Computer simulations analysis for determining the polarity of charge generated by high energy electron irradiation of a thin film

• Published in: Micron (Oxford, England : 1993) Vol. 100; pp. 10 - 22
• Main Authors: Malac, Marek, Hettler, Simon, Hayashida, Misa, Kawasaki, Masahiro, Konyuba, Yuji, Okura, Yoshi, Iijima, Hirofumi, Ishikawa, Isamu, Beleggia, Marco
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-09-2017
• Subjects: Electron beam induced charging; Fresnel images; Hole-free phase plate; Radiation damage; Thon rings; Volta phase plate; Volta phase plate; Fresnel images; Electron beam induced charging; Radiation damage; Hole-free phase plate; Thon rings
• ISSN: 0968-4328; 1878-4291
• DOI: 10.1016/j.micron.2017.03.015

•Guide for the determination of charge polarity of an electron beam irradiated thin film.•A Scherzer-like band appears in the power spectrum of phase plate images when the sign of defocus opposes the sign of the phase plate phase shift.•Optimization of the imaging condition with hole-free phase plates.
Detailed simulations are necessary to correctly interpret the charge polarity of electron beam irradiated thin film patch. Relying on systematic simulations we provide guidelines and movies to interpret experimentally the polarity of the charged area, to be understood as the sign of the electrostatic potential developed under the beam with reference to a ground electrode. We discuss the two methods most frequently used to assess charge polarity: Fresnel imaging of the irradiated area and Thon rings analysis. We also briefly discuss parameter optimization for hole free phase plate (HFPP) imaging. Our results are particularly relevant to understanding contrast of hole-free phase plate imaging and Berriman effect.