Hostname: page-component-745bb68f8f-b95js Total loading time: 0 Render date: 2025-01-12T05:25:56.474Z Has data issue: false hasContentIssue false
  • English
  • Français

High Mobility ZnO thin film transistors using the novel deposition of high-k dielectrics

Published online by Cambridge University Press:  05 April 2011

D. K. Ngwashi ,
R. B. M. Cross ,
S. Paul ,
Andrian P. Milanov  and
Anjana Devi
D. K. Ngwashi
Affiliation:
Emerging Technologies Research Centre, De Montfort University Leicester LE1 9BH, UK
R. B. M. Cross
Affiliation:
Emerging Technologies Research Centre, De Montfort University Leicester LE1 9BH, UK
S. Paul
Affiliation:
Emerging Technologies Research Centre, De Montfort University Leicester LE1 9BH, UK
Andrian P. Milanov
Affiliation:
Inorganic Materials Chemistry Group, Inorganic Chemistry II, Ruhr-University Bochum, 44801 Bochum, Germany
Anjana Devi
Affiliation:
Inorganic Materials Chemistry Group, Inorganic Chemistry II, Ruhr-University Bochum, 44801 Bochum, Germany
Get access

Abstract

In order to investigate the performance of ZnO-based thin film transistors (ZnO-TFTs), we fabricate devices using amorphous hafnium dioxide (HfO2) high-k dielectrics. Sputtered ZnO was used as the active channel layer, and aluminium source/drain electrodes were deposited by thermal evaporation, and the HfO2 high-k dielectrics are deposited by metal-organic chemical vapour deposition (MOCVD). The ZnO-TFTs with high-k HfO2 gate insulators exhibit good performance metrics and effective channel mobility which is appreciably higher in comparison to SiO2-based ZnO TFTs fabricated under similar conditions. The average channel mobility, turn-on voltage, on-off current ratio and subthreshold swing of the high-k TFTs are 31.2 cm2V-1s-1, -4.7 V, ~103, and 2.4 V/dec respectively. We compared the characteristics of a typical device consisting of HfO2 to those of a device consisting of thermally grown SiO2 to examine their potential for use as high-k dielectrics in future TFT devices.

Keywords

thin filmdevicessemiconducting
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1315: Symposium MM – Transparent Conducting Oxides and Applications , 2011 , mrsf10-1315-mm06-18
Copyright
Copyright © Materials Research Society 2011

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. Moore, A.R., Electron and hole drift mobility in amorphous silicon . Applied Physics Letters, 1976. 31(11): p. 761–4.Google Scholar
2. Gleskova, H. and Wagner, S., Electron mobility in amorphous silicon thin-film transistors under compressive strain . Applied Physics Letters, 2001. 79(20): p. 3347–9.Google Scholar
3. Yi, T., et al. , Study of light induced instability in intrinsic hydrogenated amorphous silicon films by the photomixing technique . Applied Physics Letters, 1996. 68(5): p. 640–2.Google Scholar
4. Voronkov, E.N. Current instability in a-Si:H solar cells after their exposure to light. 2001. Russia: MAIK Nauka.Google Scholar
5. Ngwashi, D., Cross, R.B., and Paul, S.. Electrically Air-stable ZnO Thin Film Produced by Reactive RF Magnetron Sputtering for Thin Film Transistors Applications . in Mat. Res. Soc. 2009. 1201: p. 153–158Google Scholar
6. Hirao, T., et al. , Bottom-gate zinc oxide thin-film transistors (ZnO TFTs) for AM-LCDs . IEEE Transactions on Electron Devices, 2008. 55(11): p. 3136–3142.Google Scholar
7. Hirao, T., et al. Distinguished paper: High mobility top-gate Zinc Oxide Thin-Film Transistors (ZnO-TFTs) for active-matrix liquid crystal displays. 2006. San Francisco, CA, United states: Society for Information Display.Google Scholar
8. Carcia, P.F., et al. , Transparent ZnO thin-film transistor fabricated by rf magnetron sputtering . Applied Physics Letters, 2003. 82(7): p. 1117–1119.Google Scholar
9. Nishii, J., et al. , High mobility thin film transistors with transparent ZnO channels . Japanese Journal of Applied Physics, Part 2 (Letters), 2003. 42(4A): p. 347–9.Google Scholar
10. Hossain, F.M., et al. , Modeling and simulation of polycrystalline ZnO thin-film transistors . Journal of Applied Physics, 2003. 94(12): p. 7768–77.Google Scholar
11. Milanov, A.P., et al. , Lanthanide oxide thin films by metalorganic chemical vapor deposition employing volatile guanidinate precursors . Chemistry of Materials, 2009. 21(22): p. 5443–5455.Google Scholar
12. Remashan, K., et al. , Impact of hydrogenation of ZnO TFTs by plasma-deposited silicon nitride gate dielectric . IEEE Transactions on Electron Devices, 2008. 55(10): p. 2736–43.Google Scholar
13. Taur, Y. and Ning, T.H., Fundamentals of Modern VLSI Devices. 1998: Cambridge University Press. p. 128.Google Scholar
14. Park, Y.R., Kim, J., and Kim, Y.S., Effect of hydrogen doping in ZnO thin films by pulsed DC magnetron sputtering . Applied Surface Science, 2009. 255(22): p. 9010–9014.Google Scholar
15. Shi, G.A., et al. , “Hidden hydrogen” in as-grown ZnO . Applied Physics Letters, 2004. 85(23): p. 5601–3.Google Scholar