Lensless electron reflection microscopy using a coaxial point-source structure

A lensless image of the surface of a crystal is obtained by the reflection on this surface of a low-energy electron beam originated from a point source integrated in a coaxial structure. The point source is a sharp field emission tip and a free propagation of reflected electrons results from the shielding of the tip voltage provided by the coaxial structure. Images are obtained for an incidence angle between 3 and 45° and for nA incident currents with a kinetic energy down to 40 V. On silicon surfaces a magnification up to a few thousands and a spatial resolution of 100 nm are demonstrated.