Strain mapping in selected area electron diffraction method combining a Cs-corrected TEM with a stage scanning system

Abstract

A novel strain mapping method with high spatial resolution is proposed on the basis of the selected area electron diffraction. It consists of a Cs-corrected transmission electron microscope (TEM) and a stage scanning system. The Cs-corrected TEM sufficiently narrows a selected area aperture without image selection error and enables us to obtain diffraction patterns from selected nanometer-scale regions with a parallel beam. The diffraction spots are very sharp due to the parallel beam, thus facilitating the strain measurement. The stage scanning system for controlling the sample stage with piezoelectric actuators can scan an electron beam over an area without changing the electron beam optics. I critically examined the validity and flexibility of this method by using a current strain-induced semiconductor device.