Transient enhanced diffusion of dopants in silicon induced by implantation damage

Abstract

The effects of implantation damage on B, P, As, and Sb diffusion in Si during rapid thermal annealing and conventional heat treatment at low temperature (750–900 °C) have been investigated. Comparison of dopant profiles and junction depths in damaged and undamaged regions demonstrates that a Si+ implantation in the typical conditions used for preamorphization in p+/n shallow junction fabrication, produces a markedly enhanced diffusion for B and P atoms, while inducing only a negligible increase of As and Sb diffusivity. For all dopants enhanced diffusion shows a transient behavior and produces an increase in junction depth which is higher the lower the annealing temperature. This corroborates the opinion that rapid thermal annealing is a suitable technique for shallow junction fabrication.