Gettering of iron in silicon by boron implantation

In this work we studied, both experimentally and theoretically the iron gettering by boron implantation. Sample material was p-type bulk silicon with resistivity of 21 Ωcm. Samples were iron contaminated and boron was implanted into the wafers using two different implantation doses of 4 × 1015 and 8 × 1015 cm−2. After that various gettering annealings were performed. The results indicate that gettering cannot be explained by electronic interactions between interstitial iron and boron ions alone i.e. segregation gettering to heavily doped implantation region. It was found out that better agreement between experimental and simulation results is achieved if heterogeneous precipitation of iron to ion implantation induced damage is included in the simulations. Finally, the effects of high boron doping and gettering site morphology on iron precipitation are discussed.