Temperature and Time Dependence of Dopant Enhanced Diffusion in Self‐Ion Implanted Silicon

Abstract

Diffusion experiments for boron, phosphorus, arsenic, and antimony were performed in the presence of lattice defects produced by silicon ion implantation. The effects of transient enhanced diffusion were revealed by beveling and staining measurements on selectively implanted samples and by SIMS determinations of dopant profiles. The annealing of the doped implanted specimens ranged from 700° to 1100°C, the last treatment having been made by electron beam. The low temperatures allowed the following of the kinetics of the anomalous diffusion: it was ascertained that the enhanced diffusion coefficient is nearly constant until a time value is reached which decreases with the temperature increase, after which it tends gradually to the equilibrium value. This trend resulted in agreement with that shown by the lattice damage evolution, as revealed by double crystal x‐ray analysis of the rocking curves of the implanted samples. The SIMS profiles indicated that only a fraction of the dopant which is located at the residual implantation damage is responsible for the anomalous diffusion.