Space Charge in Irradiated Insulators: Mirror Method

Abstract

A scanning electron microscope mirror method analysis has been developed to study the geometry of the trapped charge distribution within irradiated insulators. Several authors have noted that the optical geometrical approximation is an appropriate model to illustrate the mirror image formation. Nevertheless, some results have shown that it is not possible to use such model in the case of anisotropic material in which we can observe an elliptic mirror image. In this paper, we propose a new theoretical model to explain the formation of such elliptic mirror, which confirms the electric charge delocalization.

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

“…The above argument is valid only for normal use of a SEM to imaging conductive, or either a metal-coated insulator, samples. However, when a sample of a dielectric material (or either not grounded conducting sample) is adopted for inspection by means of the SEM, the mirror effects occur inside the SEM chamber, see for example [16,10].…”

“…The above argument is valid only for normal use of a SEM to imaging conductive, or either a metal-coated insulator, samples. However, when a sample of a dielectric material (or either not grounded conducting sample) is adopted for inspection by means of the SEM, the mirror effects occur inside the SEM chamber, see for example [16,10].Substantially, this phenomenon arises due to the accumulation of charges, electrons in the SEM [2] and ions in Focused Ion Beams FIB [8], at the sample surface during the irradiation process. Consequently, an electric potential will be born and begins to growth over the irradiated region up to the state of saturation [1].…”

The Beam Current Considerations in SEM Accordance to Mirror Effect Phenomenon

“…However, when a sample for a dielectric material (or either not grounded conducting sample) is adopted for inspection by means of SEM or FIB, the mirror effect come to be occurs inside the SEM chamber, see for example the references [5] and [6].…”