Journal of the Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회논문지)

The Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회)
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Etching Characteristics of GST Thin Films using Inductively Coupled Plasma of Cl2-Ar Gas Mixtures

Cl2-Ar 혼합가스를 이용한 GST 박막의 유도결합 플라즈마 식각

  • 민남기 (고려대학교 제어계측공학과) ;
  • 김만수 (고려대학교 제어계측공학과) ;
  • ;
  • 김성일 (대전대학교 IT 전자공학과) ;
  • 권광호 (고려대학교 제어계측공학과)
  • Published : 2007.10.01
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Abstract

In this work, the etching characteristics of $Ge_2Sb_2Te_5(GST)$ thin films were investigated using an inductively coupled plasma (ICP) of $Cl_2/Ar$ gas mixture. To analyze the etching mechanism, an optical emission spectroscopy (OES) and surface analysis using X-ray photoelectron spectroscopy (XPS) were carried out. The etch rate of the GST films decreased with decreasing Ar fraction. At the same time, high selective etch rate over $SiO_2$ films was obtained and the selectivity over photoresist films decreased with increasing the he fraction. From XPS results, we found that Te halides were formed at the etching surface and Te halides limited the etch rate of the GST films.

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References

  1. B. Hyot, L. Poupinet, V. Gehanno, and P. J. Desre, 'Analysis of writing and erasing behaviours in phase change materials', Journal of Magnetic Materials, Vol. 249, p. 504, 2002 https://doi.org/10.1016/S0304-8853(02)00470-5
  2. X. S. Miao, L. P. Shi, P. K Tan, J. M. Li, K G. Lim, X. Hu, and T. C. Chong, 'Multispeed rewritable optical-recording method with an initialization-free phase-change disk', Applied Optics, Vol. 43, p. 1140, 2004 https://doi.org/10.1364/AO.43.001140
  3. S. Lai and T. Lowery, 'OUM - A 180 nm Nonvolatile Memory Cell Element Technology For Stand Alone and Embedded Applications', IEDM Tech Dig, 36.5.1, 2001
  4. S. Lai, 'Current status of the phase change memory and its future', IEDM Tech Dig,. 10.1.1, 2004
  5. W. Y. Cho, B.-H. Cho, B.-G. Choi, H.-R Oh, S. Kang, K.-S. Kim, K.-H. Kim, D.-E. Kim, C.-K Kwak, H.-G. Byun, Y. H. wang, S. Ahn, G.-H. Koh, G. Jeong, H. Jeong, and K. Kim, 'A 0.18-um, 3.0-V, 64-Mb nonvolatile phase-transition random access memory (PRAM)', IEEE Journal of solid-state circuits, Vol. 40, No. 1, p. 293, 2005 https://doi.org/10.1109/JSSC.2004.837974
  6. S. Senkader and C. D. Wright, 'Models for phase-change of $Ge_{2}Sb_{2}Te_{5}$ in optical and electrical memory devices', Journal of applied physics, Vol. 95, p. 504, 2004 https://doi.org/10.1063/1.1633984
  7. H. Y. Cheng, C. A. Jong, c. M. Lee, and T. S. Chin, 'Wet-etching characteristics of $Ge_{2}Sb_{2}Te_{5}$ thin films for phase-change memory', IEEE Transactions on Magnetics, Vol. 41, p. 1031, 2005 https://doi.org/10.1109/TMAG.2004.842136
  8. H. Park, J. W. Lee, and C. W. Chung, 'Integrated ferroelectrics', Vol. 80, p. 207, 2003 https://doi.org/10.1080/10584580600657674
  9. M. S. Kim, N.-K. Min, S. J. Yun, H. W. Lee, A. Efremov, and K.-H. Kwon, 'On the Etching Mechanism of $ZrO_{2}$ Thin Films in Inductively Coupled $BCl_{3}/Ar$ Plasma', Microelectronics Engineering, in press
  10. R. Payling and P. Lakins, 'Optical Emission Lines of the Elements', John Wiley & Sons Ltd., p. 69, 2002
  11. L. Sha and J. P. Chang, 'Plasma etching selectivity of $ZrO_{2}$ to Si in $BCl_{3}/Cl_{2}$ plasma', Journal of Vacuum Science Technology, A21(6), Vol. 21, No. 6, p. 1915, 2003
  12. J. F. Moulder, W. F. Sticke, P. E. Sobol, and K. D. Bomben, 'Handbook of X-ray Photoelectron Spectroscopy', Physical Electronics, Inc, 1995
  13. H. Y. Cheng, C. A. Jong, R.-J. Chung, T.-S. C, and R.-T. Huang, 'Wet etching of $Ge_{2}Sb_{2}Te_{5}$ films and switching properties of resultant phase change memory cells', Semicond. Sci. Technol., Vol. 20, p. 1111, 2005 https://doi.org/10.1088/0268-1242/20/11/002
  14. D. W. Green and J. O. Maloney, 'Perry's chemical engineers' handbook', 6th ed, McGraw-Hill, Inc, 1984