Anomalous transient diffusion of ion implanted dopants: A phenomenological model

Abstract

The reduced thermal budget required for very shallow p/n junctions gives greater significance to some of the previously ignored effects occurring during the anneal of ion implanted layers. The anomalous transient displacement that is observed for some dopants during high temperature, short time anneals is a major contribution to the junction depth. The experimental evidence supports a model for the transient displacement that involves the evolution of the damage created by the implanted ions. It is thermal dissolution of small clusters of interstitial silicon atoms created by the ion implantation that produces a supersaturation of interstitial silicon atoms which is the basic cause of the anomalous transient displacement. The formation of extended defects also plays an important role in the redistribution and activation of the dopant. © 1989.