This study demonstrates the accumulation of electron-induced secondary electrons by utilizing a simple geometrical configuration of two branches of a charged insulating biomaterial. The collective motion of these secondary electrons between the branches has been visualized by analyzing the reconstructed amplitude images obtained using in situ electron holography. In order to understand the collective motion of secondary electrons, the trajectories of these electrons around the branches have also been simulated by taking into account the electric field around the charged branches on the basis of Maxwell’s equations.

The relation between probe size and spatial resolution of backscattered electron (BSE) images was studied. In addition, the effect of the accelerating voltage, the current intensity and the sample geometry and composition were analyzed. An image synthesis method was developed to generate the images from backscattered electron coefficients obtained from Monte Carlo simulations. Spatial resolutions of simulated images were determined with the SMART-J method, which is based on the Fourier transform of the image. The resolution can be improved by either increasing the signal or decreasing the noise of the backscattered electron image. The analyses demonstrate that using a probe size smaller than the size of the observed object (sample features) does not improve the spatial resolution. For a probe size larger than the feature size, the spatial resolution is proportional to the probe size.

The process of electron-beam-induced deposition (EBID) was simulated with a dynamic Monte Carlo profile simulator, and the growth of carbon, silver, and tungsten supertips was investigated to study the dependence of material composition on the spatial resolution of EBID. Because light atoms have a smaller scattering angle and a longer mean free path, the carbon supertip has the smallest lateral size and the highest aspect ratio of a bottom tip compared to silver and tungsten supertips. Thus the best spatial resolution of EBID can be achieved on materials of low atomic number. The calculation also indicated a significant contribution of primary electrons to the growth of a supertip in EBID, which is consistent with the experimental observations. These results lead to a more comprehensive understanding of EBID, which is a complex interaction process between electrons and solids.