Understanding the phase images from off-axis electron holography

Abstract

The exceptional stability of the latest generation of electron microscopes has allowed off-axis electron holography to become a relatively straightforward technique to perform experimentally. In addition, focused ion beam milling can be used to prepare a thin TEM specimens that contain an individual devices with nm-scale site specificity. Although phase images FIB-prepared semiconductor devices can be reconstructed with excellent signal to noise ratios, quantification of these phase profiles remains problematic due to the artefacts that are introduced into the specimens during FIB preparation. In this paper we discuss the physical reasons for these artefacts and suggest strategies for removing them. © 2009 American Institute of Physics.