3-dimensional implantation profiles: The spatial distribution of Nd in Si

Transversal components in ion implantation are available theoretically by the "TRIM" code, and experimentally by a modified tomographic reconstruction from 1-dimensional implantation distributions in various directions. Apart from many cases which reconfirm the 3D-TRIM predictions nicely, we found systems with pronounced deviations in 1 or 3 directions, due to either thermal or radiation-enhanced 3D-diffusion. A new code to treat this 3D post-implantational mobility is illustrated for the example "300 keV Nd/sup +/ in Si". Diffusional changes influence the ratio of lateral to transversal stragglings.