Journal of the Korean Ceramic Society (한국세라믹학회지)

The Korean Ceramic Society (한국세라믹학회)
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Microstructure and Magnetic Properties of Zn1-xCoxO Film Prepared by Pulsed DC Magnetron Sputtering

펄스 DC 마그네트론 스퍼터링법에 의한 Zn1-xCoxO 박막의 미세조직 및 자기적 특성

  • Ko, Yoon-Duk (Advanced Material Process of Information Technology, Sungkyunkwan University) ;
  • Ko, Seok-Bae (Advanced Material Process of Information Technology, Sungkyunkwan University) ;
  • Choi, Moon-Soon (Advanced Material Process of Information Technology, Sungkyunkwan University) ;
  • Tai, Weon-Pil (Institute of Advanced Materials, Inha University) ;
  • Kim, Ki-Chul (Electronics and Telecommunications Research Institute) ;
  • Kim, Jong-Min (APRO Co. Ltd.) ;
  • Soh, Su-Jeung (Advanced Material Process of Information Technology, Sungkyunkwan University) ;
  • Kim, Young-Sung (Advanced Material Process of Information Technology, Sungkyunkwan University)
  • 고윤덕 (성균관대학교 정보통신용 신기능성 소재 및 공정연구센터) ;
  • 고석배 (성균관대학교 정보통신용 신기능성 소재 및 공정연구센터) ;
  • 최문순 (성균관대학교 정보통신용 신기능성 소재 및 공정연구센터) ;
  • 태원필 (인하대학교 소재 연구소) ;
  • 김기출 (한국전자통신연구소) ;
  • 김종민 ((주) 아프로 R&D) ;
  • 서수정 (성균관대학교 정보통신용 신기능성 소재 및 공정연구센터) ;
  • 김용성 (성균관대학교 정보통신용 신기능성 소재 및 공정연구센터)
  • Published : 2005.03.01
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Abstract

[ $Zn_{1-x}Co_{x}O$ (x=0-0.3) films were grown on Corning 7059 glasses by asymmetrical bipolar pulsed dc magnetron sputtering. The c-axis orientation along (002) plane was enhanced with increasing Co concentration. The $Zn_{1-x}Co_{x}O$ films are grown with fibrous grains of tight dome shape. The transmittance spectra measured from UV-visible showed that sp-d exchange interactions and typical d-d transitions become activated with increasing Co concentration. The electrical resistivity of $Zn_{1-x}Co_{x}O$ films increased with increasing Co concentration, especially it increased greatly at $30at\% Co. X-ray photoelectron spectroscopy and alternating gradient magnetometer analyses indicated that no Co metal cluster is formed and the ferromagnetic properties are exhibited. The low electrical resistivity and room temperature ferromagnetism of $Zn_{1-x}Co_{x}O$ thin films suggested the possibility of the application to Diluted Magnetic Semiconductors (DMSs).

펄스 마그네트론 스퍼터링법을 이용하여 Co농도 변화에 따라 유리 기판 위에 ZnJ-xcoxo 박막을 제조하였다. Co 농도의 증가에 따라 $Zn_{1-x}Co_{x}O$ 박막의 c축 결정 배향성은 향상되었다. 표면 형상 분석을 통하여 매우 치밀한 박막이 성장되었음을 찰 수 있었다. 박막의 UV-visible투과율 측정 결과, $Co^{2+}$ 이온에 의한 sp-d상호교환 작용과 d-d 천이를 확인할 수 있었다. $Zn_{1-x}Co_{x}O$ 박막의 비저항은 $10^{-2}\~10^{-3}\;\Omega{\cdot}cm$의 값을 가지며 Co농도의 증가에 따라 박막의 비저항은 증가하였고, 특히 $30\;at\%$ Co에서는 박막의 결정성 저하로 인하여 급격한 비저항 증가가 발생하였다. X-ray photoelecoon specooscopy분석을 통해 Co와 O 간의 결합 상태를 확인하였으며, alternating gradient magnetometer측정 결과 $Zn_{1-x}Co_{x}O$ 박막의 상온 강자성 치력 현상을 관찰할 수 있었다. 낮은 비저항 및 상온 강자성 이력 특성을 갖는 $Zn_{1-x}Co_{x}O$ 박막은 자성 반도체 소자로의 응용 가능성을 나타내었다 .

Keywords

References

  1. A. E. Jimenez-Gonzalez, 'Modification of ZnO Thin Films by Ni, Cu, and Cd Doping,' J. of Solid State Chem., 128 176-80 (1997) https://doi.org/10.1006/jssc.1996.7166
  2. T. R. N Kutty and N. Raghu, 'Varistors Based on Polycrystalline ZnO:Cu,' Appl. Phys. Lett., 54 1796-98 (1989) https://doi.org/10.1063/1.101267
  3. K. Sato and H. Katayama-Yoshida, 'Electronic Structure and Ferromagnetism of Transition-Metal-Impurity-Doped Zinc Oxide,' Phys. B, 308-320 904-07 (2001)
  4. S. G Yang, A. B. Pakhomov, S. T. Hung, and C. Y. Wong, 'Room Temperature Magnetism in Sputtered (Zn,Co)O Films,' IEEE Trans. Magn., 38 2877-79 (2002) https://doi.org/10.1109/TMAG.2002.803133
  5. A. B. Pakhomov, B. K. Roberts, A. Tuan, V. Shutthanandan, D. McCready, S. Thevuthasan, S. A. Chambers, and K. M. Krishnan, 'Studies of Two- and Three-Dimensional ZnO:Co Structures through Different Synthetic Routes,' J. of Appl. Phys., 95 7393-95 (2004) https://doi.org/10.1063/1.1669224
  6. N. Jedrecy, H. J. von Bardeleben, Y. Zheng, and J.-L. Cantin, 'Electron Paramagnetic Resonance Study of $Zn_{1-x}Co_xO$: A Predicted High-Temperature Ferromagnetic Semiconductor,' Phys. Rev. B, 69 1-4 (2004)
  7. W. Prellier, A. Fouchet, B. Mercey, C. Simon, and B. Raveau, 'Laser Ablation of Co:ZnO Films Deposited from Zn and Co Metal Targets on (0001) $Al_2O_3$ Substrates,' Appl. Phys. Lett., 82 3490-92 (2003) https://doi.org/10.1063/1.1578183
  8. S. S. Yan, C. Ren, X. Wang, W. Xin, Z. X. Zhou, L. M. Mei, M. J. Ren, Y. X. Chen, Y. H. Liu, and H. Garmestani, 'Ferromagnetism and Magnetoresistance of Co-ZnO Inhomogeneous Magnetic Semiconductors,' Appl. Phys. Lett., 84 2376-78 (2004) https://doi.org/10.1063/1.1690881
  9. H. J. Kim, I. C. Song, J. H. Sim, H. Kim, D. Kim, Y. E. Ihm, and W. K. Choo, 'Growth and Characterization of Spineltype Magnetic Semiconductor $ZnCo_2O_4$ by Reactive Magnetron Sputttering,' Phys. Stat. Sol., 241 1553-56 (2004) https://doi.org/10.1002/pssb.200304656
  10. N. A. Theodoropoulou, A. F. Hebard, D. P. Norton, J. D. Budai, L. A. Boatner, J. S. Lee, Z. G. Khim, Y. D. Park, M. E. Overberg, S. J. Pearton, and R. G. Wilson, 'Ferrornagnetism in Co- and Mn-Doped ZnO,' Solid-State Electronics, 47 2231-35 (2003) https://doi.org/10.1016/S0038-1101(03)00203-X
  11. Z. W. Jin, T. Fukurnura, K. Hasegawa, Y. Z. Yoo, K. Ando, T. Sekiguchi, P. Ahmet, T. Chikyow, T. Hasegawa, H. Koinuma, and M. Kawasaki, 'Optical and Electrical Properties of Co-Doped Epitaxial ZnO Films,' J. of Crystal Growth, 237-239 548-52 (2002) https://doi.org/10.1016/S0022-0248(01)01976-5
  12. N. Viart, M. Richard-Plouet, D. Muller, and G. Pourroy, 'Synthesis and Characterization of Co/ZnO Nanocomposites : Towards New Perspectives Offered by Metal/Piezoelectric Composite Materials,' Thin Solid Films, 437 1-9 (2003) https://doi.org/10.1016/S0040-6090(02)00785-X
  13. S. H. Jeong and J. H. Boo, 'Influence of Target-to-Substrate Distance on the Properties of AZO Films Grown by RF Magnetron Sputtering,' Thin Solid Films, 447-48 105-10 (2004) https://doi.org/10.1016/j.tsf.2003.09.031
  14. J. M. Ting and B. S. Tsai, 'DC Reactive Sputter Deposition of ZnO:Al Thin Film on Glass,' Mater. Chem. Phys., 72 273-77 (2001) https://doi.org/10.1016/S0254-0584(01)00451-5
  15. H. J. Lee, S. Y. Jeong, C. R. Cho, and C. H. Park, 'Study of Diluted Magnetic Semiconductor : Co-Doped ZnO,' Appl. Phys. Lett., 81 4020-22 (2002) https://doi.org/10.1063/1.1517405
  16. D. Song, A. G. Aberle, and J. Xia, 'Optimisation of ZnO:Al Films by Change of Sputter Gas Pressure for Solar Cell Application,' Appl. Surf. Sci., 195 291-96 (2002) https://doi.org/10.1016/S0169-4332(02)00611-6
  17. K. Veda, H. Tabata, and T. Kawai, 'Magnetic and Electric Properties of Transition-Metal-Doped ZnO Films,' Appl. Phys. Lett., 79 988 (2001) https://doi.org/10.1063/1.1384478
  18. Z. Jin, M. Murakami, T. Fukumura, Y. Matsumoto, A. Ohtomo, M. Kawasaki, and H. Koinuma, 'Combinatorial Laser MBE Synthesis of 3d Ion Doped Epitaxial ZnO Thin Films,' J. of Cryst. Growth, 214-215 55-8 (2000) https://doi.org/10.1016/S0022-0248(00)00058-0
  19. Y. Z. Yoo, T. Fukumura, Z. Jin, Hasegawa, M. Kawasaki, P. Ahmet, T. Chikyow, and H. Koinuma, 'ZnO-CoO Solid Solution Thin Films,' J. of Appl. Phys., 90 4246-50 (2001) https://doi.org/10.1063/1.1402142
  20. F. K. Shan and Y. S. Yu, 'Band Gap Energy of Pure and Al-Doped ZnO Thin Films,' J. Eur. Ceram. Soc., 24 1869-72 (2004) https://doi.org/10.1016/S0955-2219(03)00490-4
  21. J. Diouri, J. P. Lascaray, and M. E. Amrani, 'Effect of the Magnetic Order on the Optical-Absorption Edge in $Cd_{1-x}Mn_xTe$,' Phys. Rev. B, 31 7995 (1985) https://doi.org/10.1103/PhysRevB.31.7995
  22. K. J. Kim and Y. R. Park, 'Spectroscopic Ellipsometry Study of Optical Transitions in $Zn_{1-x}Co_xO$ Alloys,' Appl. Phys. Lett., 81 1420 (2002) https://doi.org/10.1063/1.1501765
  23. J. F. Moulder, et al., 'Handbook of X-Ray Photoelectron Spectroscopy,' Phys. Electronics, Inc. (1992)
  24. C. D. Wagner, W. M. Riggs, L. E. Davis, and J. F. Moulder, in Handbook of X-ray photoelectron Sectroscopy, Edited by G E. Mulenberg p. 78, Perkin-Elmer, 1979
  25. J. H. Park, M. G. Kim, H. M. Jang, S. Ryu, and Y. M. Kim, 'Co-Metal Clustering as the Origin of Ferromagnetism in Co-Doped ZnO Thin Films,' Appl. Phys. Lett., 84 1338-40 (2004) https://doi.org/10.1063/1.1650915
  26. J. H. Kim, H. Kim, D. Kim, Y. E. Ihm, and W. K. Choo, 'The Origin of Room Temperature Ferromagnetism in Cobalt-Doped Zinc Oxide Thin Films Fabricated by PLD,' Sci. Direct, 24 1847-51 (2004)
  27. H. Munekata, T. Abe, S. Koshihara, A. Oiwa, M. Hirasawa, S. Katsumoto, Y. lye, C. Urano, and H. Takagi, 'LightInduced Ferromagnetism III-V-Based Diluted Magnetic Semiconductor Heterostructures,' J. of Appl. Phys., 81 4862 (1997) https://doi.org/10.1063/1.364889
  28. S. Koshihara, A. Oiwa, M. Hirasawa, S. Katsumoto, Y. lye, C. Urano, H. Takgi, and H. Munekata, 'Ferromagnetic Order Induced by Photogenerated Carriers in Magnetic III-V Semiconductor Heterostructures of (In,Mn)As/GaSb,' Phys. Rev. Lett., 78 4617 (1997) https://doi.org/10.1103/PhysRevLett.78.4617