Applied Microscopy

  • 제38권4호
  • /
  • Pages.363-374
  • /
  • 2008
  • /
  • 2287-5123(pISSN)
  • /
  • 2287-4445(eISSN)
한국현미경학회 (Korean Society of Microscopy)
권호 표지

비교적 두꺼운 결정으로부터 얻은 일련의 비 초점 단계의 고전압 HRTEM 영상들에 대한 IWFR 분석의 유용성 실험

Experiment of Usefulness of IWFR Analysis for High Voltage HRTEM Images with a Series of Defocus Steps Obtained from a Relatively Thick Crystal

  • 오상호 (한국기초과학지원연구원 전자현미경연구부) ;
  • 김윤중 (한국기초과학지원연구원 전자현미경연구부) ;
  • 김황수 (경성대학교 이과대학 물리학과)
  • Oh, Sang-Ho (Division of Electron Microscopic Research, Korea Science Institute) ;
  • Kim, Youn-Joong (Division of Electron Microscopic Research, Korea Science Institute) ;
  • Kim, Hwang-Su (Department of Physics, Kyungsung University)
  • 발행 : 2008.12.31
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

이 논문에서는 비교적 두꺼운 결정에 대한 일련의 고 분해 영상들에 대한 IWFR 분석의 유용성을 실험하였다. 이를 위해 JEOL ARM 1300S를 이용하여 실리콘 결정의 30 nm 두께의 [01-1] 방위와 35 nm 두께의 [11-2]에 대한 일련의 비 초점 단계의 고 분해 영상들을 관찰하였다. 이로부터 두꺼운 시료에 대해서도 IWFR 분석 결과로부터 결정 밑 표면의 파동함수를 얻을 수 있음이 밝혀졌다. 그러나 강한 동역학적 산란에 의한 효과 때문에, 이 함수의 영상패턴은 시료의 원자열 구조의 패턴을 다만 정성적으로만 반영하고 있다. 그럼에도 불구하고 이 패턴은 결정구조의 중요한 단서를 제공할 것임은 의심의 여지가 없다

In this paper we have examined the usefulness of IWFR (the iterative wave-function reconstruction) analysis for through-focal series of high-resolution images for a relative thick crystal. In the work we employed JEOL ARM 1300S, and observed the high-resolution images for a Si crystal at the two orientations of [01-1] and [11-2] having 30 nm and 35 nm thickness respectively. As a result of applying IWFR method on the images we found out that even for a thick crystal by the method we can retrieve the exit-surface wave function. However because of the strong dynamical scattering effect, the image pattern of the function reflects only qualitatively the atomic column structure of the crystal examined. Nevertheless it is no doubt that the pattern would give important clue for the crystal structure.

키워드

참고문헌

  1. Allen LJ, McBridge W, O'Leary NL, Oxley MP: Exit wave reconstruction at atomic resolution. Ultramicroscopy 100 : 91-104, 2004 https://doi.org/10.1016/j.ultramic.2004.01.012
  2. Allen LJ, Oxley MP, Ishizuka K: Electron microscope $C_s$ correction using iterative wave-function reconstruction. Microscopy and Analysis 52 : 5-7, 2006
  3. Chang LY, Kirkland AI: Comparisons of linear and nonlinear image restoration. Microsc Microanal 12 : 469-475, 2006 https://doi.org/10.1017/S1431927606060582
  4. Coene W, Janssen G, Op de Beeck M, Van Dyck D: Phase retrieval through focus variation for ultra-resolution in field-emission transmission electron microscopy. Phys Rev Lett 69 : 3743-3746, 1992 https://doi.org/10.1103/PhysRevLett.69.3743
  5. Coene WMJ, Thust A, Op de Beeck M, Van Dyck D: Maximumlikelihood method for focus-variation image reconstruction in high resolution transmission microscopy. Ultramicroscopy 64: 109-135, 1996 https://doi.org/10.1016/0304-3991(96)00010-1
  6. Kim HS: A Review of IWFR method for HRTEM image analysis and application. Korean J Microscopy 38(1) : 63-72, 2008. (Korean)
  7. Kim HS: Effects of higher-order Laue zone reflections on HRTEM images for illumination along an off-zone axis of a crystal. Korean J Electron Microscopy 37(4): 259-269, 2007. (Korean)
  8. Kim JG, Kang SK, Kim WC, Kim YJ: Three-dimensional structure analysis of $SmZn_{0.67}Sb_2$ by transmission electron microscopy. Korean J Electron Microscopy 34(4) : 255-264, 2004. (Korean)
  9. Kisielowski C, Hetherington CJD, Wang YC, Kilaas R, O'Keefe MA, Thust A: Imaging columns of the light elements carbon, nitrogen and oxygen with sub angstrom resolution. Ultramicroscopy 89 : 243-263, 2001 https://doi.org/10.1016/S0304-3991(01)00090-0
  10. Spence JCH: Experimental high resolution electron microscopy. Oxford Univ Press, Oxford, 1981
  11. Tillmann K, Thust A, Urban K: Spherical aberration correction in tandem with exit-plane wave function reconstruction: Interlocking tools for the atomic scale imaging of lattice defects in GaAs. Micros Microanal. 10 : 185-198, 2004 https://doi.org/10.1017/S1431927604040395
  12. Voelkl E, Jiang B, Dai ZR, Bradley JP: Improving image quality and reducing drift problem via automated data acquisition and averaging in a $C_s$-corrected TEM. Microscopy Today 16(6) : 36-38, 2008