Beam shaping and probe characterization in the scanning electron microscope

Ultramicroscopy. 2021 Jun:225:113268. doi: 10.1016/j.ultramic.2021.113268. Epub 2021 Apr 3.

Abstract

Here we demonstrate the use of nanofabricated grating holograms to diffract and shape electrons in a scanning electron microscope. The diffraction grating is placed in an aperture in the column. The entire diffraction pattern can be passed through the objective lens and projected onto the specimen, or an intermediate aperture can be used to select particular diffracted beams. We discuss several techniques for characterizing the diffraction pattern. The grating designs can incorporate features that can influence the phase and intensity of the diffracted SEM probe. We demonstrate this by producing electron vortex beams.

Keywords: Electron beam structuring; Electron diffraction; Electron vortex beam; SEM; Spot shape measurement.