Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-25T02:32:07.988Z Has data issue: false hasContentIssue false

Effect of film thickness on the structural and electrical properties of Ga-doped ZnO thin films prepared on glass and Al2O3 (0001) substrates by RF magnetron sputtering method

Published online by Cambridge University Press:  26 July 2012

S.M. Pawar
Affiliation:
Department of Materials Science and Engineering, Chonnam National University Puk-Gu, Gwangju 500-757, South Korea
Tae-Won Kim
Affiliation:
Honam Technology Service Division National Center for Nanoprocess and Equipments, Korea Institute of Industrial Technology, Gwangju 500-480, South Korea
Jin Hyeok Kim*
Affiliation:
Department of Materials Science and Engineering, Chonnam National University Puk-Gu, Gwangju 500-757, South Korea
*
a) Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

Thin films of Ga-doped ZnO (GZO) were prepared on glass and Al2O3 (0001) substrates by using RF magnetron sputtering at a substrate temperature of 350 °C, RF power of 175 W, and working pressure of 6 mTorr. The effect of film thickness and substrate type on the structural and electrical properties of the thin films was investigated. X-ray diffraction study showed that GZO thin films on glass substrates were grown as a polycrystalline hexagonal wurtzite phase with a c-axis preferred, out-of-plane orientation and random in-plane orientation. However, GZO thin films on Al2O3 (0001) substrates were epitaxially grown with an orientation relationship of . The structural images from scanning electron microscopy and atomic force microscopy showed that the GZO thin films on glass substrates had a rougher surface morphology than those on Al2O3 (0001) substrates. The electrical resistivity of 1000 nm-thick GZO thin films grown on glass and Al2O3 (0001) substrates was 3.04 × 10−4 Ωcm and 1.50 × 10−4 Ωcm, respectively. It was also found that the electrical resistivity difference between the films on the two substrates decreased from 9.48 × 10−4 Ωcm to 1.45 × 10−4 Ωcm with increasing the film thickness from 100 nm to 1000 nm.

Type
Articles
Copyright
Copyright © Materials Research Society 2009

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

1.Assuncao, V., Fortunato, E., Marques, A., Aguas, H., Ferreira, I., Costa, M.E.V., Martins, R.: Influence of the deposition pressure on the properties of transparent and conductive ZnO:Ga thin-film produced by r.f. sputtering at room temperature. Thin Solid Films 427, 401 (2003)CrossRefGoogle Scholar
2.Bhosle, V., Tiwari, A., Narayan, J.: Electrical properties of transparent and conducting Ga doped ZnO. J. Appl. Phys. 100, 033713 (2006)Google Scholar
3.You, Y.Z., Kim, Y.S., Choi, D.H., Jang, H.S., Lee, J.H., Kim, D.: Electrical and optical study of ITO films on glass and polymer substrates prepared by DC magnetron sputtering type negative metal ion beam deposition. Mater. Chem. Phys. 107, 444 (2008)CrossRefGoogle Scholar
4.Snure, M., Tiwari, A.: Structural, electrical, and optical characterizations of epitaxial Zn1−xGaxO films grown on sapphire (0001) substrate. J. Appl. Phys. 101, 124912 (2007)CrossRefGoogle Scholar
5.Ahn, B.D., Oh, S.H., Lee, C.H., Kim, G.H., Kim, H.J., Lee, S.Y.: Influence of thermal annealing ambient on Ga-doped ZnO thin films. J. Cryst. Growth 309, 128 (2007)Google Scholar
6.Yu, X.H., Ma, J., Ji, F., Wang, Y.H., Zhang, X.J., Cheng, C.F., Ma, H.L.: Preparation and properties of ZnO:Ga films prepared by r.f. magnetron sputtering at low temperature. Appl. Surf. Sci. 239, 222 (2005)CrossRefGoogle Scholar
7.Chen, X.L., Xu, B.H., Xue, J.M., Zhao, Y., Wei, C.C., Sun, J., Wang, Y., Zhang, X.D., Geng, X.H.: Boron-doped zinc oxide thin films for large-area solar cells grown by metal organic chemical vapor deposition. Thin Solid Films 515, 3753 (2007)CrossRefGoogle Scholar
8.Abduev, A.K., Akhmedov, A.K., Asvarov, A.S.: The structural and electrical properties of Ga doped ZnO and Ga, B-codoped ZnO thin films: The effects of additional boron impurity. Sol. Energy Mater. Sol. Cells 91, 258 (2007)CrossRefGoogle Scholar
9.Lin, L.Y., Jeong, M.C., Kim, D.E., Myoung, J.M.: Micro/nanomechanical properties of aluminum-doped zinc oxide films prepared by radio frequency magnetron sputtering. Surf. Coat. Technol. 201, 2547 (2006)CrossRefGoogle Scholar
10.Guillen, C., Herrero, J.: High conductivity and transparent ZnO:Al films prepared at low temperature by DC and MF magnetron sputtering. Thin Solid Films 515, 640 (2006)Google Scholar
11.Ma, J., Yu, X.H., Ji, F., Wang, Y.H., Zhang, X.J., Cheng, C.F., Ma, H.L.: Influence of vacuum annealing on properties of ZnO:Ga films prepared by r.f. magnetron sputtering. Rare Metal Mater. Eng. 34, 1166 (2005)Google Scholar
12.Kim, S., Lee, W.I., Lee, E.H., Hwang, S.K., Lee, C.: Dependence of the resistivity and the transmittance of sputter-deposited Ga-doped ZnO films on oxygen partial pressure and sputtering temperature. J. Mater. Sci. 42, 4845 (2007)CrossRefGoogle Scholar
13.Ma, Q.B., Ye, Z.Z., He, H.P., Hu, S.H., Wang, J.R., Zhu, L.P., Zhang, Y.Z., Zhao, B.H.: Structural, electrical, and optical properties of transparent conductive ZnO:Ga films prepared by DC reactive magnetron sputtering. J. Cryst. Growth 304, 64 (2007)CrossRefGoogle Scholar
14.Fortunato, E., Assuncao, V., Marques, A., Goncalves, A., Aguas, H., Pereira, L., Ferreira, I., Fernandes, F.M.B., Silva, R.J.C., Martins, R.: ZnO:Ga thin films produced by RF sputtering at room temperature: Effect of the power density. Mater. Sci. Forum 455-456, 12 (2004)CrossRefGoogle Scholar
15.Ataev, B.M., Bagamadova, A.M., Djabrailov, A.M., Mamedov, V.V., Rabadanov, R.A.: Highly conductive and transparent Ga-doped epitaxial ZnO films on sapphire by CVD. Thin Solid Films 260, 19 (1995)CrossRefGoogle Scholar
16.Cheong, K.Y., Muti, N., Ramanan, S.R.: Electrical and optical studies of ZnO:Ga thin films fabricated via the sol-gel technique. Thin Solid Films 410, 142 (2002)CrossRefGoogle Scholar
17.Park, S-M., Ikegami, T., Ebihara, K.: Effects of substrate temperature on the properties of Ga-doped ZnO by pulsed laser deposition. Thin Solid Films 513, 90 (2006)CrossRefGoogle Scholar
18.Kato, H., Sano, M., Miyamoto, K., Yao, T.: Growth and characterization of Ga-doped ZnO layers on a-plane sapphire substrates grown by molecular beam epitaxy. J. Cryst. Growth 237-239, 538 (2002)Google Scholar
19.Yamada, T., Nebiki, T., Kishimoto, S., Makino, H., Awai, K., Narusawa, T., Yamamoto, T.: Dependences of structural and electrical properties on thickness of polycrystalline Ga-doped ZnO thin films prepared by reactive plasma deposition. Superlattices Microstruct. 42, 68 (2007)Google Scholar
20.Kim, S., Jeon, J., Kim, H.W., Lee, J.G., Lee, C.: Influence of substrate temperature and oxygen/argon flow ratio on the electrical and optical properties of Ga-doped ZnO thin films prepared by RF magnetron sputtering. Cryst. Res. Technol. 41, 1194 (2006)CrossRefGoogle Scholar
21.Christoulakis, S., Suchea, M., Koudoumas, E., Katharakis, M., Katsarakis, N., Kiriakidis, G.: Thickness influence on surface morphology and ozone sensing properties of nanostructured ZnO transparent thin films grown by PLD. Appl. Surf. Sci. 252, 5351 (2006)Google Scholar
22.Liu, Z.F., Shan, F.K., Li, Y.X., Shin, B.C., Yu, Y.S.: Epitaxial growth and properties of Ga-doped ZnO films grown by pulsed laser deposition. J. Cryst. Growth 259, 130 (2003)Google Scholar
23.Kim, T.H., Jeong, S.H., Kim, I.-S., Kim, S.S., Lee, B.-T.: Magnetron sputtering growth and characterization of high quality single crystal Ga-doped n-ZnO thin films. Semicond. Sci. Technol. 20, L43 (2005)CrossRefGoogle Scholar
24.Sayago, I., Aleixandre, M., Martínez, A., Fernández, M.J., Santos, J.P., Gutiérrez, J., Gràcia, I., Horrillo, M.C.: Structural studies of zinc oxide films grown by RF magnetron sputtering. Synth. Met. 148, 37 (2005)CrossRefGoogle Scholar
25.Chen, J.J., Gao, Y., Zeng, F., Li, D.M., Pan, F.: Effect of sputtering oxygen partial pressures on structure and physical properties of high resistivity ZnO films. Appl. Surf. Sci. 223, 318 (2004)Google Scholar
26.Jeong, S.H., Kim, I.S., Kim, S.S., Kim, J.K., Lee, B.T.: Homo-buffer layer effects and single crystalline ZnO hetero-epitaxy on c-plane sapphire by a conventional RF magnetron sputtering. J. Cryst. Growth 264, 110 (2004)Google Scholar
27.Kim, K.H., Park, K.C., Ma, D.Y.: Structural, electrical and optical properties of aluminum doped zinc oxide films prepared by radio frequency magnetron sputtering. J. Appl. Phys. 81, 7764 (1997)Google Scholar
28.Yu, X.H., Ma, J., Ji, F., Wang, Y.H., Cheng, C.F., Ma, H.L.: Thickness dependence of properties of ZnO:Ga films deposited by RF magnetron sputtering. Appl. Surf. Sci. 245, 310 (2005)CrossRefGoogle Scholar
29.Hao, X., Ma, J., Zhang, D., Yang, T., Ma, H., Yang, Y., Cheng, C., Huang, J.: Thickness dependence of structural, optical and electrical properties of ZnO:Al films prepared on flexible substrates. Appl. Surf. Sci. 183, 137 (2001)CrossRefGoogle Scholar
30.Fortunato, E., Goncalves, A., Assuncao, V., Marques, A., Aguas, H., Pereira, L., Ferreira, I., Martins, R.: Growth of ZnO:Ga thin films at room temperature on polymeric substrates: Thickness dependence. Thin Solid Films 442, 121 (2003)Google Scholar
31.Kim, H., Horwitz, J.S., Qadri, S.B., Chrisey, D.B.: Epitaxial growth of Al-doped ZnO thin films grown by pulsed laser deposition. Thin Solid Films 420–421, 107 (2002)Google Scholar
32.Lee, B.T., Kim, T.H., Jeong, S.H.: Growth and characterization of single crystalline Ga-doped ZnO films using RF magnetron sputtering. J. Phys. D: Appl. Phys. 39, 957 (2006)CrossRefGoogle Scholar
33.Jin, C., Tiwari, A., Kvit, A., Narayan, J.: Growth of epitaxial ZnO films on Si (111). J. Mater. Res. 17, 2480 (2002)Google Scholar