Ion implantation in semiconductors—Part II: Damage production and annealing

Abstract

Radiation damage is produced in a crystalline target whenever a moving ion transfers sufficient energy to a target atom to displace it from its lattice site. For conditions of practical importance in ion implantation, the radiation damage produced by the injected ions is severe, and the crystal must be carefully Annealed if the chemical effects of the implanted ions are to dominate the residual damage. The purpose of this paper is to review work that has been performed over the past several years in an effort to understand implantation-produced damage and its annealing characteristics, especially in silicon. The subject is developed as follows. A qualitative description of the damage produced by an implanted ion is presented in Section I, followed by a partial inventory of the basic defects that are found in ion-implanted silicon (Section II). The structure of individual damage clusters produced by both heavy and light ions is then described in Section III, where theoretical predictions are compared to a variety of experimental data. This is followed with a section on the depth distribution of defects and damage clusters (Section IV); and the paper is then concluded with a section on the annealing characteristics of implantation-produced damage (Section V). The development is organized to give primary emphasis to those facts and ideas that are essential for applications of ion implantation in the fabrication of MOS and junction devices in silicon. A future paper will review the state of the art in compound semiconductors.