Characterization of LEC GaAs by electron beam induced current analysis

Some considerations are presented to show that the currently used models of electron beam induced current (EBIC) contrast at dislocations are not sufficient to analyse fully complex defect structures such as very large impurity clouds in LEC GaAs. These large impurity clouds were therefore investigated by the energy dependent EBIC method. In this way the involvement of the shallow dopant impurities can be established. It is stressed that, because of the pronounced short range inhomogeneous distribution of impurities and dislocations in bulk LEC GaAs crystals, the energy dependent EBIC method in planar geometry is a very efficient method for investigating such crystals since it has a very high spatial resolution and allows determination of the shallow dopant density.