Investigation of Random and Channeling Ar+Implantation-Induced Damage in Al(In)GaAs/GaAs Quantum Wells

Abstract
Ar+ ion implantation at energies up to 170 keV in GaAs/GaAlAs and InGaAs/GaAs quantum wells is used in order to study the profile of the implantation induced damage as a function of the implantation parameters like the ion energy, the ion dose and the angle of incidence. The photoluminescence (PL) emission intensity of single quantum wells (SQW) at different positions in the layer structure is used as a local probe for the study of the damage. The influence of ion channeling on the damage is investigated by varying the angle of incidence of the ion beam systematically through the major crystallographic axes of the sample. In the experiment we observe even for random implantation an unexpectically wide extension of the defect profiles, which can be described by a characteristic decay length due to a long ranging exponential tail of the damage profile. Compared to the results of random incidence ion implantation along the (100), (110), (111), and (211) axis leads to effective extensions of the damage up to a factor of about four due to ion channeling.