In order to predict the type and number of defects which were created by keV ions during implantation, computer simulations which were based upon the binary collision approximation were combined with classical molecular dynamics calculations. Time-ordered binary collision approximation simulations were applied to ballistic processes with characteristic energies above several tens of eV. Athermal, rapid thermal and thermally activated processes with lower characteristic energies were treated by molecular dynamics simulation. This yielded the as-implanted defect state which was formed several tens of ps after ion impact. The molecular dynamics calculations were performed using cells which were much smaller than the entire volume of the collision cascade of an incident ion, but were much larger than the distance between nearest-neighbour atoms in the lattice. The as-implanted damage which was produced by a single ion in a given cell was found to be completely determined by the nuclear energy deposited into the cell by the ion. Therefore, molecular dynamics calculations had to be performed in only one cell for various values of nuclear energy deposition, and statistical considerations based upon binary collision approximation simulations could be used to obtain the depth profile and the total number of different defect species (vacancies, interstitials, disordered atoms, etc.) which were created, on average, per incident ion. The present simulation method was used to investigate the damage morphology which was produced by 15keV B+, 30keV P+ and 15keV As+ implants.

Prediction of the Morphology of As-Implanted Damage in Silicon using a Novel Combination of BCA and MD Simulations. M.Posselt: Materials Science in Semiconductor Processing, 2000, 3[4], 317-23