Mathematical simulation of technologies of ion implantation into crystalline materials and nanostructures (see Fig.1) is considered today as a primary instrument for optimization of technological processes used to develop materials with desired properties for microelectronics and the advanced radiation nanotechnologies.
Fig. 1 – Nanotubes
To predict the profiles of ion implantation into single crystals the researchers of SPE RESST have formulated the stochastic theory on the kinetics of low-energy ion axial channeling with taking into account the total energy losses during the ion motion in the channel [7,22]. Besides, the profiles were independently simulated by the methods of binary collisions. The molecular dynamics, using the developed original program MICKSER, demonstrates a good quantitative agreement of theoretical calculations and simulation results with reliable experimental data. It is shown, that the directional dependences of the ion implantation profile shape are in close agreement with the theoretical criteria of channeling stability. In the case of ion incidence far from the lattice channel directions, the presence of long-range tails in the implantation profiles is determined by the effect of volume capture of ions into the axial channels.
Fig.2. Results of theoretical calculations and computer simulations on the profiles of different-energy boron ion implantation along the axial channel <100> of the silicon crystal in comparison with experimental data
Along with the implantation into crystals currently of a great interest is the accelerated ion implantation into nanostructure materials, in particular, with a view to use nanostructures as hydrogen media-accumulators for the needs of alternative hydrogen energy [2,3]. By the program MICKSER using the computer simulation methods, for the first time, the profiles of medium-energy ion implantation into the superlattices of single-layer non-chiral carbon nanotubes under channeling conditions were constructed (Fig.3).
Fig. 3 – Results obtained by the computer simulation methods
The multipeak structure of implantation profiles was found and explained, the main mechanisms of profile formation were revealed. The computer simulation methods were also applied to study the possible alternatives for the accelerated charged particle beams handling with the use of different mechanisms of their reflection from the surface [23, 24] and macrochanneling in collimators and nanocapillars [25].