical spectra of glow-discharge-deposited silicon,” Philosophical Magazine B, vol. 40, no. 4, pp. 291-303, 1979.
[35]W. Jackson, S. Kelso, C. Tsai, J. Allen, and S.-J. Oh, “Energy dependence of the optical matrix element in hydrogenated amorphous and crystalline silicon,” Physical Review B, vol. 31, no. 8, pp. 5187, 1985.
[36]F. Wooten, Optical properties of solids: Academic press, 2013.
[37]G. Jellison Jr, and F. Modine, “Parameterization of the optical functions of amorphous materials in the interband region,” Applied Physics Letters, vol. 69, no. 3, pp. 371-373, 1996.
[38]A. Ferlauto, G. Ferreira, J. M. Pearce, C. Wronski, R. Collins, X. Deng, and G. Ganguly, “Analytical model for the optical functions of amorphous semiconductors from the near-infrared to ultraviolet: Applications in thin film photovoltaics,” Journal of Applied Physics, vol. 92, no. 5, pp. 2424-2436, 2002.
[39]A. Forouhi, and I. Bloomer, “Optical dispersion relations for amorphous semiconductors and amorphous dielectrics,” Physical review B, vol. 34, no. 10, pp. 7018, 1986.
[40]S. Adachi, Optical properties of crystalline and amorphous semiconductors: Materials and fundamental principles: Springer Science & Business Media, 2012.
[41]J. Leng, J. Opsal, H. Chu, M. Senko, and D. Aspnes, “Analytic representations of the dielectric functions of materials for device and structural modeling,” Thin Solid Films, vol. 313, pp. 132-136, 1998.
[42]H. Fujiwara, J. Koh, P. Rovira, and R. Collins, “Assessment of effective-medium theories in the analysis of nucleation and microscopic surface roughness evolution for semiconductor thin films,” Physical Review B, vol. 61, no. 16, pp. 10832, 2000.
[43]CompleteEASETM Data Analysis Manual: J. A. Woollam Co., Inc., 2011.
[44]E. Hecht, “Optics, 4th,” International edition, Addison-Wesley, San Francisco, vol. 3, 2002.
[45]J. C. Vickerman, and I. Gilmore, Surface analysis: the principal techniques: John Wiley & Sons, 2011.
[46]E. Bhattacharya, and A. Mahan, “Microstructure and the light‐induced metastability in hydrogenated amorphous silicon,” Applied physics letters, vol. 52, no. 19, pp. 1587-1589, 1988.
[47]C. Fang, K. Gruntz, L. Ley, M. Cardona, F. Demond, G. Müller, and S. Kalbitzer, “The hydrogen content of a-Ge: H and a-Si: H as determined by IR spectroscopy, gas evolution and nuclear reaction techniques,” Journal of Non-Crystalline Solids, vol. 35, pp. 255-260, 1980.
[48]A. Langford, M. Fleet, B. Nelson, W. Lanford, and N. Maley, “Infrared absorption strength and hydrogen content of hydrogenated amorphous silicon,” Physical Review B, vol. 45, no. 23, pp. 13367, 1992.
[49]N. Maley, “Critical investigation of the infrared-transmission-data analysis of hydrogenated amorphous silicon alloys,” Physical Review B, vol. 46, no. 4, pp. 2078, 1992.
[50]R. A. Sinton, and A. Cuevas, “Contactless determination of current–voltage characteristics and minority‐carrier lifetimes in semiconductors from quasi‐steady‐state photoconductance data,” Applied Physics Letters, vol. 69, no. 17, pp. 2510-2512, 1996.
[51]D. Macdonald, R. A. Sinton, and A. Cuevas, “On the use of a bias-light correction for trapping effects in photoconductance-based lifetime measurements of silicon,” Journal of Applied Physics, vol. 89, no. 5, pp. 2772-2778, 2001.
[52]吳佳盈, “以射頻電漿輔助化學氣相沉積法製備高效率矽晶異質接合太陽能電池之研究,” 國立台灣科技大學, 2011.
[53]T. Kuwahara, H. Ito, K. Kawaguchi, Y. Higuchi, N. Ozawa, and M. Kubo, “The reason why thin-film silicon grows layer by layer in plasma-enhanced chemical vapor deposition,” Scientific reports, vol. 5, 2015.
[54]T. H. Wang, E. Iwaniczko, M. R. Page, D. H. Levi, Y. Yan, H. M. Branz, and Q. Wang, “Effect of emitter deposition temperature on surface passivation in hot-wire chemical vapor deposited silicon heterojunction solar cells,” Thin Solid Films, vol. 501, no. 1–2, pp. 284-287, 4/20/, 2006.
[55]C. Koch, M. Ito, and M. Schubert, “Low-temperature deposition of amorphous silicon solar cells,” Solar Energy Materials and Solar Cells, vol. 68, no. 2, pp. 227-236, 2001/05/01/, 2001.
[56]A. Matsuda, and T. Goto, “Role of Surface and Growth-Zone Reactions in the Formation Process of µc-Si:H,” MRS Proceedings, vol. 164, 2011.
[57]A. M. Ali, “Mechanisms of the growth of nanocrystalline Si: H films deposited by PECVD,” Journal of non-crystalline solids, vol. 352, no. 28, pp. 3126-3133, 2006.
[58]H. Shirai, J.-i. Hanna, and I. Shimizu, “Role of atomic hydrogen during growth of hydrogenated amorphous silicon in the “chemical annealing”,” Japanese journal of applied physics, vol. 30, no. 4B, pp. L679, 1991.