A Monte Carlo simulation study on the image resolution in scanning electron microscopy

The resolution of the scanning electron microscope limited by the beam-sample interaction is studied by Monte Carlo simulation. The simulation model is based on the full Penn algorithm for electron inelastic scattering and the associated secondary electron generation as well as on a constructive solid geometry modeling of a complex sample structure. The line-scan profiles for gold nanoparticles of different diameters on a carbon substrate are obtained in the simulation. The gap method and contrast-to-gradient (C-G) method performed for two separated particles of the same size and different sizes are considered to determine the resolution. Both methods are applied to the simulated images. A comparison on the obtained resolutions performed for the different sample topographies shows that the gap resolution depends excessively on the topography by the shading effect and gap method underestimates the influence of probe size, while C-G method overestimates this influence. Copyright (C) 2010 John Wiley & Sons, Ltd.