INTERPRETABLE RESOLUTION OF 0.2 NM AT 100 KV USING ELECTRON HOLOGRAPHY

Knowledge of amplitude and phase of the image wave is fundamental for numerical correction of the wave aberration. Therefore, off-axis elect ron holography provides a technique that could substantially improve t he point resolution of an electron microscope. Correction for spherica l aberration as well as choice of the appropriate defocus pushes the i nterpretable resolution towards the information limit. Using a thin am orphous germanium specimen covered with a very small amount of platinu m, we measured the information limit of our Philips EM420ST FEG to be 0.17 nm at 100 kV. Thin amorphous tungsten foil was used to demonstrat e the feasibility of the correction for coherent aberrations up to a s patial frequency of 5 nm(-1), which is a major improvement compared to 3.1 nm(-1) Scherzer resolution.