TY - JOUR
T1 - Depth sectioning of aligned crystal with the aberration-corrected scanning transmission electron microscope
AU - Borisevich, Albina Y.
AU - Lupini, Andrew R.
AU - Travaglini, Samuel
AU - Pennycook, Stephen J.
PY - 2006/1
Y1 - 2006/1
N2 - 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.
AB - 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.
KW - Aberration correction
KW - Depth sectioning
KW - Electron channeling
KW - Scanning transmission electron microscopy
UR - http://www.scopus.com/inward/record.url?scp=33646750094&partnerID=8YFLogxK
U2 - 10.1093/jmicro/dfi075
DO - 10.1093/jmicro/dfi075
M3 - Article
AN - SCOPUS:33646750094
SN - 0022-0744
VL - 55
SP - 7
EP - 12
JO - Journal of Electron Microscopy
JF - Journal of Electron Microscopy
IS - 1
ER -