ELIMINATION OF THICKNESS DEPENDENCE FROM MEDIUM RESOLUTION ELECTRON HOLOGRAMS

We show that a composition image that is independent of thickness can be obtained by suitably combining the phase and amplitude images extracted from an off-axis electron hologram. This image is the product of the mean inner potential of the material and the mean-free-path for inelastic scattering. The method used has been evaluated using single crystal Si wedges with known linearly increasing thickness, and it has then been applied to CoSi2/Si epitaxial interfaces with unknown thickness. Thickness independent images of Si show constant contrast while images of hetero interface emphasize compositional differences.