Ion sources can be used for a variety of applications in thin film deposition and etching. For example, they can be used for substrate pre-cleaning, reactive deposition of oxide and nitrides (ion beam assisted deposition), and ion beam milling. When selecting and designing a deposition system that uses an ion source, many factors come into play. Some design features are dictated by the application, and some can be balanced against cost and performance. Below are five factors to keep in mind as you select an ion beam source.