Depth Sectioning of Aligned Crystals with the Aberration-Corrected Scanning Transmisstion Electron Microscope
- ORNL
- Harding University, Searcy, AR
The implementation of aberration correction for the scanning transmission electron microscope (STEM) enables the use of larger probe-forming apertures, improving the transverse resolution significantly and also bringing depth resolution at the nanometer scale. This opens up the possibility of three-dimensional imaging by optical sectioning, and nanometer-scale depth resolution has been demonstrated for amorphous and off-axis samples. For crystalline materials it is usual to image in a zone axis orientation to achieve atomic resolution. In this case, the tendency for the beam to channel along the columns complicates the simple optical sectioning technique. Here we conduct a series of simulations which demonstrate that higher beam convergence angles available in next generation aberration correctors can overcome this limitation. Detailed simulations with realistic values for residual aberrations predict nanometer-scale depth resolution for Bi dopant atoms in Si (110) for an instrument corrected up to fifth order. Use of a monochromator appears to significantly improve the depth resolution.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 1003567
- Journal Information:
- Journal of Electron Microscopy, Vol. 55, Issue 1; ISSN 0022--0744
- Country of Publication:
- United States
- Language:
- English
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