Conceptual models for understanding and minimizing Coulomb interactions

Abstract The purpose of this paper is to investigate Coulomb interaction and their impact on practical column design. The phenomena of electron-electron interaction in charged particle systems is not a new topic, for a complete discussion of the history and the many theoretical models see [Jansen (1990)]; however most of the effort has been towards devising theoretical models and fast computer techniques, which the designer can then used to evaluate his own column design. The approach is excellent for individual column evaluations but does not give the designer good practical guidelines to minimize these effects. Therefore, there is a need to analyze simple physical models to gain insight into column design. In this paper the Monte Carlo technique will be used to analyze simple electron optical systems, providing the designer intuitive guidelines. The Monte Carlo technique is best suited for this investigation because is minimizes the number of basic assumptions. From the evaluation of these simple physical models a set of design rules will be given. In addition these design rules have been used to evaluate an electron beam inspection system of X-ray masks.