Study of Extended Electrically Active Defects in (Ga,Mn)As/(In,Ga)As Based Heterostructures by Electron Beam Induced Current and Deep Level Transient Spectroscopy Techniques
Electrically active defects in (Ga,Mn)As/(In,Ga)As heterostructures, both in the GaAs and InGaAs epitaxial layers and near the interfaces, are studied by electron beam induced current and deep level transient spectroscopy techniques. On the images obtained by electron beam induced current technique, extended defects are observed not only near the GaAs/InGaAs interface but in the entire InGaAs layer up to its upper edge. Two deep levels (EV +0.50 and +0.65 eV), which could be related to extended defects, are revealed in the lower part of the bandgap in the structures under study. Possible relation between the deep levels observed in the spectra and the extended recombinationally active defects revealed by electron beam induced current method is discussed.