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Scanning Confocal Electron Energy-Loss Microscopy Using Valence-Loss Signals

Published online by Cambridge University Press:  22 May 2013

Huolin L. Xin*
Affiliation:
Materials Sciences Division, Lawrence Berkeley National Lab, Berkeley, CA 94720, USA
Christian Dwyer
Affiliation:
Monash Centre for Electron Microscopy, ARC Centre of Excellence for Design in Light Metals, Department of Materials Engineering, Monash University, Clayton, Vic. 3800, Australia
David A. Muller
Affiliation:
School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14850, USA Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY 14850, USA
Haimei Zheng
Affiliation:
Materials Sciences Division, Lawrence Berkeley National Lab, Berkeley, CA 94720, USA
Peter Ercius*
Affiliation:
National Center for Electron Microscopy, Lawrence Berkeley National Lab, Berkeley, CA 94720, USA
*
*Corresponding author. E-mail: hxin@lbl.gov
**Corresponding author. E-mail: percius@lbl.gov
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Abstract

Finding a faster alternative to tilt-series electron tomography is critical for rapidly evolving fields such as the semiconductor industry, where failure analysis could greatly benefit from higher throughput. We present a theoretical and experimental evaluation of scanning confocal electron energy-loss microscopy (SCEELM) using valence-loss signals, which is a promising technique for the reliable reconstruction of materials with sub-10-nm resolution. Such a confocal geometry transfers information from the focused portion of the electron beam and enables rapid three-dimensional (3D) reconstruction by depth sectioning. SCEELM can minimize or eliminate the missing-information cone and the elongation problem that are associated with other depth-sectioning image techniques in a transmission electron microscope. Valence-loss SCEELM data acquisition is an order of magnitude faster and requires little postprocessing compared with tilt-series electron tomography. With postspecimen chromatic aberration (Cc) correction, SCEELM signals can be acquired in parallel in the direction of energy dispersion with the aid of a physical pinhole. This increases the efficiency by 10×–100×, and can provide 3D resolved chemical information for multiple core-loss signals simultaneously.

Type
Materials Applications
Copyright
Copyright © Microscopy Society of America 2013 

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