Combined effects of sample parameters on polymer charging due to electron irradiation: A contour simulation

• Electron-induced polymer charging is described by contour maps for the first time.
• Leakage current and surface potential are highly correlated in contour features.
• The total charge has the local maximum with respect to sample thickness.
• Sample thickness normally affects charging effects more than electron mobility.

Combined effects of sample parameters on polymer charging due to electron irradiation are explored by a novel approach of contour in parallel computing. Transient processes of negative charging of a Kapton film sample irradiated by 10 keV electrons are simulated with a simultaneous scattering-transport model and the existing experimental secondary electron current. As a function of sample thickness and electron mobility, the contour maps are then presented of the steady-state leakage current and surface potential and the total charge accumulated in a charging process. It is found that the leakage current and surface potential behave similarly in the contour form, and the total charge has the local maximum with respect to the sample thickness. Generally, the sample thickness affects the charging process more than the electron mobility, but both have less influence in very strong and weak charging states. Accompanied by discussion of charge dissipation effects, this study offers a comprehensive insight into complicated charging phenomena in electron-based surface microscopy, analysis and measurement.