Silisyum İnce Filmlerde Taban Malzemelerin Elektronik Kusurlar Üzerine Etkisinin Belirlenmesi

Yıl 2022, , 69 - 76, 25.04.2022

Gökhan Yılmaz

https://doi.org/10.19113/sdufenbed.946400

Öz

Silisyum ince filmlerin taban malzeme ve üretim koşullarına bağlı olarak kristal hacim oranları değişmektedir. Kristal hacim oranlarındaki bu farklılık ince filmlerin yasak enerji aralığında bulunun elektronik kusur çeşitlerini de etkilemektedir. Silisyum ince filmlerde atmosferik koşullardan ya da uzun süre ışığa maruz kalmalarından kaynaklı olarak elektronik kusurlar oluşmaktadır. Elektronik kusurların değişimine bağlı olarak iletkenlik değerlerinde değişimler oluşmaktadır. Bu çalışmada PECVD tekniği kullanılarak aynı anda üç farklı taban malzeme üzerine silisyum ince filmler büyütülmüştür. Büyütülen filmlerin kristal hacim oranları Raman Spektroskopisi ile yüzey morfolojileri ise taramalı elektron mikroskobu (SEM) yöntemi ile belirlenmiştir. Büyütülen silisyum ince filmler farklı atmosferik koşullara ( laboratuvar atmosferi, ışık banyosu ve UV ışık yaşlandırmasına) maruz bırakılarak bilinçli bir şekilde ince filmlerin yapısında elektronik kusurlar oluşturulmuştur. Bu kusurların davranışı elektriksel iletkenlik yöntemleri olan zamana bağlı karanlık iletkenlik, fotoiletkenlik ve mobilite-yaşam süresi hesaplamaları ile incelenmiştir. Elde edilen bulgular sonucunda taban malzemelerin farklı olmasından kaynaklı malzemelerin kristal hacim oranlarında ve kalınlıklarında belirgin farklılıklar oluştuğu ve bu farklılıklardan kaynaklı olarak malzemelerin aynı atmosferik koşullarda farklı elektronik kusur durumlarından etkilendikleri belirlenmiştir.

Anahtar Kelimeler

Silisyum ince film, PECVD, Elektronik kusurlar, Taban malzeme etkisi

Teşekkür

Bu çalışmada laboratuvar imkânlarını açtıklarından dolayı Jülich Araştırma Merkezine teşekkür ederim. Buna ek olarak akademik katkıları ve keyifli akademik sohbetleri için Dr. Friedhelm FINGER’a ve Dr. Vladimir SMIRNOV’a teşekkürü bir borç bilirim.

Determination of the Effect of Substrates on Electronic Defects in Silicon Thin Films

Öz

The crystal volume ratios of silicon thin films vary depending on the substrate material and production conditions. The difference in crystal volume fraction also affects the types of electronic defects in the band gap of thin films. Electronic defects occur in silicon thin films due to atmospheric conditions or prolonged light exposure. Conductivity values changes can occur due to the change of electronic defects. In this study, silicon thin films were grown on three different substrates at the same time using the PECVD technique. The crystal volume ratios and surface morphology of the grown films were determined by Raman Spectroscopy and scanning electron microscopy (SEM) respectively. The grown silicon thin films intentionally were exposed to different atmospheric conditions (such as laboratory atmosphere, light soaking and UV aging) and electronic defects were created in the structure of the thin films. The behavior of these defects were investigated by electrical conductivity methods, which are time dependent dark conductivity, photoconductivity and mobility-lifetime calculations. As a result of the findings, it was determined that there were significant differences in the crystal volume ratios and thicknesses of the materials due to the different base materials, and that the materials were affected by different electronic defect states in the same atmospheric conditions due to these differences.

Anahtar Kelimeler

Silicon thin film, PECVD, Electronic defects, Substrate effect

Kaynakça

• [1] Houben, L., Luysberg, M., Hapke, P., Carius, R., Finger, F., Wagner, H. 1998. Structural Properties Of Microcrystalline Silicon İn The Transition From Highly Crystalline To Amorphous Growth. Philos. Mag. A Phys. Condens. Matter, Struct. Defects Mech. Prop., 77 (6) 1447–1460.
• [2] Vetterl, O., Finger, F., Carius, R., Hapke, P., Houben, L., Kluth, O., Lambertz, A., Mück, A., Rech, B., Wagner, H. 2000. Intrinsic Microcrystalline Silicon: A New Material For Photovoltaics Sol. Energy Mater. Sol. Cells, 62 97–108.
• [3] Staebler, D, L., Wronski, C, R., 1977. Reversible Conductivity Changes İn Discharge-Produced Amorphous Si Appl. Phys. Lett., 31 292-294.
• [4] Güneş, M., Wronski, C, R., 1997. Differences İn The Densities Of Charged Defect States And Kinetics Of Staebler–Wronski Effect İn Undoped (Nonintrinsic) Hydrogenated Amorphous Silicon Thin Films J. Appl. Phys., 81 3526-3536.
• [5] Veprek, S., Iqbal, Z., Kuhne, R, O., Capezzuto, P., Sarott, F., Gimzewski, J, K. 1983. Properties of microcrystalline silicon. Iv. Electrical conductivity, electron spin resonance and the effect of gas adsorption J. Phys. C Solid State Phys., 16 6241–6262.
• [6] Stutzmann, M., Jackson, W., Tsai, C. 1985. Light-İnduced Metastable Defects İn Hydrogenated Amorphous Silicon: A Systematic Study Phys. Rev. B, 32 23–47
• [7] Kočka, J., Vaněček, M., Tříska, A. 1989. Energy And Densıty Of Gap States In a-Si:H. Amorphous Silicon and Related Materials vol A, 297–327.
• [8] Curtins, H., Favre, M. 1989. Surface And Bulk States Determıned By Photothermal Deflectıon Spectroscopy. Amorphous Silicon and Related Materials vol A, 329–363.
• [9] Street, R, A. 1991. Hydrogenated Amorphous Silicon. Cambridge: Cambridge University Press 417s.
• [10] Vaněček, M., Kočka, J., Poruba, A., Fejfar, A. 1995. Direct Measurement Of The Deep Defect Density İn Thin Amorphous Silicon Films With The ‘“Absolute”’ Constant Photocurrent Method J. Appl. Phys., 78 6203-6210.
• [11] Vaněček, M., Poruba, A., Remeš, Z., Beck, N., Nesládek, M. 1998. Optical Properties Of Microcrystalline Materials J. Non. Cryst. Solids, 227–230 967–972.
• [12] Vaněček, M., Poruba, A., Remeš, Z., Rosa, J., Kamba, S., Vorlı́ček, V., Meier, J., Shah, A. 2000. Electron Spin Resonance And Optical Characterization Of Defects İn Microcrystalline Silicon J. Non. Cryst. Solids, 266–269 519–523.
• [13] Günes, M., Cansever, H., Yilmaz, G., Smirnov, V., Finger, F., Brüggemann, R. 2012. Metastability Effects İn Hydrogenated Microcrystalline Silicon Thin Films İnvestigated By The Dual Beam Photoconductivity Method J. Non. Cryst. Solids 358 2074–2077.
• [14] Saleh, Z, M., Nogay, G., Ozkol, E., Yilmaz, G., Sagban, M., Gunes, M., Turan, R. 2014. Atmospheric Aging And Light-İnduced Degradation Of Amorphous And Nanostructured Silicon Using Photoconductivity And Electron Spin Resonance. Can. J. Phys. 92 713–717.
• [15] Yilmaz, G., Cansever, H., Sagban, H, M., Günes, M,, Smirnov, V., Finger, F., Brüggemann, R. 2014. Reversible And İrreversible Effects After Oxygen Exposure İn Thick (>1 Μm) Silicon Films Deposited By Vhf-Pecvd On Glass Substrates İnvestigated By Dual Beam Photoconductivity. Can. J. Phys. 92 778–782.
• [16] Güneş, M., Turan, E., Yilmaz, G. 2009. Investigation of Meta- and In-stability Effect in Thin Film Silicon Materials Using Intensity and Temperature Dependence of Photoconductivity. J. Optoelectron. Adv. M. symposia, vol. 1,202–205.
• [17] Yilmaz, G., Turan. E,, Günes, M., Smirnov, V., Finger, F., Brüggemann, R. 2010. Instability Effects İn Hydrogenated Microcrystalline Silicon Thin Films. Physica Status Solidi (C) Current Topics in Solid State Physics 7 (3-4), 700-703.
• [18] Dylla, T., Finger, F., Carius, R. 2003. Adsorption and Oxidation Effects in Microcrystalline Silicon. MRS Proc. 762 A2.5
• [19] Cansever, H., Günes, M., Yilmaz, G., Sagban, H, M., Smirnov, V., Finger, F., Brüggemann, R. 2014. Investigation Of Metastability And İnstability Effects On The Minority Carrier Transport Properties Of Microcrystalline Silicon Thin Films By Using The Steady-State Photocarrier Grating Technique. Can. J. Phys. 92 763–767.
• [20] Yilmaz, G., Cansever, H., Sagban, H, M., Günes, M., Smirnov, V., Finger, F., Brüggemann, R. 2014. Reversible And İrreversible Effects After Oxygen Exposure İn Thick (≫1 Μm) Silicon Films Deposited By Vhf-Pecvd On Glass Substrates İnvestigated By Dual Beam Photoconductivity. Can. J. Phys. 92, 778–782.
• [21] CANSEVER, H. 2012. Mikro Kristal Silisyum İnce Film Malzemelerde Yaşlandırma İşlemlerinin Malzemenin Optoelektronik Özelliklerine Etkisi Muğla Sıtkı Koçman Üniversitesi, Fen Bilimleri Enstitüsü, Yüksek Lisans Tezi, 142s, Muğla.
• [22] Turan, E., Yilmaz, G., Smirnov, V., Finger, F., Günes, M. 2012. Rapid Reversible Degradation Of Silicon Thin Films By A Treatment İn Water. Jpn. J. Appl. Phys. 51,070210-3p.
• [23] Astakhov, O., Carius, R., Petrusenko, Y., Borysenko, V., Barankov, D., Finger, F. 2012. The Relationship Between Hydrogen and Paramagnetic Defects in Thin Film Silicon Irradiated with 2 mev Electrons. J. Phys. Condens. Matter 24 305801 8p.
• [24] Persheyev, S, K., Smirnov, V., O’Neill, K, A., Reynolds, S., Rose, M, J. 2005. Atmospheric Adsorption Effects İn Hot-Wire Chemical-Vapor-Deposition Microcrystalline Silicon Films With Different Electrode Configurations. Semiconductors 39 343–346.
• [25] Souffi, N., Bauer, G, H., Brüggemann, R. 2006. Study Of Metastabilities İn Microcrystalline Silicon Films By Photoconductivity Techniques. Thin Solid Films 501 129–132.
• [26] Finger, F., Carius, R., Dylla, T., Klein, S., Okur, S., Günes, M. 2003. Stability of Microcrystalline Silicon for Thin Film Solar Cell Applications. IEE Proc. - Circuits, Devices Syst. 150 300-308.
• [27] Lim, T, H. 2014. New Findings and Interpretation on Atmospheric Adsorption Induced Instability in Microcrystalline Silicon Films Int. J. Mater. Sci. Appl. 3 100-105.
• [28] Phinikarides, A., Kindyni, N., Makrides, G., Georghiou, G, E. 2014. Review Of Photovoltaic Degradation Rate Methodologies Renew. Sustain. Energy Rev. 40 143–152.
• [29] Finger, F., Carius, R., Dylla, T., Klein, S., Okur, S., Günes, M. 2005. Instabılıty Phenomena In Mıcrocrystallıne Sılıcon Fılms J. Optoelectron. Adv. M. 7 83–90.
• [30] Müller, J., Finger, F., Carius, R., Wagner, H. 1999. Electron Spin Resonance İnvestigation Of Electronic States İn Hydrogenated Microcrystalline Silicon. Phys. Rev. B 60 11666–11677.
• [31] Signh. K., Mrutyunjay. N., Dipak. S. K., Vamsi. K.K. 2021. Degradation Study of Carrier Selective Contact Silicon Solar Cells with Ageing: Role of Silicon Surface Morphology. Solid State Electronics 179 107987.
• [32] Han. C. 2020. Analysis of Moisture Induced Degradation of Thin-film Photovoltaic Module. Sol. Energy Mater. Sol. Cells. 210. 110488
• [33] Elkhamisy, K.M., Abdelhamid, H., Elagooz, S., El-Rabaie, E. 2021. The Effect of Temperature Varience with Different Surface Shape on Efficiency of Silicon Thin Film Solar Cell. Opt.Quant.Electron. Underreview.
• [34] Bube R.H. 1960. Photoconductivity of Solids. JOHN WILEY & SONS Inc., NewYork-London 492s.