Simulation of ion beam induced micro/nano fabrication

Abstract

The shrinking critical dimensions of modern technology place heavy requirements on optimizing feature shapes at the micro and nano scale. Ion beams are increasingly used for technology development in the nano-scale world. In recent years, many approaches and research results have indicated that re-deposition of sputtered target atoms is the most serious problem in fabricating micro and nano devices. A simulation tool is essential to reduce unnecessary time and efforts spent in process development. In this paper, we present two-dimensional string-based simulation software for ion milling and focused ion beam direct fabrication, AMADEUS-2D (advanced modeling and design environment for sputter processes). We discuss the numerical model for considering sputtering and re-deposition fluxes. In addition, we investigate sputtering yield and sputtered atom distributions as obtained from several binary collision simulation codes. The newly developed simulation code is validated by comparison with experimental data on single-pixel hole milling, on the width and dose dependence of trench formation and on the effective sputtering yield as a function of scan speed.