Patterned quantum-well structures were implanted with 50keV Ar ions in order to investigate lateral broadening of the implantation-induced defect profile. In order to study the effect of ion channelling upon the lateral spread of the damage distribution, implantation was carried out along channelling axes or along random directions. The degradation of the photoluminescence emission intensity of laterally damaged quantum-well layers was measured as a function of the implantation mask width. The results were modelled by using a simple diffusion calculation which took account of the diffusivity of electron-hole pairs beneath the implantation mask. This model permitted the evaluation of an effective lateral straggling length for channelling, as well as for random implantation. Upon comparison with randomly implanted samples, a clearly reduced lateral spread of the damage profile could be discerned for implantation along the [100] or [110] axes.

A.Kieslich, H.Doleschel, F.Kieseling, J.P.Reithmaier, A.Forchel: Applied Physics Letters, 1996, 68[1], 102-4