Introduction to focused ion beams, ion sources, and the nano-aperture ion source

In this chapter the basics of focused ion beam (FIB) systems are summarized and the nano-aperture ion source (NAIS) is introduced. First a brief overview of ion-surface interactions and their applications is given. Next, the most important optical aspects of FIB systems are discussed and a comparison of different ion sources is made. After this discussion of focused ion beams in a general context, the nano-aperture ion source is introduced. A basic theoretical model from which estimates of the performance can be made is derived. In addition, an optimization for the required electron column is discussed. The basic model in combination with the electron beam optimization is used to acquire performance estimates of the NAIS.