RECENT DEVELOPMENTS IN ION-IMPLANTATION ACCELERATORS

Ion implantation technology plays an important role in different fields of materials modification and has become a well established industrial technique. In semiconductor device fabrication more than 1000 ion implanters operating in the low- and medium-energy range (≤, 400 keV) are working worldwide. There is also an increasing interest in the improvement of the surface properties of metals, ceramics, and polymers by means of ion implantation. For some of the newer applications the required penetration depth is large, up to several μm, corresponding to an ion beam energy of several MeV. Furthermore, certain processes involve implant doses up to 1018 ions/cm2, which implies that high currents are needed as well. Both requirements - high ion current and high energy - are difficult to fulfill simultaneously by the commonly used static machines. Modem rf linacs combine strong radial focusing with efficient acceleration, which allows for high currents and high energy. In this paper recent developments in this field will be discussed. © 1990.