2002 Volume 43 Issue 3 Pages 474-477
The charging effect due to the electron irradiation in spherical SiO2 particles of 250 nm in diameter has been analyzed by electron holography. Electron holograms of a charged SiO2 particle on the side surface of the carbon film were simulated taking into account the electric shielding effect due to the carbon film. In order to compare the observed hologram and the simulated holograms quantitatively, the residual index between the observed and simulated images was evaluated. Through the quantitative analysis taking into account the shielding effect with the limited side surface area of the carbon film, the amount of the charge was evaluated to be 3.38×10−17 C for the current density of incident electron beam at 0.24 A/m2 without an objective aperture.