Shallow boron dopant on silicon: An MD study

Abstract

Low energy boron bombardment of silicon has been simulated at room temperature by molecular dynamics (MD). Tersoff potential T3 was used in the simulation smoothly linked up with the universal potential. The boron–silicon (B–Si) interaction was simulated according to Tersoff potential for SiC but modified to account for the B–Si interaction. The algorithm can distinguish a B from a Si neighbour. Si-c, with (2 × 1) surface reconstruction, was bombarded with boron at 200 and 500 eV. These energies were initially chosen as good representative values of the low energy range. Reliable results require of a reasonable good statistic so that 1000-impact points were chosen uniformly distributed over a representative area of a 2 × 1 surface. The distribution of mean projected range for B is given. All kinds of point defect were looked for in a Si damaged target after bombardment. Energetically stable substitutional and interstitial configurations are presented and the relative appearances of the different types of interstitials, for both Si and B, are given. It is also determined the mean length of the distance to the first neighbours of defects.