Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-27T01:56:10.056Z Has data issue: false hasContentIssue false

High Mobility IGZO/ITO Double-layered Transparent Composite Electrode: A Thermal Stability Study

Published online by Cambridge University Press:  05 June 2013

Aritra Dhar
Affiliation:
Department of Chemistry and Biochemistry, Arizona State University, AZ 85287, U.S.A.
T. L. Alford
Affiliation:
Department of Chemistry and Biochemistry, Arizona State University, AZ 85287, U.S.A. School for Engineering of Matter, Transport, and Energy, Arizona State University, AZ 85287, U.S.A.
Get access

Abstract

The fabrication of a thin film optoelectronic device involves the exposure of the transparent conductive oxide (TCO) to a high process temperature. Indium gallium zinc oxide (InGaZnO4 or IGZO) is a well known TCO with high optical transparency, moderate conductivity and high mobility. However, its electrical properties deteriorate after subsequent high temperature processes in air atmosphere. On the other hand indium tin oxide (ITO) has higher conductivity than IGZO and better thermal stability. Therefore, IGZO/ITO bilayers have been deposited on glass by radio frequency magnetron sputtering at room temperature and subsequently annealed at high temperatures in order to study their thermal stability. In the present work, a-IGZO layers with a thickness ranging from 10 nm to 100 nm were deposited over a 50 nm thick ITO layer. Results are compared with those from a single IGZO layered thin film without the ITO bottom layer. The structural, optical and electrical properties of the multilayers are studied with the use of scanning electron microscopy, UV–Vis spectroscopy and Hall measurement. An IGZO optimal thickness of 50 nm is found to improve the bilayer thermal stability at temperatures upto 400 °C keeping good opto-electrical properties. The sheet resistance for the optimized IGZO/ITO composite films is about 22 Ohm/sq, and the transmittance in the visible range is about 90%. The composite shows an excellent mobility above 40 cm2 /V-s and thus can be potentially applied as channel layer in thin film transistors (TFTs)

Type
Articles
Copyright
Copyright © Materials Research Society 2013 

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

Harlev, E., Gulakhmedova, T., Rubinovich, I., and Aizenshtein, G., Adv. Mater. 8, 994, (1996).CrossRefGoogle Scholar
Guillén, C., Herrero, J., Thin Solid Films 520 (2011) 1 CrossRefGoogle Scholar
Gustafsson, G., Cao, Y., Treacy, G.M., Klavetter, F., Colaneri, N., and Heeger, A. J., Nature 357, 477, (1992).CrossRefGoogle Scholar
Granqvist, C. G., Appl. Phys. A 52, 83, (1991).CrossRefGoogle Scholar
Lee, H. C., and Park, O. O., Vacuum 75, 275, (2004).CrossRefGoogle Scholar
Hichou, A. E., Kachouane, A., Bubendorff, J. L., Addou, M., Ebothe, J., Troyon, M., and Bougrine, A., Thin Solid Films 458, 263, (2004).CrossRefGoogle Scholar
Montero, J., Guillén, C., Herrero, J., Thin Solid Films 519, 7564,(2011).CrossRefGoogle Scholar
Look, D. C., Semicond. Sci. Technol. 20, S55, (2005).CrossRefGoogle Scholar
Dhar, A. and Alford, T. L., J. Appl. Phys. 112, 103113 (2012).CrossRefGoogle Scholar
Indluru, A. and Alford, T. L., J. Appl. Phys. 103, 013708, (2008).Google Scholar
Chen, S. W., and Koo, C. H., Mater. Lett. 61, 4097, (2007).CrossRefGoogle Scholar
Choi, K. H., Kim, J. Y., Lee, Y. S., and Kim, H. J., Thin Solid Films 341, 152, (1999).CrossRefGoogle Scholar
Sinha, M. K., Mukherjee, S. K., Pathak, B., Paul, R. K., Barhai, P. K., Thin Solid Films 515, 1753, (2006).CrossRefGoogle Scholar
Gadre, M. and Alford, T. L., Appl. Phys. Lett. 99, 051901 (2011)CrossRefGoogle Scholar