Korean Journal of Metals and Materials (대한금속재료학회지)

The Korean Institute of Metals and Materials (대한금속재료학회)
권호 표지

Electron Beam Evaporated ITO Transparent Electrode for Highly Efficiency GaN-based Light Emitting Diode

고효율 질화갈륨계 발광 다이오드용 전자선 증착 ITO 투명 전도 전극 연구

  • Seo, Jae Won (Department of Materials Science and Metallurgical Engineering, Sunchon National University) ;
  • Oh, Hwa Sub (Department of Materials Science and Metallurgical Engineering, Sunchon National University) ;
  • Kang, Ki Man (Department of Materials Science and Metallurgical Engineering, Sunchon National University) ;
  • Moon, Seong Min (Department of Materials Science and Metallurgical Engineering, Sunchon National University) ;
  • Kwak, Joon Seop (Department of Materials Science and Metallurgical Engineering, Sunchon National University) ;
  • Lee, Kuk Hwe (Epiplus Co., Ltd.) ;
  • Lee, Woo Hyun (Epiplus Co., Ltd.) ;
  • Park, Young Ho (Epiplus Co., Ltd.) ;
  • Park, Hae Sung (Epiplus Co., Ltd.)
  • Received : 2008.06.03
  • Published : 2008.10.25
⟨ Previous Next ⟩

Abstract

In order to develop transparent electrodes for high efficiency GaN-based light emitting diodes (LEDs), the electrical and optical properties of the electron beam evaporated ITO contacts have been investigated as a function of the deposition temperature and flow rate of oxygen during the deposition. As the deposition temperature increases from $140^{\circ}C$ to $220^{\circ}C$, the resistivity of the ITO films decreases slightly from $4.0{\times}10^{-4}{\Omega}cm$ to $3.3{\times}10^{-4}{\Omega}cm$, meanwhile the transmittance of the ITO films significantly increases from 67% to 88% at the wavelength of 470 nm. When the flow rate of oxygen during the deposition increases from 2 sccm to 4 sccm, the resistivity of the ITO films increases from $3.6{\times}10^{-4}{\Omega}cm$ to $7.4{\times}10^{-4}{\Omega}cm$, meanwhile the transmittance of the ITO films increases from 86% to 99% at 470 nm. Blue LEDs fabricated with the electron beam evaporated ITO electrode show that the ITO films deposited at $200^{\circ}C$ and 3 sccm of the oxygen flow rate give a low forward-bias voltage of 3.55 V at injection current of 20 mA with a highest output power.

Keywords

Acknowledgement

Supported by : 한국학술진흥재단

References

  1. T. C. Wen, S. J. Chang, L. W. Wu, Y. K. Su, W. C. Lai, C. H. Kuo, C. H. Chen, J. L. Sheu, and J. F. Chen, IEEE Trans. Electron. Devices. 49, 1093 (2002). https://doi.org/10.1109/TED.2002.1003762
  2. L. W. Wu, S. J. Chang, T. C. Wen, Y. K. Su, W. C. Lai, C. H. Kuo, C.H. Kuo, C. H. Chen, and J. K. Sheu, IEEE J. Quantum Electron. 38, 446 (2002). https://doi.org/10.1109/3.998615
  3. C. H. Kuo, S. J. Chang, Y.K. Su, J. F. Chen, L.W. Wu, J. K. Sheu, C. H. Chen, and G. C. Chi, IEEE Electron. Dev. Lett. 23, 240 (2002). https://doi.org/10.1109/55.998863
  4. C. H. Ko, Y. K. Su, S. J. Chang, T. M. Kuan, C. I. Chiang, W. H. Lan, W. H. Lin, and J. Webb, Jpn. J. Appl. Phys. 41, 2489 (2002). https://doi.org/10.1143/JJAP.41.2489
  5. J. S. Kwak and Y. Park, J. Korean Phys. Soc. 45, 988 (2004).
  6. S. Y. Kim, H. W. Jang, and J.-L. Lee, Appl. Phys. Lett. 82, 61 (2003). https://doi.org/10.1063/1.1534630
  7. J. O. Song, J. S. Kwak, Y. Park, and T. Y. Seng, Appl. Phys. Lett. 86, 213505 (2005). https://doi.org/10.1063/1.1937987
  8. J. O. Song, D. S. Leem, J. S. Kwak, Y. Park and T. Y. Seong, IEEE Photon. Technol. Lett. 17, 291 (2005). https://doi.org/10.1109/LPT.2004.839783
  9. H. H. Yu, S. J. Hwang, M. C. Tseng, C. C. Tseng, Opt. Commun. 259, 187 (2006). https://doi.org/10.1016/j.optcom.2005.08.053
  10. L. J. Meng and M. P. dos Santos, Thin Solid Films. 303, 151 (1997). https://doi.org/10.1016/S0040-6090(97)00050-3
  11. T. Minami, H. Sonohra, T. Kakumu, and S. Takata, Thin Solid Films. 270, 37 (1995). https://doi.org/10.1016/0040-6090(95)06889-9
  12. P. Lippens, A. Segers, J. Haemers, and R. De Gryse, Thin Solid Films. 317, 405 (1998). https://doi.org/10.1016/S0040-6090(97)00632-9
  13. H. W. Jang, C. M. Jeon, J. K. Kim, and J. L. Lee, Appl. Phys. Lett. 78, 2015 (2001). https://doi.org/10.1063/1.1360784
  14. J. I. Lee and S. K. Choi, J. Kor. Ceram. Soc. 37, 686 (2000).
  15. Y. Ohhata, F. Shinoki, and S. Yoshida, Thin Solid Films. 59, 255 (1979). https://doi.org/10.1016/0040-6090(79)90298-0
  16. B. E. Sernelius, K. F. Berggren, Z. C. Jin, I. Hamberg, and C. G. Granqvist, Phys. Rev. B37, 10244 (1988).
  17. K. Suzuki, N. Hashimoto, T.Oyama, J. Shimizu, Y. Akao, and H. Kojima, Thin Solid Films. 226, 104 (1993). https://doi.org/10.1016/0040-6090(93)90213-9
  18. J. George and C. S. Menon, Surf. Coat. Technol. 132, 45 (2000). https://doi.org/10.1016/S0257-8972(00)00726-X
  19. A. E. Hichou, A. Kachouane, J. L. Bubendorff, M. Addou, J. Ebothe, M. Troyon, and A. Bougrine, Thin Solid Films. 458, 263 (2004). https://doi.org/10.1016/j.tsf.2003.12.067
  20. A. Salehi, Thin Solid Films. 324, 214 (1998). https://doi.org/10.1016/S0040-6090(98)00371-X
  21. M. Nisha, S. Anusha, A. Antony, R. Manoj, and M. K. Jayaraj, Appl. Surf. Sci. 252, 1430 (2005). https://doi.org/10.1016/j.apsusc.2005.02.115
  22. L. J. Meng and M. P. dos Santos, Thin Solid Films. 322, 56 (1998). https://doi.org/10.1016/S0040-6090(97)00939-5
  23. Y. L. Choi, J. Kor. Inst. Met. & Mater. 45, 579 (2007).
  24. H. Ma, J. S. Cho, and C. H. Park, Surf. Coat. Technol. 153, 131 (2002). https://doi.org/10.1016/S0257-8972(01)01693-0