Issue |
MATEC Web of Conferences
Volume 32, 2015
International Symposium of Optomechatronics Technology (ISOT 2015)
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Article Number | 05003 | |
Number of page(s) | 6 | |
Section | Progress in microscopy and imaging | |
DOI | https://doi.org/10.1051/matecconf/20153205003 | |
Published online | 02 December 2015 |
Closed-Loop Autofocus Scheme for Scanning Electron Microscope
1 Université de Rennes 1, Lagadic team, IRISA, Rennes, France
2 AS2M department, FEMTO-ST institute, Besançon, France
a e-mail: le.cui@univ-rennes1.fr
In this paper, we present a full scale autofocus approach for scanning electron microscope (SEM). The optimal focus (in-focus) position of the microscope is achieved by maximizing the image sharpness using a vision-based closed-loop control scheme. An iterative optimization algorithm has been designed using the sharpness score derived from image gradient information. The proposed method has been implemented and validated using a tungsten gun SEM at various experimental conditions like varying raster scan speed, magnification at real-time. We demonstrate that the proposed autofocus technique is accurate, robust and fast.
© Owned by the authors, published by EDP Sciences, 2015
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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