Lattice location and damage distribution in MeV as implanted Si(100) crystals

Samples of Si(100) single crystals have been implanted with As+ ions of 1.0 0 MeV to a dose of similar to 5 X 10(14) cm(-2) at room temperature. Transm ission electron microscopy and combined Rutherford backscattering spectrome try and channelling experiments with a 2.10 MeV He+ beam have been performe d on the implanted samples to study the lattice location of As atoms and re sultant defect configuration after implantation and annealing at 850 degree s C for 30 min. Single alignment angular distributions along [100] and [110 ] axes and a (110) plane for He+ scattering from both the As and Si atoms a t the same depth were measured and presented. The experiments were compared with simulated scans, calculated with the use of a Monte Carlo method, for a variety of assumed lattice sites. Although an inspection of channelling profiles indicates that practically all the As are on substitutional positi ons, these need not be true substitutional positions as it includes defect complexes. Analysis of the data for As, by comparing with computer simulati ons, shows that the experimental results are consistent with the simulated ones with a possible configuration: about 83 +/- 4% are on Si sites and 16 +/- 3.5% occupy a site close to Si with an average displacement of about 0. 014nm along the [100] direction. A tentative explanation for these results is presented.