INSULATOR SURFACE-ANALYSIS

The purpose of this article is to show how the study of the electrostatic charge deposited in a dielectric material by an electron beam allows one to characterize its mechanical and electrical properties. A theoretical approach to the charging phenomenon is first proposed, based on the self-trapping of electrons in a dielectric medium (polaron). Then a destabilization process of the charge followed by the relaxation of the polarization energy stored in the material is proposed to account for the initiation of breakdown. In a third part, the experimental mirror method which allows one to study the implanted charge is described and, finally, applications of the method to the characterization of breakdown voltages of oxides and polymers and of mechanical properties of ceramics are developed.