Secondary electron count imaging in SEM
Files
Accepted manuscript
Date
2023-03
Authors
Agarwal, Akshay
Simonaitis, John
Goyal, Vivek K.
Berggren, Karl K.
Version
Accepted manuscript
OA Version
Citation
A. Agarwal, J. Simonaitis, V.K. Goyal, K.K. Berggren. 2023. "Secondary electron count imaging in SEM." Ultramicroscopy, Volume 245, pp.113662-. https://doi.org/10.1016/j.ultramic.2022.113662
Abstract
Scanning electron microscopy (SEM) is a versatile technique used to image samples at the nanoscale. Conventional imaging by this technique relies on finding the average intensity of the signal generated on a detector by secondary electrons (SEs) emitted from the sample and is subject to noise due to variations in the voltage signal from the detector. This noise can result in degradation of the SEM image quality for a given imaging dose. SE count imaging, which uses the direct count of SEs detected from the sample instead of the average signal intensity, would overcome this limitation and lead to improvement in SEM image quality. In this paper, we implement an SE count imaging scheme by synchronously outcoupling the detector and beam scan signals from the microscope and using custom code to count detected SEs. We demonstrate a ∼30% increase in the image signal-to-noise-ratio due to SE counting compared to conventional imaging. The only external hardware requirement for this imaging scheme is an oscilloscope fast enough to accurately sample the detector signal for SE counting, making the scheme easily implementable on any SEM.
Description
License
© 2022 Elsevier B.V. All rights reserved. This preprint version of the article is available under the CC BY-NC-ND license.