Formation of iron impurity clusters in silicon

Abstract

This article discusses the formation of impurity clusters in the bulk of single-crystal silicon doped with iron using high-temperature diffusion. Schematic models of the formation sequence of spherical, needle-shaped, and lenticular impurity clusters in the bulk of iron-doped n-type silicon samples are also presented. It was revealed that the quantitative fraction of iron atoms (by mass) in the volume of single-layer impurity clusters reaches about 50%, which corresponds to iron silicide FeSi2. In contrast, in the bulk of bilayer clusters, this value in the inner layer reaches about 66.5%, and it corresponds to iron silicide FeSi. And in the outer layer of such impurity clusters, the quantitative fraction of iron atoms is about 50%.