Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-10T08:23:16.015Z Has data issue: false hasContentIssue false
  • English
  • Français

Influence of the Microstructure on the Optical Characteristics of SrTiO3 thin films

Published online by Cambridge University Press:  03 March 2011

M. Gaidi ,
L. Stafford ,
A. Amassian ,
M. Chaker ,
J. Margot ,
L. Martinu  and
M. Kulishov
M. Gaidi*
Affiliation:
Institut National de la Recherche Scientifique Énergie, Matériaux et Télécommunications, Varennes, Québec J3X 1S2, Canada
L. Stafford
Affiliation:
Université de Montréal, Département de Physique, Montréal, Québec H3C 3J7, Canada
A. Amassian
Affiliation:
École Polytechnique de Montréal, Département de Génie Physique, Montréal, Québec H3C 3A7, Canada
M. Chaker
Affiliation:
Institut National de la Recherche Scientifique Énergie, Matériaux et Télécommunications, Varennes, Québec J3X 1S2, Canada
J. Margot
Affiliation:
Université de Montréal, Département de Physique, Montréal, Québec H3C 3J7, Canada
L. Martinu
Affiliation:
École Polytechnique de Montréal, Département de Génie Physique, Montréal, Québec H3C 3A7, Canada
M. Kulishov
Affiliation:
Adtek Photomask Inc, Montréal, Québec H4T 1J6, Canada
*
a)Address all correspondence to this author. e-mail: kaidi@inrs-emt.uquebec.ca
Get access

Abstract

The influence of the microstructure of strontium-titanate-oxide (SrTiO3 or STO) thin films on their optical properties was investigated through an extensive characterization. The STO films have been deposited on silicon substrates by reactive pulsed laser deposition. The effect of the oxygen deposition pressure on the crystalline quality of the films was systematically studied by x-ray diffraction and scanning electron microscopy. Rutherford backscattering spectrometry, x-ray photoelectron spectroscopy, and secondary ion mass spectrometry were used to determine the atomic density and depth concentration profiles of the various species forming the film. The refractive index and extinction coefficient were obtained using variable angle spectroscopic ellipsometry. Based on this full characterization, it is demonstrated that the optical characteristics of the films are directly correlated to their microstructural properties. In particular, the refractive index increases with film density, while losses decrease. In addition, the interface between STO and Si is characterized by an interdiffusion layer. As the deposition pressure is enhanced, the width of this layer significantly increases, inducing localized inhomogeneity of the refractive index.

Keywords

MicrostructurePulsed laser deposition (PLD)Optical properties
Type
Articles
Information
Journal of Materials Research , Volume 20 , Issue 1 , January 2005 , pp. 68 - 74
Copyright
Copyright © Materials Research Society 2004

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

1Joshi, P.C. and Krupanidhi, S.B.: Structural and electrical characteristics of SrTiO3 thin films for dynamic random access memory applications. J. Appl. Phys. 73, 7627 (1993).CrossRefGoogle Scholar
2Menesklou, W., Schreiner, H-J., Härdtl, K.H. and Ivers-Tiffée, E.: High temperature oxygen sensors based on doped SrTiO3. Sens. Actuators B 59, 184 (1999).CrossRefGoogle Scholar
3Sanchez, F., Varela, M., Queralt, X., Aguiar, R. and Morenza, J.L.: Preparation of SrTiO3 thin films on Si(100) substrates by laser ablation: Application as buffer layer for YBa2Cu3O7 films. Appl. Phys. Lett. 61, 2228 (1992).CrossRefGoogle Scholar
4Wu, X.D., Dijkkamp, D., Ogale, S.B., Inam, A., Chase, E.W., Miceli, P.F., Chang, C.C., Tarascon, J.M. and Venkatesan, T.: Epitaxial ordering of oxide superconductor thin films on (100) SrTiO3 prepared by pulsed laser evaporation. Appl. Phys. Lett. 51, 861 (1987).CrossRefGoogle Scholar
5Chu, C.W., Hor, P.H., Meng, R.L., Gao, L., Huang, Z.J. and Wang, Y.Q.: Evidence for superconductivity above 40 K in the La-Ba-Cu-O compound system. Phys. Rev. Lett. 58, 405 (1987).CrossRefGoogle ScholarPubMed
6Nam, S.H. and Kim, H.G.: The effect of heat treatment on the SrTiO3 thin films prepared by radio frequency magnetron sputtering. J. Appl. Phys. 72, 2895 (1992).CrossRefGoogle Scholar
7Rao, G.M. and Krupanidhi, S.B.: Study of electrical properties of pulsed excimer laser deposited strontium titanate films. J. Appl. Phys. 75, 2604 (1994).CrossRefGoogle Scholar
8Yeh, M.H., Liu, K.S. and Lin, I.N.: Structure and dielectric properties of SrTiO3 films prepared by a pulsed laser deposition technique. Jpn. J. Appl. Phys. 34, 2447 (1995).CrossRefGoogle Scholar
9Yamamichi, S., Sakuma, T., Takemura, K. and Miyasaka, Y.: SrTiO3 thin film preparation by ion beam sputtering and its dielectric properties. Jpn. J. Appl. Phys. 30, 2193 (1991).Google Scholar
10Shibuya, M., Nishitsuji, M., Kitagawa, M., Kamada, T., Hayashi, S., Tamura, A. and Hirao, T.: Substrate potential effects on low-temperature preparation of SrTiO3 thin films by rf magnetron sputtering. Jpn. J. Appl. Phys. 32 L1830 (1993).CrossRefGoogle Scholar
11Wang, Z., Kugler, V., Helmersson, U., Konofaos, N., Evangelou, E.K., Nakao, S. and Jin, P.: Electrical properties of SrTiO3 thin films on Si deposited by magnetron sputtering at low temperature. Appl. Phys. Lett. 79, 1513 (2001).Google Scholar
12Kalyanaraman, R., Vispute, R.D., Oktyabrsky, S., Dovidenko, K., Jagannadham, K., Narayan, J., Budai, J.D., Parikh, N. and Suvkhanov, A.: Influence of oxygen background pressure on crystalline quality of SrTiO3 films grown on MgO by pulsed laser deposition. Appl. Phys. Lett. 71, 1709 (1997).CrossRefGoogle Scholar
13Hiratani, M., Tarutani, Y., Fukazawa, T., Okamoto, M. and Takagi, K.: Growth of SrTiO3 thin films by pulsed-laser deposition. Thin Solid Films 227, 100 (1993).CrossRefGoogle Scholar
14Hiratani, M., Imagawa, K. and Takagi, K.: Orientation and crystal structure of SrTiO3 thin films prepared by pulsed-laser deposition. Jpn. J. Appl. Phys. 34, 254 (1995).Google Scholar
15Ahmet, P., Koida, T., Takakura, M., Nakajima, K., Yoshimoto, M., Koinuma, H., Tanaka, M., Takeguchi, M. and Chikow, T.: Diffusion induced amorphization in the crystalline SrTiO3 thin films grown on Si (100) investigated by combinatorial method. Appl. Surf. Sci. 189, 307 (2002).CrossRefGoogle Scholar
16Zollner, S., Demkov, A.A., Liu, R., Fejes, P.L., Gregory, R.B., Alluri, P., Curless, J.A., Yu, Z., Ramdani, J., Droopad, R., Tiwald, T.E., Hilfiker, J.N. and Wollam, J.A.: Optical properties of bulk and thin-film SrTiO3 on Si and Pt. J. Vac. Sci. Technol. B. 18, 2242 (2000).Google Scholar
17Wöhlecke, M., Marrello, V. and Onton, A.: Refractive index of BaTiO3 and SrTiO3 films. J. Appl. Phys. 48, 1748 (1977).CrossRefGoogle Scholar
18Khakani, M.A. El, Chaker, M. and Gat, E.: Pulsed laser deposition of highly conductive iridium oxide thin films. Appl. Phys. Lett. 69, 2027 (1996).Google Scholar
19Woolam, J.A.: Ellipsometric analysis of plasma deposited and plasma etched materials, in Plasma Processing of Semiconductors , NATO ASI Series Vol. 336, edited Williams, P.F.,(Kluwer, New York, 1997), p. 375.CrossRefGoogle Scholar
20Guinier, A.: Theory and Techniques of Radiocrystallography , 3rd ed.(Dunod, Paris, France, 1964), p. 462.Google Scholar
21Cheng, H.F., Yeh, M.H., Liu, K.S. and Lin, I.N.: Characteristics of BaTiO3 films prepared by pulsed laser deposition. Jpn. J. Appl. Phys. 32, 5656 (1993).CrossRefGoogle Scholar
22Doolittle, L.R.: A semiautomatic algorithm for rutherford backscattering analysis. Nucl. Instr. Meth. B. 15, 227 (1986).CrossRefGoogle Scholar
23Kim, Y.J. and Kim, H.J.: Trapped oxygen in the grain boundaries of ZnO polycrystalline thin films prepared by plasma-enhanced chemical vapor deposition. Mater. Lett. 41, 159 (1999).CrossRefGoogle Scholar
24Park, K.C., Kim, K.B., Raaijmakers, I.J.M. and Ngan, K.: The effect of density and microstructure on the performance of TiN barrier films in Cu metallization. J. Appl. Phys. 80, 5674 (1996).CrossRefGoogle Scholar
25Amassian, A. and Martinu, L.: École Polytechnique, Département de gènie physique (2004) private communication.Google Scholar
26Modine, G.E. Jellison Jr.and F.A.: Parameterization of the optical functions of amorphous materials in the interband region. Appl. Phys. Lett. 69, 371 (1996).Google Scholar