Optimization of Electrical/Optical Properties of ITO/Al Based Reflector for Vertical-type UV LEDs via SF6 Plasma Treatments

불소계열 플라즈마 처리를 통한 수직형 UV LED용 ITO/Al 기반 반사전극의 전기적/광학적 특성 최적화

  • Shin, Ki-Seob (School of Electrical Engineering, Korea University) ;
  • Kim, Dong-Yoon (School of Electrical Engineering, Korea University) ;
  • Kim, Tae-Geun (School of Electrical Engineering, Korea University)
  • 신기섭 (고려대학교 전기전자전파공학과) ;
  • 김동윤 (고려대학교 전기전자전파공학과) ;
  • 김태근 (고려대학교 전기전자전파공학과)
  • Received : 2011.07.29
  • Accepted : 2011.10.22
  • Published : 2011.11.01


We optimize electrical and optical properties of thermal and SF6 plasma treated indium tin oxide (ITO)/Al based reflector for high-power ultraviolet (UV) light-emitting diodes (LEDs). After thermal and $SF_6$ plasma treatments of ITO/Al reflector, the specific contact resistance decreased from $1.04{\times}10^{-3}\;{\Omega}{\cdot}cm^2$ to $9.21{\times}10^{-4}\;{\Omega}{\cdot}cm^2$, while the reflectance increased from 58% to 70% at the 365 nm wavelength. The low resistance and high reflectance of ITO/Al reflector are attributed to the reduced Schottky barrier height (SBH) between the ITO and AlGaN by large electronegativity of fluorine species and reduced interface roughness between the ITO and Al, respectively.


Supported by : 한국연구재단


  1. H. Rodriguez, N. Lobo, S. Einfeldt, A. Knauer, M. Weyers, and M. Kneissl, Phys. Status Solidi., A207, 11 (2010).
  2. H. S. Kim, S. J. Park, and H. S. Hwang, Appl. Phys. Lett., 81, 7 (2002).
  3. M. S. Shur and R. Gaska, IEEE Trans. Electron Dev., 57, 1 (2010).
  4. T. Fujii, A. David, Y. Gao, M. Iza, S. P. DenBaars, E. L. Hu, C. Weisbuch, and S. Nakamura, Phys. Status Solidi., C2, 7 (2005).
  5. D. H. Kim, C. O. Cho, Y. G. Roh, H. S. Jeon, and Y. S. Park, Appl. Phys. Lett., 87, 203508 (2005).
  6. C. F. Chu, C. C. Cheng, W. H. Liu, J. Y. Chu, F. H. Fan, H. C. Cheng, T. Dong, and D. A. Tran, Proceedings of the IEEE, 98, 7 (2010).
  7. C. G. Granqvist and A. Hultaker, Thin Solid Films, 411, 1 (2002).
  8. W. H. Lee, D. H. Kim, D. J. Chae, J. W. Yang, J. I. Sim, Y. M. Sung, and T. G. Kim, Electrochem. Solid State Lett., 13, 4 (2010).
  9. W. F. Wu and B. S. Chiou, Appl. Surf. Sci., 68, 497 (1993).