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Improved Focused Ion Beam Target Preparation of (S)TEM Specimen—A Method for Obtaining Ultrathin Lamellae

Published online by Cambridge University Press:  21 March 2012

Lorenz Lechner*
Affiliation:
Center for Electron Microscopy, Materials Science Group, Ulm University, Ulm, Germany
Johannes Biskupek
Affiliation:
Center for Electron Microscopy, Materials Science Group, Ulm University, Ulm, Germany
Ute Kaiser
Affiliation:
Center for Electron Microscopy, Materials Science Group, Ulm University, Ulm, Germany
*
Corresponding author. E-mail: [email protected]
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Abstract

Specimen quality is vital to (scanning) transmission electron microscopy (TEM) investigations. In particular, thin specimens are required to obtain excellent high-resolution TEM images. Conventional focused ion beam (FIB) preparation methods cannot be employed to reliably create high quality specimens much thinner than 20 nm. We have developed a method for in situ target preparation of ultrathin TEM lamellae by FIB milling. With this method we are able to routinely obtain large area lamellae with coplanar faces, thinner than 10 nm. The resulting specimens are suitable for low kV TEM as well as scanning TEM. We have demonstrated atomic resolution by Cs-corrected high-resolution TEM at 20 kV on a FIB milled Si specimen only 4 nm thick; its amorphous layer measuring less than 1 nm in total.

Type
Techniques and Software Development
Copyright
Copyright © Microscopy Society of America 2012

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