PHYSICALLY-BASED MODELING OF 2-DIMENSIONAL AND 3-DIMENSIONAL IMPLANTATION PROFILES - INFLUENCE OF DAMAGE ACCUMULATION

The alteration of the shape of one-dimensional, two-dimensional (2D), and three-dimensional (3D) range distributions with growing dose as we ll as the extension of amorphous zones formed at high doses is studied for 15 keV BF2+ and 30 keV P+ implantations into (100)Si using the dy namic binary collision code Crystal-TRIM. The range and damage profile s are calculated for the area 97.74 (parallel to [010])x97.74 (paralle l to [001]) nm(2) at the target surface irradiated by the ion beam and surrounded by impenetrable masks. The change of the shape of the 2D a nd 3D distributions In the lateral direction is less pronounced than i n the depth direction. At low doses the lateral profile branches are d etermined by rechanneled particles, at high doses the enhanced dechann eling is the reason for the increased lateral straggling. The latter e ffect is responsible for the relatively large lateral extension of the amorphous zone beneath the tasks. The simulated depth profiles of bor on and phosphorus and the predicted thickness of the amorphous layer a re in good agreement with experimental data. (C) 1998 American Vacuum Society.