Beam analysis of scanning electron microscope according to the mirror effect phenomenon

• A theoretical approach for investigates and understands electron mirror images are presented.
• The beam, surface and accelerating potentials are expressed in single mathematical formula.
• It is found that assumption of uniform distribution of electrons in a beam surface is reasonable.
• The influence of beam and sample parameters on electron mirror images are defined.
• The presented approach can be used to calculate the trapped charges.

In a scanning electron microscope the influence of electronic beam parameters on the electron-mirror images has been investigated. A simple theoretical model for scanning electron beam behavior in terms of beam and surface potentials is presented. The derived expression relates the scanning beam parameters and parameters of an irradiation region. Influence of a beam (the size and current), scanning potential, working distance, trapped charge and the irradiated area on electron mirror images are defined. Results show that the electron beam current has a considerable effect on the deduced mirror images in comparison with the other beam parameters. So it could be adapted for adjusting the phenomena of mirror effect. Moreover, the trapped charges have been calculated and the results examined in comparison with experimental data.