Journal of the Semiconductor & Display Technology (반도체디스플레이기술학회지)

The Korean Society Of Semiconductor & Display Technology (한국반도체디스플레이기술학회)
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Study on the OLED Thin Film Encapsulation of the Al2O3 Thin Layer Formed by Atomic Layer Deposition Method

원자층 증착방법에 의한 Al2O3 박막의 OLED Thin Film Encapsulation에 관한 연구

  • Kim, Ki Rak (Department of Electronics Engineering, Gachon University) ;
  • Cho, Eou Sik (Department of Electronics Engineering, Gachon University) ;
  • Kwon, Sang Jik (Department of Electronics Engineering, Gachon University)
  • 김기락 (가천대학교 전자공학과) ;
  • 조의식 (가천대학교 전자공학과) ;
  • 권상직 (가천대학교 전자공학과)
  • Received : 2022.02.22
  • Accepted : 2022.03.25
  • Published : 2022.03.31
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Abstract

In order to prevent water vapor and oxygen permeation in the organic light emitting diodes (OLED), Al2O3 thin-film encapsulation (TFE) technology were investigated. Atomic layer deposition (ALD) method was used for making the Al2O3 TFE layer because it has superior barrier performance with advantages of excellent uniformity over large scales at relatively low deposition temperatures. In this study, the thickness of the Al2O3 layer was varied by controlling the numbers of the unit pulse cycle including Tri Methyl Aluminum(Al(CH3)3) injection, Ar purge, and H2O injection. In this case, several process parameters such as injection pulse times, Ar flow rate, precursor temperature, and substrate temperatures were fixed for analysis of the effect only on the thickness of the Al2O3 layer. As results, at least the thickness of 39 nm was required in order to obtain the minimum WVTR of 9.04 mg/m2day per one Al2O3 layer and a good transmittance of 90.94 % at 550 nm wavelength.

Keywords

Acknowledgement

본 논문은 산업통상자원부 '산업혁신인재성장지원사업'의 재원으로 한국산업기술진흥원(KIAT)의 지원을 받아 수행된 연구임. (2020년 차세대 디스플레이 공정.장비.소재 전문인력 양성사업, 과제번호 : P0012453)

References

  1. E. G. Jeong, J. H. Kwon, K. S. Kang, S. Y. Jeong, K. C. Choi, "A review of highly reliable flexible encapsulation technologies towards rollable and foldable OLEDs" J. Information. Disply., Vol. 21, No. 1, pp. 19-32, 2020. https://doi.org/10.1080/15980316.2019.1688694
  2. B.-H. Kwon, H. Lee, M. Kim, C. W. Joo, H. Cho, J. T. Lim, Y. S. Jung, "A Systematic Study of the Interactions in the Top Electrode/Capping Layer/Thin Film Encapsulation of Transparent OLEDs", J. In dustrial and Engineering Chemistry, Vol. 93 pp. 237-244, 2021. https://doi.org/10.1016/j.jiec.2020.09.029
  3. S. Sandrez, S. M. Della-Gatta. T. Maindron, "Impact of pixel surface topography onto thin-film encapsulated top-emitting organic light-emitting diodes performances", Thin Solid Films, Vol. 699, pp. 137869. 1-9, 2020. https://doi.org/10.1016/j.tsf.2020.137869
  4. D. Yu, Y. Q. Yang, Z. Chen, Y. Tao,Y. F. Liu, "Recent progress on thin-film encapsulation technologies for organic electronic devices", Optics Communications", Vol. 362, pp. 43-49, 2016. https://doi.org/10.1016/j.optcom.2015.08.021
  5. L. Wang, C. Ruan, M.Li, J. Zou, H. Tao, J. Peng, M. Xu, "Enhanced moisture barrier performance for ALD-encapsulated OLEDs by introducing an organic protective layer", J. Mater. Chem. C, Vol. 5, pp. 4017-4024, 2017. https://doi.org/10.1039/C7TC00903H
  6. Yang Yong-Qiang and Duan Yu, "Optimization of Al2O3 Films Deposited by ALD at Low Temperatures for OLED Encapsulation", J. Phys. Chem. C 118, 18783-18787, 2014. https://doi.org/10.1021/jp505974j
  7. R. Katamreddy, R. Inman, G.Jursich, A. Soulet, and C. Takoudis, "ALD and Characterization of Aluminum Oxide Deposited on Si(100) using Tris(diethylamino) Aluminum and Water Vapor," J. Electrochemical Society, Vol. 153, pp. C701-C706, 2006. https://doi.org/10.1149/1.2239258
  8. S. K. Kim, S. W. Lee, C. S. Hwang, Y.-S. Min, J. Y. Won, and J. Jeong, "Low Temperature (<100℃) Deposition of Aluminum Oxide Thin Films by ALD with O3 as Oxidant," J. Electrochemical Society, Vol. 153, pp. F69-F76, 2006. https://doi.org/10.1149/1.2177047
  9. M. G. Daniel, J. Song, S. A. S. Tali, X. Dai,and W. Zhou, "Sub-10 nm Nanolaminated Al2O3/HfO2 Coatings for Long-Term Stability of Cu Plasmonic Nanodisks in Physiological Environments", ACS Appl. Mater. Interfaces, vol. 12, ppp. 31952-31961, 2020. https://doi.org/10.1021/acsami.0c06941
  10. G. Chen, Y. Weng, F. Sun, D. Hong, X. Zhou, T. Guo , Y. Zhang, Q. Yan, C. Wu, L. Sun, " Improved barrier and mechanical properties of Al2O3/acrylic laminates using rugged fluorocarbon layers for flexible encapsulation", Organic Electronics, Vol. 97, pp. 106263:1-9, 2021. https://doi.org/10.1016/j.orgel.2021.106263
  11. M. Li, M. Xu, J. Zou, H. Tao, L. Wang, Z. Zhou, J. Peng, "Realization of Al2O3/MgO laminated structure at low temperature for thin film encapsulation in organic light-emitting diodes", Nanotechnology, Vol. 27, pp. 494003: 1-8, 2016. https://doi.org/10.1088/0957-4484/27/49/494003
  12. Chang Jo Kim and Paik Kyun Shin, "Application of Si 3 N 4 Thin Film as a Humidity Protection Layer for Organic Light Emitting Diode", J. KIEEME Vol. 23, No. 5, pp. 397-402, May 2010.