By the simplified molecular method just one (significant) atom species of the molecule is consider rigorously, which means that just the implanted distribution of this species is calculated. As well in case of BF as of BH ion implantation boron is the significant species. All other atom species in the molecule are considered as being not relevant for the simulation. Just their influence on the trajectories of the significant species by producing additional damage in a crystalline target is taken into account.
When simulating the implantation of a molecular ion with the simplified molecular method a simulation of a single atomic ion is performed whose implantation energy is equivalent to the reduced energy calculated by (4.6).
The simplified method is only applied in combination
with the modified Kinchin-Pease damage model. The higher damage generation rate
of the molecular ion is modeled by modifying the recombination parameters of
the implanted species (Sec. 3.3.5). The higher dose rate according to
the larger number of similar atoms in the molecule is treated by multiplying all
concentrations with the number of atoms of this species in the molecule. For
instance in case of BH a factor of 10 is
used. Tab. 4.2 summarizes the modified
recombination parameters for the supported molecular ions.
A fundamental requirement to apply the simplified molecular method is that the distributions of all implanted atom species have a similar shape, because it is assumed that the damage distribution generated by the neglected atom species can be approximated by multiplying the damage profile generated by the significant atom species.
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