description of the main trends in the field. The second chapter is devoted to ion im­ planters, including also high energy apparatus and a description of wafer charging and contaminants. Yield is a quite relevant is­ sue in the industrial surrounding and must be also discussed in the academic ambient. The slowing down of ions is treated in the third chapter both analytically and by numerical simulation meth­ ods. Channeling implants are described in some details in view of their relevance at the zero degree implants and of the available industrial parallel beam systems. Damage and its annealing are the key processes in ion implantation. Chapter four and five are dedicated to this extremely important subject.