Properties of ZnO Thin Films Grown by Radio-frequency Magnetron Sputtering in terms of O2/Ar Mixture Flow Ratio

O2/Ar 혼합 유량비를 변수로 갖는 라디오파 마그네트론 스퍼터링으로 성장된 ZnO 박막의 특성

  • 조신호 (신라대학교 전자재료공학과)
  • Published : 2007.11.01


The structural, optical, and electrical properties of ZnO thin films grown on glass by radio-frequency (rf) magnetron sputtering were investigated. The mixture flow ratio of $O_2$ to Ar, which was operated with sputtering gas, was chosen as a parameter for growing high-qualify ZnO thin films. The structural properties and surface morphologies of the thin films were characterized by the X-ray diffraction and the atomic force microscope, respectively. As for the optical properties of the films, the optical absorbance was measured in the wavelength range of 300-1100 nm by using UV-VIS spectrophotometer. The optical transmittance, absorption coefficient, and optical bandgap energy of ZnO thin films were calculated from the measured data. The crystallinity of the films was improved and the bandgap energy was increased from 3.08 eV to 3.23 eV as the oxygen flow ratio was increased from 0 % to 50 %. Furthermore, The ultraviolet and violet luminescences were observed by using photoluminescence spectroscopy. The hall mobility was decreased with the increase of oxygen flow ratio.


  1. W. Z. Xu, Z. Z. Ye, Y. J. Zeng, L. P. Zhu, B. H. Zhao, L. Jiang, J. G. Lu, H. P. He, and S. D. Zhang, 'ZnO light-emitting diode grown by plasma-assisted metal organic chemical vapor deposition', Appl. Phys. Lett., Vol. 88, p. 173506, 2006
  2. A. A. Ibrahim and A. Ashour, 'ZnO/Si solar cell fabricated by spray pyrolysis technique', J. Mater. Sci: Mater. Electron., Vol. 17, p. 835, 2006
  3. M. Tomar, V. Gupta, K. Sreenivas, and A. Mansingh, 'Temperature stability of ZnO thin film SAW device on fused quartz', IEEE Tran. Device Mater. Reliability, Vol. 5, p. 494, 2005
  4. S. T. Tan, B. J. Chen, X. W. Sun, W. J. Fan, H. S. Kwok, X. H. Zhang, and S. J. Chua, 'Blueshift of optical band gap in ZnO thin films grown by metal-organic chemical vapor deposition', J. Appl. Phys., Vol. 98, p 013505, 2005
  5. M. Abouzaid. P. Tailpied, P. Ruterana, C. Liu, B. Xiao, S. J. Cho, Y. T. Moon, and H. Morkoc, 'A TEM study of ZnO layers deposited by MBE and rf magnetron sputtering', Superlattices and Microstructures, Vol. 39, p. 387, 2005
  6. J. H. Lee, K. H. Ko, and B. O. Park, 'Electrical and optical properties of ZnO transparent conducting films by the sol-gel method', J. Cryst. Growth, Vol. 247, p. 119, 2003
  7. R. Ondo-Ndong, F. Pascal-Delannoy, A. Boyer, A. Giani, and A. Foucaran, 'Structural properties of zinc oxide thin films prepared by r.f. magnetron sputtering', Mater. Sci. Eng. B, Vol. 97, p. 68, 2003
  8. R. Ayouchi, D. Leinen, F. Martin, M. Gabas, E. Dalchiele, and J. R. Ramos-Barrado, 'Preparation and characterization of transport ZnO thin films obtained by spray pyrolysis', Thin Solids Films, Vol. 426, p. 68, 2003
  9. V. Craciun, J. Elders, J. G. E. Gardeniers, and I. W. Boyd, 'Characteristics of high quality ZnO thin films deposited by pulsed laser deposition', Appl. Phys. Lett., Vol. 65, p. 2963, 1994
  10. Z. Y. Xue, D. H. Zhang, Q. P. Wang, and J. H. Wang, 'The blue photoluminescence emitted from ZnO films deposited on glass substrate by rf magnetron sputtering', Appl. Surface Sci., Vol. 195, p. 126, 2002
  11. W. J. Jeong and G. C. Park, 'Electrical and optical properties of ZnO thin film as a function of deposition parameters', Solar Energy Materials & Solar Cells, Vol. 65, p 37, 2001
  12. M. K. Jayaraj, A. Antony, and M. Ramachandran, 'Transport conducting zinc oxide thin film prepared by off-axis rf magnetron sputtering', Bull. Mater. Sci., Vol. 25, p. 227, 2002
  13. H. W. Kim and N. H. Kim, 'Structural studies of room-temperature RF magnetron sputtered ZnO films under different RF powered conditions', Mater. Sci. Eng. B, Vol. 103, p. 297, 2003
  14. M. L. Tu, Y. K. Su, and C. Y. Ma, 'Nitrogen-doped p-type ZnO films prepared from nitrogen gas radio-frequency magnetron sputtering', J. Appl. Phys., Vol. 100, p. 053705, 2006
  15. F. Yakuphanoglu, M. Sekerci, and O. F. Ozturk, 'The determination of the optical constants of Cu(II) compound having 1-chloro-2,3-0-cyclohexylidinepropane thin film', Opt. Comm., Vol. 239, p. 275, 2004
  16. G. H. Lee, Y. Yamamoto, M. Kourogi, and M. Ohtsu, 'Blue shift in room temperature photoluminescence from photo-chemical vapor deposited ZnO films', Thin Solids Films, Vol. 386, p. 117, 2001
  17. 황동현, 손영국, 조선호, 'Al 도핑된 ZnO 박막에서 방출되는 보라색 발광 스펙트럼', 전기전자재료학회논문지, 20권, 4호, p. 318, 2007
  18. B. J. Jin, S. Im, and S. Y. Lee, 'Violet and UV luminescence emitted from ZnO thin films grown on sapphire by pulsed laser deposition', Thin Solids Films, Vol. 366, p. 107, 2000