Journal of the Semiconductor & Display Technology (반도체디스플레이기술학회지)

The Korean Society Of Semiconductor & Display Technology (한국반도체디스플레이기술학회)
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Sputtering Growth of ZnO Thin-Film Transistor Using Zn Target

Zn 타겟을 이용한 ZnO 박막트랜지스터의 스퍼터링 성장

  • Yu, Meng (Department of Electrical and Computer Engineering, Ajou University) ;
  • Jo, Jungyol (Department of Electrical and Computer Engineering, Ajou University)
  • 우맹 (아주대학교 정보통신대학 전자공학과) ;
  • 조중열 (아주대학교 정보통신대학 전자공학과)
  • Received : 2014.09.01
  • Accepted : 2014.09.22
  • Published : 2014.09.30
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Abstract

Flat panel displays fabricated on glass substrate use amorphous Si for data processing circuit. Recent progress in display technology requires a new material to replace the amorphous Si, and ZnO is a good candidate. ZnO is a wide bandgap (3.3 eV) semiconductor with high mobility and good optical transparency. ZnO is usually grown by sputtering using ZnO ceramic target. However, ceramic target is more expensive than metal target, and making large area target is very difficult. In this work we studied characteristics of ZnO thin-film transistor grown by rf sputtering using Zn metal target and $CO_2$. ZnO film was grown at $450^{\circ}C$ substrate temperature, with -70 V substrate bias voltage applied. By using these methods, our ZnO TFT showed $5.2cm^2/Vsec$ mobility, $3{\times}10^6$ on-off ratio, and -7 V threshold voltage.

Keywords

References

  1. Nomura, K., Ohta, H., Takagi, A., Kamiya, T., Hirano, M., and Hosono, H., "Room-temperature fabrication of transparent flexible thin-film transistors using amorphous oxide semiconductors," Nature, Vol. 432, 488, 2004. https://doi.org/10.1038/nature03090
  2. Jo, J., Seo, O., Choi, H., and Lee, B., "Enhancement-mode ZnO thin-film transistor grown by metalorganic chemical vapor deposition," Applied Physics Express, Vol. 1, 041202, 2008. https://doi.org/10.1143/APEX.1.041202
  3. Abe Y., Shinya K., Chiba Y., Kawamura M., and Sasaki K., "Time-dependent variation of the target mode in reactive sputtering of Al-$O_2$ system," Vacuum, Vol. 84, 1365, 2010. https://doi.org/10.1016/j.vacuum.2009.12.021
  4. Li, S., Cai, Y., Han, D., Wang, Y., Sun, L., Chan, M., and Zhang, S., "Low-Temperature ZnO TFTs Fabricated by Reactive Sputtering of Metallic Zinc Target," IEEE Transactions on Electron Devices, Vol. 59, 2555, 2012. https://doi.org/10.1109/TED.2012.2205151
  5. Takayanagi, S., Yanagitani, T., and Matsukawa, M., "Effect of metal mode and oxide mode on unusual c-axis parallel oriented ZnO film growth on Al/glass substrate in a reactive magnetron sputtering of Zn target," Journal of Crystal Growth Vol. 363, 22, 2013. https://doi.org/10.1016/j.jcrysgro.2012.09.016
  6. Yoo, D., Kim, H., Kim, J., and Jo, J., "Current Variation in ZnO Thin-Film Transistor under Different Annealing Conditions," J. of the Semiconductor & Display Technology, Vol. 13, 63, 2014.
  7. Erhart, P., Klein, A., and Albe, K., "First-principles study on the structure and stability of oxygen related point defects in zinc oxide," Phys. Rev. B, Vol. 72, 085213, 2005. https://doi.org/10.1103/PhysRevB.72.085213