The trend toward smaller dimensions in integrated circuit technology presents severe physical and engineering challenges for ion implantation. These challenges, together with the need for physically-based models at exceedingly small dimensions, are leading to a new level of understanding of fundamental defect science in silicon. Recently the DOE Council on Materials requested that our panel examine the current status and future research opportunities in the area of ion beams in semiconductor processing. Particularly interesting are the emerging approaches to defect and dopant distribution modeling, transient enhanced diffusion, high energy implantation and defect accumulation, and metal impurity gettering. These topics were explored both from the perspective of the emerk&g science issues and the technolou challenges.Ion implantation is one of the most important processing tools in Si integrated circuit technolo=. However, in the move to ever finer dimensions real physical and en_&eering limits are being confronted (see Table I for the Semiconductor Industry Association projections for future device dimensions). For.example, in low energy implantation for shallow junction formation, understanding and controlling defect enhanced diffusion are becoming critical factors in building in the needed dimensional control for circuit design. A panel study commissioned by the U.S. Department of Energy Council on Materials addressed these and other fundamental science and technology issues confronting the semiconductor processing industry in the area of ion beam processing [2]. We briefly summarize those results here. phenomena and the incorporation of this understanding into realistic computer-based models. Coupled with these critical needs in the understanding of the basic processes are the challenges for future commercial machine development in the very low energy and the high energ re, @mes. In addition, focused ion beams are becoming increasingly important, for example in mask repair, while their role in implantation and lithography is still uncertain.In Fig. 1 we illustrate m&y of the key steps where ion implantation is used in the manufacturing of complementary'metal oxide semiconductor (CMOS) technology. Typically 15 or more implantations will be carried out in the course of some 300 or more steps in the