Characterization of charge trapping in insulating films by a scanning electron microscope

An electrostatic model has been developed to describe the mirror image formation in the scanning electron microscope mirror method and to calculate the trapping ability by using a semi-infinite sample. However, some results have shown that it is not possible to use this simple model in the case of film insulators. Thus, in this article, we propose an analysis of the electrostatic potential, including image charge effects, to calculate the trapping ability of films. The theoretical expression of the mirror curves is compared to experimental results on polymer films having a minimum thickness of 35 μm.