Study of low temperature poly silicon for solar cellsAdvisor: Dr.Hon KuanStudent: Tsung-Yu LiDate98/04/22

OutlineIntroduction

Experimental

Results and discussion

Conclusions

References

Introduction500C 1 X XRDSi FE-SEM-

Experimental

PART I AlPART II Al

Results and discussion(a) SiO2 film (200nm) (b) Al film(250nm) (c) a-Si film(250nm)

SEM

Results and discussionSEM

Results and discussionXRDRaman

Results and discussionfirst step annealing process at 500C for 1 hourwithout Al etching off

Results and discussionfirst step annealing process at 500C for 1 hour and Al etching off

Results and discussionXRD spectra of poly-Si thin film annealed at 500C for 1 hour and Al etched off

Results and discussionXRD spectra of Part I specimens annealed at (a) 450 C, and (b)500 C and 5 different durations and Al etched off

Results and discussionXRD peak intensity plot versus different annealing duration of Part I specimens annealed at 450 C, and 500 C

Results and discussionXRD FWHM plot versus different annealing duration of Part I specimens annealed at 450 C, and 500 C

Results and discussionCrystal size of polycrystalline silicon thin film versus different annealing duration of Part I specimens annealed at 450 C, and 500 CDK=1 X 2

Results and discussionXRD spectra of Part II specimens annealed at (a) 450 C, and (b)500 C and 5 different durations and Al etched off

Results and discussionXRD peak intensity plot versus different annealing duration of Part II specimens annealed at 450 C, and 500 C

Results and discussionXRD FWHM plot versus different annealing duration of Part II specimens annealed at 450 C, and 500 C

Results and discussionCrystal size of polycrystalline silicon thin film versus different annealing duration of Part II specimens annealed at 450 C, and 500 C

Results and discussionRaman spectra of single crystalline silicon111Widenborg[37]Raman 520 cm-1

JIN [38]Si-Si Raman 499 cm-1

Results and discussionRaman spectra of part I specimens under 5 different annealingdurations and annealing duration of (a) 450C, and (b) 500 C,and Al etched off

Results and discussionRaman spectra of part II specimens under 5 different annealingdurations and annealing duration of (a) 450C, and (b) 500 C,and Al etched off

Results and discussionSEM photos of part I specimens with the second step annealing process at 450C for (a)15 ,(b)30, (c)60,(d)120, and (e)240 minutes.

Results and discussionSEM photos of part I specimens with the second step annealing process at 500C for (a)15 ,(b)30, (c)60,(d)120, and (e)240 minutes.

Results and discussionpart I specimens with the second step annealing process at 450C for (a)15, (b)30, (c)60, (d)120,and (e)240 minutes.

Results and discussionpart I specimens with the Second step annealing process at 500C for (a)15, (b)30, (c)60, (d)120, and (e)240 minutes.

Results and discussionSEM photos of part II specimens with the second step annealing process at 450C for (a)15 ,(b)30, (c)60,(d)120, and (e)240 minutes.

Results and discussionSEM photos of part II specimens with the second step annealing process at 500C for (a)15 ,(b)30, (c)60,(d)120, and (e)240 minutes.

Results and discussionpart II specimens with the second step annealing process at 450C for (a)15, (b)30, (c)60, (d)120, and (e)240 minutes.

Results and discussionpart II specimens with the second step annealing process at 500C for (a)15, (b)30, (c)60, (d)120, and (e)240 minutes.

Results and discussionLeakage current variation of part I specimens versus bias voltage under 5 different annealing durations and annealing temperature of (a) 450 C and (b) 500C

Results and discussionLeakage current variation of part II specimens versus bias voltage under 5 different annealing durations and annealing temperature of (a) 450 C and (b) 500C

Results and discussionResistivity variations of part I and part II specimens versus bias voltage under 5 different annealing durations and annealing temperature of (a) 450 C and (b) 500C

Results and discussionMobility of poly-silicon thin film of part I and part II specimens as a function of annealing duration

Results and discussionCarrier concentration of poly-silicon thin film of part I and part IIspecimens as a function of annealing duration

Conclusions450 C 15 1m 3~5 m

15 60

a-Si1m

10-7 A/cm2103~106 -cm 500 C 30 23.4 cm2/V.s10-9 A/cm2 108 - cm

References[1] A. Wohllebe, R. Carius, L. Houben, A. Klatt, P. Hapke, J. Klomfa, H. Wagner, Crystallization of amorphous Si films for thin film silicon solar cells, Journal of Non-Crystalline Solids, 227-230, 1998, pp.925-929.[2] -2005.9 [3] http://www.e-tonsolar.com/edu.htm#1[4] H. Kim, G. Lee, D. Kim, S. H. Lee, A study of polycrystalline silicon thin films as a seed layer in liquid phase epitaxy using aluminum-induced crystallization, Current Applied Physics 2 (2002) pp.129-133[5] G. R. Hu, Y. S. Wu, C. W. Chao and H. C. Shih, Growth Mechanism of Laser Annealing of Nickel-Induced Lateral Crystallized Silicon Films, Jan. J. Appl. Phys., Vol. 45, No. 1A, 2006, pp.21-27[6] O. Nast, S. Brehme, D. H. Neuhaus, and S. R. Wenham, Senior Member, Polycrystalline Silicon Thin Films on Glass by Aluminum-Induced Crystallization, IEEE transactions on electron devices, VOL. 46, NO. 10, 1999.10[7] J.L. Hwang, F.Y. Yeh, Application and Lamination of Photovoltaic Module, , 230, 2006.2[8] W. D. Callister, Meterials Science and Engineering, John Wiley & Sons, Inc., Second Edition[9] 2002.9 103[10] W. Shockley, Electrons and Holes in semiconductors, Litton Edacation Publishing Co., Inc., 1950.[11] I. W. Wu, T. Y. Huang, W. B. Jackson, A. G. Lewis, and A. Chiang, Passivation Kinetics of Two Types of Defects in Polysilicon TFT by Plasma Hydrogenation, IEEE Electron Devices Lett., Vol. 12,1991, pp.181.[12] 1962003.4[13] T. Ohzone, M. Fukumoto, G. Fuse, A. Shinohara, S. Odanaka, and masaru sasago, ion-implanted Thin Polycrystalline-Silicon High-Value Resistors for High-Density Poly-Load Static RAM Applications , IEEE Trans. Electron Devices, Vol. 32, 1985, pp.1749.[14] D. B. Meakin, P. A. Coxon, P. Migliorato, J. Stoemenos, and N. A. Economou, High-performance thin-film transistors from optimized polycrystalline silicon films, Appl. Phys. Lett. Vol. 50, 1987, pp.1894.[15] K. Goshima, H. Toyoda, T. Kojima, M. Nishitani, M. Kitagawa, H. Yamazoe and H. Sugai, Lower Temperature Deposition of Polycrystalline Silicon Films from a Modified Inductively Coupled Silane Plasma Jan. J. Appl. Phys. Vol. 38, NO. 6A, 1999, pp.3655.

References[16] O. Ebil, R. Aparicio, S. Hazra, R. W. Birkmir, E. Sutterb, Deposition and structural characterization of poly-Si thin films on Al coated glass substrates using hot-wire chemical vapor deposition, Thin Solid Films 4302003, pp.120-124. 104[17] D. D. Sala, S. Loreti, L. Fornarini, I. Menicucci, A. Santoni, P. D. Veneri, C. Privatoc, J. Lancockd, Laser-assisted chemical vapor deposition of thick poly-Si layers for solar cells, Thin Solid Films 403-4042002, pp.302-306.[18] LTPS 2004.9 [19] M. S. Haque, H. A. Naseem, and W. D. Brown, Interaction of aluminum with hydrogenated amorphous silicon at low temperatures, J. Appl. Phys., Vol. 75, No. 8, 15 April 1994.[20] VLSI 2003.7.20 [21] O. Nast, Influence of interface and Al structure on layer exchange during aluminum-induced crystallization of amorphous silicon, J. Appl. Phys. Vol. 88, No. 2, 15 July 2000.[22] K. M. Lim, M. Y. Sung, Low noise digital data driver circuit integrated poly-Si TFT-LCD, Microelectronics Journal 30 (1999), pp.905-910.[23] E. V. Jelenkovic, K. Y. Tonga, W. Y. Cheungb, I. H. Wilsonb, S. P. Wongb, M. C. Poon, Low temperature doping of poly-SiGe films with boron by co-sputtering, Thin Solid Films 368 (2000) 55-60.[24] K. Naeli, Mat. Res. Soc. Symp. Proc. Vol. 664, (2001), A6.[25] S. Nakahara, Recent development in a TEM specimen preparation technique using FIB for semiconductor devices, Surface and Coatings Technology 169-170 (2003), pp.721-727.[26] J. K. Rath, Low temperature polycrystalline silicona review on deposition, physical properties and solar cell applications, Solar Energy Materials & Solar Cells (2003), pp.431-487. 105[27] 2005.7[28] 2000.12 [29] K. Nakamura, M. A. Nicolet, and J. W. Mayer, Interaction of Al layers with polycrystalline Si, Journal of Applied Physics, Vol. 46, No. 11, Noverber 1975.

References[30] O. Nast, Influence of interface and Al structure on layer exchange during aluminum-induced crystallization of amorphous silicon, J. Appl. Phys. Vol. 88, No. 2, 15 July 2000.[31] O. Nast, T. Puzzer, L. M. Koschier, A. B. Sproul, and Stuart R. Wenham, Aluminum-induced crystallization of amorphous silicon on glass substrates above and below the eutectic temperature, Appl. Phys. Lett. 73, No. 22, 30 November 1998.[32] M. S. Haque, H. A. Naseem, and W. D. Brown, Aluminum-induced crystallization and counter-doping of phosphorousdoped hydrogenated amorphous silicon at low temperatures, J. Appl. Phys. 79 (10), 15 May 1996[33] O. Prache, Active matrix molecular OLED microdisplays, Displays 22 (2001), pp.49-56.[34] W. S. Liao and S. C. Lee, Interfacial interaction between Al-1%Si and phosphorus-doped hydrogenated amorphous Si alloy at low temperature, J. Appl. Phys. 81 (12), 15 June 1997[35] E. Pihana, A. Slaouia, P. R. Cabarrocasb, A. Focsaa, Polycrystalline silicon films by aluminium-induced crystallisation: growth process vs. silicon deposition method, E. Pihan et al. / Thin Solid Films 451 452 (2004), pp.328-333 106[36] E. Pihan, A. Slaoui, A. Focsa, P. R. Cabarrocas, Polycrystalline silicon films on ceramic substrates by aluminium-induced crystallisation process, 3rd World Conference on Photovoltaic Energy Conversion, May 11-18, 2003 Osaka, Japan[37] P. I. Widenborg, A. G. Aberle, Surface morphology of poly-Si films made by aluminium-induced crystallisation on glass substrates, Journal of Crystal Growth 242 (2002), pp.270-282.[38] Z. JIN, G. A. Bhat, M. Yeungh, H. S. Kwok and M. Wong, Solid-Phase Reaction of Ni with Amorphous SiGe Thin Film on SiO2, Jpn. J. Appl. Phys., Vol. 36 (1997), pp. L 1637-L 1640.