Dynamic simulation of damage accumulation during implantation of BF 2+ molecular ions into crystalline silicon

Abstract

The binary collision code Crystal-TRIM is extended in order to include the simulation of BF 2 + molecular ion implantation into (100)-Si. The damage accumulation during ion bombardment is described by assuming statistical creation of local amorphous regions. The program is applied to 35 and 65 keV BF 2 + implantations into channeling and “random” directions, at different doses. Damage accumulation leads to enhanced dechanneling and, therefore, to a strong dependence of the shape of the boron and fluorine depth distributions on the implanted dose. The depth profiles calculated by Crystal-TRIM show a good agreement with experimental data. The dependence of boron and fluorine range distributions on the implanted dose and the direction of ion incidence is described very well by the simulations.