Hostname: page-component-7c8c6479df-27gpq Total loading time: 0 Render date: 2024-03-28T12:39:37.042Z Has data issue: false hasContentIssue false

Optical analysis of room temperature magnetron sputtered ITO films by reflectometry and spectroscopic ellipsometry

Published online by Cambridge University Press:  28 July 2014

Tivadar Lohner*
Affiliation:
Department of Photonics, Research Centre for Natural Sciences, Institute for Technical Physics and Materials Science, H-1121 Budapest, Hungary
K. Jagadeesh Kumar
Affiliation:
Semiconductor Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
Péter Petrik
Affiliation:
Department of Photonics, Research Centre for Natural Sciences, Institute for Technical Physics and Materials Science, H-1121 Budapest, Hungary; and Department of Nanotechnology, University of Pannonia, H-8200 Veszprém, Hungary
Aryasomayajula Subrahmanyam
Affiliation:
Semiconductor Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
István Bársony
Affiliation:
Research Centre for Natural Sciences, Institute for Technical Physics and Materials Science, H-1121 Budapest, Hungary; and Department of Nanotechnology, University of Pannonia, H-8200 Veszprém, Hungary
*
a)Address all correspondence to this author. e-mail: lohner@mfa.kfki.hu
Get access

Abstract

Indium-tin-oxide (ITO) thin films were prepared by reactive magnetron sputtering; their optical constants and thickness were determined by spectral reflectometry (SR) in the wavelength range from 400 nm to 800 nm and spectroscopic ellipsometry (SE) in the wavelength range from 191 nm to 1690 nm. A comparative evaluation of the measured data from SR and SE has been made using the same single layer optical model based on the Cauchy dispersion relation. The introduction of a surface roughness layer into the optical model considerably improved the fit quality during evaluation of SE data. Vertical inhomogeneity of the ITO thin films was assessed using a multilayer optical model describing porosity gradient and the three-layer optical model suggested by Jung [Y.S. Jung, Thin Solid Films467, 36 (2004)] from the SE data.

Type
Articles
Copyright
Copyright © Materials Research Society 2014 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Zheng, J.P. and Kwok, H.S.: Preparation of indium tin oxide films at room temperature by pulsed laser deposition. Thin Solid Films 232, 99 (1993).CrossRefGoogle Scholar
Fukarek, W. and Kersten, H.: Application of dynamic in situ ellipsometry to the deposition of tin-doped indium oxide films by reactive direct-current magnetron sputtering. J. Vac. Sci. Technol., A 12, 523 (1994).CrossRefGoogle Scholar
Woollam, J.A., McGahan, W.A., and Johs, B.: Spectroscopic ellipsometry studies of indium tin oxide and other flat panel display multilayer materials. Thin Solid Films 241, 44 (1994).CrossRefGoogle Scholar
Synowicki, R.A.: Spectroscopic ellipsometry characterization of indium tin oxide film microstructure and optical constants. Thin Solid Films 313/314, 394 (1998).CrossRefGoogle Scholar
Benamar, E., Rami, M., Messaoudi, C., Sayan, D., and Ennaoui, A.: Structural, optical and electrical properties of indium tin oxide thin films prepared by spray pyrolysis. Sol. Energy Mater. Sol. Cells 56, 125 (1999).CrossRefGoogle Scholar
Dobrowolski, J.A., Li, L., and Hilfiker, J.N.: Long-wavelength cutoff filters of a new type. Appl. Opt. 38, 4891 (1999).CrossRefGoogle ScholarPubMed
George, J. and Mourn, C.S.: Electrical and optical properties of electron beam evaporated ITO thin films. Surf. Coat. Technol. 132, 45 (2000).CrossRefGoogle Scholar
Han, Y., Kim, D., Cho, J.S., Koh, S.K., and Song, Y.S.: Tin-doped indium oxide (ITO) film deposition by ion beam sputtering. Sol. Energy Mater. Sol. Cells 65, 211 (2001).CrossRefGoogle Scholar
Martino, M., Luches, A., Fernandez, M., Anobile, P., and Petnizzelli, V.: Characterization of thin indium tin oxide films deposited by pulsed XeCl laser ablation. J. Phys. D: Appl. Phys. 34, 2606 (2001).CrossRefGoogle Scholar
Losurdo, M., Giangregorio, M., Capezzuto, P., Bruno, G., DeRosa, R., Roca, F., Summonte, C., Plá, J., and Rizzoli, R.: Parametrization of optical properties of indium–tin–oxide thin films by spectroscopic ellipsometry: Substrate interfacial reactivity. J. Vac. Sci. Technol., A 20, 37 (2002).CrossRefGoogle Scholar
El Rhaleb, H., Benamar, E., Rami, M., Roger, J.P., Hakam, A., and Ennaoui, A.: Spectroscopic ellipsometry studies of index profile of indium tin oxide films prepared by spray pyrolysis. Appl. Surf. Sci. 201, 138 (2002).CrossRefGoogle Scholar
Gorjanc, T.C., Lemig, D., Py, C., and Roth, D.: Room temperature deposition of ITO using r.f. magnetron sputtering. Thin Solid Films 413, 181 (2002).CrossRefGoogle Scholar
Maki, K., Komiya, N., and Suzuki, A.: Fabrication of thin films of ITO by aerosol CVD. Thin Solid Films 445, 224 (2003).CrossRefGoogle Scholar
Jung, Y.S.: Spectroscopic ellipsometry studies on the optical constants of indium tin oxide films deposited under various sputtering conditions. Thin Solid Films 467, 36 (2004).CrossRefGoogle Scholar
Yamaguchi, M., Ide-Ektessabi, A., Nomura, H., and Yasiu, N.: Characteristics of indium tin oxide thin films prepared using electron beam evaporation. Thin Solid Films 447/448, 115 (2004).CrossRefGoogle Scholar
Jung, Y.S.: A spectroscopic ellipsometry study on the variation of the optical constants of tin-doped indium oxide thin films during crystallization. Solid State Commun. 129, 491 (2004).CrossRefGoogle Scholar
Ngaffo, F.F., Caricato, A.P., Fazzi, A., Fernandez, M., Lattante, S., Martino, M., and Romano, F.: Deposition of ITO films on SiO2 substrates. Appl. Surf. Sci. 248, 428 (2005).CrossRefGoogle Scholar
Lee, H.C. and Park, O.O.: The evolution of the structural, electrical and optical properties in indium-tin-oxide thin film on glass substrate by DC reactive magnetron sputtering. Vacuum 80, 880 (2006).CrossRefGoogle Scholar
Krasilnikova Sytchkova, A., Grilli, M.L., Boycheva, S., and Piegari, A.: Optical, electrical, structural and microstructural characteristics of r.f. sputtered ITO films developed for art protection coating. Appl. Phys. A 89, 63 (2007).CrossRefGoogle Scholar
Kim, J.K., Chhajed, S., Schubert, M.F., Schubert, E.F., Fischer, A.J., Crawford, M.H., Cho, J., Kim, H., and Sone, C.: Light-extraction enhancement of GaInN light-emitting diodes by graded-refractive-index indium tin oxide anti-reflection contact. Adv. Mater. 20, 801 (2008).CrossRefGoogle Scholar
Hao, L., Diao, X., Xu, H., Gu, B., and Wang, T.: Thickness dependence of structural, electrical and optical properties of indium tin oxide (ITO) films deposited on PET substrates. Appl. Surf. Sci. 254, 3504 (2008).CrossRefGoogle Scholar
Sathiaraj, T.S.: Effect of annealing on the structural, optical and electrical properties of ITO films by RF sputtering under low vacuum level. Microelectron. J. 39, 1444 (2008).CrossRefGoogle Scholar
Iljinas, A., Mockevicius, I., Andrulevicius, M., Meskinis, S., and Tamulevicius, S.: Growth of ITO thin films by magnetron sputtering: OES study, optical and electrical properties. Vacuum 83, S118 (2009).CrossRefGoogle Scholar
Tejo-Cruz, C., Mendoza-Galván, A., López-Beltrán, A.M., and Garcia-Jimenez, M.: Effects of air annealing on the optical, electrical, and structural properties of indium-tin oxide thin films. Thin Solid Films 517, 4615 (2009).CrossRefGoogle Scholar
D'Elia, S., Scaramuzza, N., Ciuchi, F., Versace, C., Strangi, G., and Bartolino, R.: Ellipsometry investigation of the effects of annealing temperature on the optical properties of indium tin oxide thin films studied by Drude–Lorentz model. Appl. Surf. Sci. 255, 7203 (2009).CrossRefGoogle Scholar
Senthilkumar, V., Vickraman, P., Jayachandran, M., and Sanjeeviraja, C.: Structural and optical properties of indium tin oxide (ITO) thin films with different compositions prepared by electron beam evaporation. Vacuum 84, 864 (2010).CrossRefGoogle Scholar
Kumar, K.J., Raju, N.R.C., and Subrahmanyam, A.: Thickness dependent physical and photocatalytic properties of ITO thin films prepared by reactive DC magnetron sputtering. Appl. Surf. Sci. 257, 3075 (2011).CrossRefGoogle Scholar
Kim, H., Pique, A., Horowitz, J.S., Mattoussi, H., Murata, H., Kafafi, Z.H., and Chrisey, D.B.: Indium tin oxide thin films for organic light-emitting devices. Appl. Phys. Lett. 74, 3444 (1999).CrossRefGoogle Scholar
Teixeira, V., Cui, H.N., Meng, L.J., Fortunato, E., and Martins, R.: Amorphous ITO thin films prepared by DC sputtering for electrochromic applications. Thin Solid Films 420, 70 (2002).CrossRefGoogle Scholar
Chu, J.B., Huang, S.M., Zhu, H.B., Xu, X.B., Sun, Z., Chen, Y.W., and Huang, F.Q.: Preparation of indium tin oxide thin films without external heating for application in solar cells. J. Non-Cryst. Solids 354, 5480 (2008).CrossRefGoogle Scholar
Lobl, H.P., Huppertz, M., and Mergel, D.: ITO films for antireflective and antistatic tube coatings prepared by d.c. magnetron sputtering. Surf. Coat. Technol. 82, 90 (1996).CrossRefGoogle Scholar
Sako, T., Ohmi, A., Yumoto, H., and Nishiyama, K.: ITO-film gas sensor for measuring photodecomposition of NO2 gas. Surf. Coat. Technol. 142/144, 781 (2001).CrossRefGoogle Scholar
Balestrieri, M., Pysch, D., Becker, J-P., Hermle, M., Warta, W., and Glunz, S.W.: Characterization and optimization of indium tin oxide films for hetero junction solar cells. Sol. Energy Mater. Sol. Cells 95, 2390 (2011).CrossRefGoogle Scholar
Irene, E.A.: Applications of spectroscopic ellipsometry to microelectronics. Thin Solid Films 233, 96 (1993).CrossRefGoogle Scholar
Stoica, T.F., Gartner, M., Losurdo, M., Teodorescu, V., Blanchin, M., Stoica, T., and Zaharescu, M.: Spectroellipsometric study of the sol–gel nanocrystalline ITO multilayer films. Thin Solid Films 455/456, 509 (2004).CrossRefGoogle Scholar
Fujiwara, H.: Spectroscopic Ellipsometry: Principles and Applications (John Wiley and Sons, Chichester, England, 2007).CrossRefGoogle Scholar
Major, C., Juhász, G., Horváth, Z., Polgár, O., and Fried, M.: Wide angle beam ellipsometry for extremely large samples. Phys. Status Solidi C 5(5), 1077 (2008).CrossRefGoogle Scholar
Kulik, M., Zuk, J., Drozdiel, A., Pyszniak, K., Komarov, F.F., and Rzodkiewicz, W.: RBS-C and ellipsometric investigations of radiation damage in hot-implanted GaAs layers. Mater. Sci. Eng., B 176, 340 (2011).CrossRefGoogle Scholar
www.filmetrics.com (accessed June 2014).Google Scholar
J.A. Woollam Co., Inc.: www.jawoollam.com (accessed March 2014).Google Scholar
Aspnes, D.E.: Optical properties of thin films. Thin Solid Films 89, 249 (1982).CrossRefGoogle Scholar
Tseng, K-S. and Lo, Y-L.: Investigation into inhomogeneous electrical and optical properties of indium tin oxide film using spectroscopic ellipsometry with multi-layer optical models. Opt. Mater. Express 4, 43 (2014).CrossRefGoogle Scholar