반도체디스플레이기술학회지 (Journal of the Semiconductor & Display Technology)

한국반도체디스플레이기술학회 (The Korean Society Of Semiconductor & Display Technology)
권호 표지

증착시 및 플라즈마 후처리에 의한 수소 주입이 투명 박막 트랜지스터에서 산화아연 채널층의 물성에 미치는 영향

Effects of Hydrogen Injection by In-Situ and Plasma Post-Treatment on Properties of a ZnO Channel Layer in Transparent Thin Film Transistors

  • 방정환 (한양대학교 전자전기제어계측공학과) ;
  • 김원 (한양대학교 전자전기제어계측공학과) ;
  • 엄현석 (한양대학교 전자전기제어계측공학과) ;
  • 박진석 (한양대학교 전자전기제어계측공학과)
  • Bang, Jung-Hwan (Dept. of Electronic, Electrical, Control and Instrumentation Engineering, Hanyang University) ;
  • Kim, Won (Dept. of Electronic, Electrical, Control and Instrumentation Engineering, Hanyang University) ;
  • Uhm, Hyun-Seok (Dept. of Electronic, Electrical, Control and Instrumentation Engineering, Hanyang University) ;
  • Park, Jin-Seok (Dept. of Electronic, Electrical, Control and Instrumentation Engineering, Hanyang University)
  • 발행 : 2010.03.31
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

We have investigated the effects of hydrogen injection via in-situ gas addition ($O_2$, $H_2$, or $O_2$ + $H_2$ gas) and plasma post-treatment (Ar or Ar + H plasma) on material properties of ZnO that is considered to be as a channel layer in transparent thin film transistors. The variations in the electrical resistivity, optical transmittance and bandgap energy, and crystal quality of ZnO thin films were characterized in terms of the methods and conditions used in hydrogen injection. The resistivity was significantly decreased by injection of hydrogen; approximately $10^6\;{\Omega}cm$ for as-grown, $1.2\;{\times}\;10^2\;{\Omega}cm$ for in-situ with $O_2/H_2\;=\;2/3$ addition, and $0.1\;{\Omega}cm$ after Ar + H plasma treatment of 90 min. The average transmittance of ZnO films measured at a wavelength of 400-700 nm was gradually increased by increasing the post-treatment time in Ar + H plasma. The optical bandgap energy of ZnO films was almost monotonically increased by decreasing the $O_2/H_2$ ratio in in-situ gas addition or by increasing the post-treatment time in Ar + H plasma, while the post-treatment using Ar plasma hardly affected the bandgap energy. The role of hydrogen in ZnO was discussed by considering the creation and annihilation of oxygen vacancies as well as the formation of shallow donors by hydrogen.

키워드

참고문헌

  1. R. Navamathavan, C. K. Choi, E. J. Yang, J. H. Lim, D. K. Hwang, and S. J. Park, "Electrical properties of ZnO-based bottom-gate thin film transistors fabricated," J. of Alloys and Compounds, Vol. 475, pp. 889-892, 2009. https://doi.org/10.1016/j.jallcom.2008.08.039
  2. R. B. M. Cross, M. M. D. Souza, S. C. Deane, and N. D. Young. "A Comparison of the Performance and Stability of ZnO-TFTs With Silicon Dioxide and Nitride as Gate Insulators," IEEE Trans. on Electron Dev., Vol.55, pp.1109-1115, 2008. https://doi.org/10.1109/TED.2008.918662
  3. P. Barquinha, A. Pimentel, A. Marques, L. Pereira, R. Martins, and E. Fortunato, "Influence of the semiconductor thickness on the electrical properties of transparent TFTs based on indium zinc oxide," J. Non- Cryst. Solids, Vol.352, pp.1749-1752, 2006. https://doi.org/10.1016/j.jnoncrysol.2006.01.067
  4. S. P. Chang, Y. W. Song, S. G. Lee, S. Y. Lee, and B. K. Ju, "Efficient suppression of charge trapping in ZnO-based transparent thin film transistors with novel $Al_2O_3/HfO_2/Al_2O_3$ structure," Appl. Phys. Lett., Vol. 92, pp. 192104, 2008. https://doi.org/10.1063/1.2924769
  5. W. J. Park, H. S. Shin, B. D. Ahn, G. H. Kim, S. M. Lee, K. H. Kim, and H. J. Kim, "Investigation on doping dependency of solution-processed Ga-doped ZnO thin film transistor," Appl. Phys. Lett., Vol. 93, pp. 083508, 2008. https://doi.org/10.1063/1.2976309
  6. R. L. Hoffman, B. J. Norris, and J. F. Wager, "ZnO-based transparent thin-film transistors," Appl. Phys. Lett., Vol. 83, pp.733, 2003.
  7. P. F. Carcia, R. S. McLean, M. H. Reilly, and G. Nunes Jr., "Transparent ZnO thin-film transistor fabricated by rf magnetron sputtering, "Appl. Phys. Lett., Vol. 82, pp. 1117, 2008.
  8. S. J. Pearton, D. P. Norton, K. Ip, Y. W. Heo, and T. Steiner, "Recent progress in processing and properties of ZnO," Progress in Materials Science, Vol.50, pp.293-340, 2005. https://doi.org/10.1016/j.pmatsci.2004.04.001
  9. J. H. Na, M. Kitamura, and Y. Arakawa, "High fieldeffect mobility amorphous InGaZnO transistors with aluminum electrodes," Appl. Phys. Lett., Vol. 93, pp. 063501, 2008. https://doi.org/10.1063/1.2969780
  10. C. G. Vand der Walle, "Hydrogen as a Cause of Doping in Zinc Oxide," Phys. Rev. Lett., Vol. 85, pp. 1012-1015, 2000. https://doi.org/10.1103/PhysRevLett.85.1012
  11. G. Goncalves, E. Elangovan, P. Barquinha, L. Pereira, R. Martins, and E. Fortunato, "Influence of post-annealing temperature on the properties exhibited by ITO, IZO and GZO thin films", Thin Solid Films, 515 (2007) 8562. https://doi.org/10.1016/j.tsf.2007.03.126
  12. M. K. Hudait, P. Modak, and S. B. Krupanidhi, "Si incorporation and Burstein-Moss shift in n-type GaAs," Mater. Sci. Eng., Vol. 56, pp. 1, 1999.
  13. J. Kennedy, A. Markwitz, Z. Li, W. Gao, C. Kendrick, S. M. Durbin, and R. Reeves, "Modification of electrical conductivity in RF magnetron sputtered ZnO films by low-energy hydrogen ion implantation," Current Appl. Phys., Vol.6, pp.495-498, 2006. https://doi.org/10.1016/j.cap.2005.11.046