Lateral spread of damage formed by ion implantation

Abstract

The lateral distribution of damage introduced in semiconductors by ion implantation is studied theoretically using the theory of Lindhard et al. This theoretical study is experimentally verified by a backscattering measurement of the damage formed by ion implantation into a tilted target. It is found that the spread of lateral damage is largest at a position near to or deeper than the ion projected range, and that the ratio of the lateral damage spread from a mask edge to the longitudinal damage spread from the surface is less than unity even in the case of implantation of light ions. For instance, the ratio is about 20% in the case of 100‐keV B⁺ implantation into Si. It is also found that the ratio becomes smaller as the energy of the implanted ions increases or as the ions become heavier.