Effect of asymmetric magnetic fields on the interface shape in Czochralski silicon crystals

Cz 실리콘 단결정에서 비대칭 자기장이 고액 계면에 미치는 영향

  • Hong, Young-Ho (Crystal Growth Technology Team, LG Siltron, Division of Materials Science and Engineering, Hanyang University) ;
  • Shim, Kwang-Bo (Division of Materials Science and Engineering, Hanyang University)
  • 홍영호 (LG Siltron, 한양대학교, 신소재공학과) ;
  • 심광보 (한양대학교, 신소재공학과)
  • Published : 2008.08.31

Abstract

Silicon single crystals are grown by Czochralski (CZ) method in different growing conditions. The different shapes of the crystal-melt interface are obtained with various magnetic fields. Effects of zero-Gauss plane (ZGP) shape and magnetic intensity (MI) on the crystal-melt interface in the crystal experimentally are investigated. The shape of ZGP is not only flat but also parabolic, which is due to magnetic ratio (MR) of the lower to upper current densities in the configurations of the cusp-magnetic fields. As the MR increases, the crystal-melt interface becomes more concave. It means that the hot melt can be easily transported to the crystal-melt interface with increasing the MR. Effective shape of the crystal-melt interface is found to depend on the magnetic field in cusp-magnetic CZ method. The experimental results are compared with other studies and discussed.

Cz법을 이용하여 다양한 성장 조건하에서 실리콘 단결정이 성장되었따. 고액 계면 형상의 차이는 다양한 자기장 분포를 통하여 구현되었으며 결정의 고액 계면에 있어 ZGP(zero-Gauss plane) 형태와 자기장 세기(MI)의 효과가 실험적으로 연구되었따. ZGP의 형태는 커습 자기장에 있어 상부 및 하부 코일에 인가되는 자기장의 비율(MR)로 인하여 평평하거나 포물선의 형태를 갖게 된다. MR이 증가함에 따라 고액 계면은 더욱 음각(more concave)의 형태가 되고 이는 MR 증가에 따른 고액 계면으로의 뜨거운 융액이 쉽게 유입될 수 있음을 의미한다. 고액 계면의 효과적인 형상은 자기장 분포에 의존됨을 발견하였으며 실험결과는 다른 연구와 비교하였다.

Keywords

References

  1. V.V. Voronkov, "The mechanism of swirl defects formation in silicon", J. Crystal Growth 59 (1982) 625 https://doi.org/10.1016/0022-0248(82)90386-4
  2. Y. Won, K. Kakimoto and H. Ozoe, "Transient threedimensional numerical computation for unsteady oxygen concentration in a silicon melt during a Czochralski process under a cusp-shaped magnetic field", J. Crystal Growth 233 (2001) 622 https://doi.org/10.1016/S0022-0248(01)01623-2
  3. K. Kakimoto, "Oxygen distribution in silicon melt under inhomogeneous transverse-magnetic fields", J. Crystal Growth 230 (2001) 100 https://doi.org/10.1016/S0022-0248(01)01315-X
  4. K. Hoshikawa and X. Huang, "Oxygen transportation during Czochralski silicon crystal growth", Mater. Sci. Eng B 72 (2000) 73 https://doi.org/10.1016/S0921-5107(99)00494-8
  5. M. Watanabe, M. Eguchi and T. Hibiya, "Flow and temperature field in molten silicon during Czochralski crystal growth in a cusp magnetic field", J. Crystal Growth 193 (1998) 402 https://doi.org/10.1016/S0022-0248(98)00529-6
  6. K. Nakamura, S. Maeda, S. Togawa, T. Saishoji and J. Tomioka, "Effect of the shape of crystal-melt interface on point defect reaction in silicon crystals", ECS Proceeding 17 (2000)31
  7. B.C. Sim, Y.H. Jung, J.E. Lee and H.W. Lee. "Effect of the crystal-melt interface on the grown-in defects in silicon CZ growth", J Crystal Growth, 299 (2007) 152 https://doi.org/10.1016/j.jcrysgro.2006.11.217
  8. D. Vizman, M. Watanabe, J. Friedrich and G. Muller, "Influence of different types of magnetic fields on the interface shape in a 200 mm Si-EMCZ configuration", J. Crystal Growth 303 (2007) 221 https://doi.org/10.1016/j.jcrysgro.2006.11.347
  9. Y.H. Hong, B.C. Sim and K.B. Shim, "Effect of zero-Gauss plane and magnetic intensity on oxygen concentration in cusp-magnetic CZ crystals", J Crystal Growth 295 (2006) 141 https://doi.org/10.1016/j.jcrysgro.2006.06.044
  10. Y.H. Hong, B.C. Sim and K.B. Shim, "Distribution coefficient of boron in Si crystal ingots grown in cuspmagnetic Czochralski process", J. Crystal Growth 310 (2008) 83 https://doi.org/10.1016/j.jcrysgro.2007.10.015
  11. V. Galindo, G. Gerbeth, W. von Ammon, E. Tomzig and J. Virbulis, "Crystal growth melt flow control by means of magnetic fields", Energy Conversion Manage. 43 (2002) 309 https://doi.org/10.1016/S0196-8904(01)00100-5
  12. D. Vizman O. Grabner and G. Muller, "Three dimensional numerical simulation of thermal convection in an industrial Czochralski melt: comparison to experimental results", J. Crystal Growth 233 (2001) 687 https://doi.org/10.1016/S0022-0248(01)01633-5