The electrical properties of lattice mismatch-induced defects in heterojunctions were studied by using electron beam-induced current methods, scanning electron microscopy and deep-level transient spectroscopy. The latter measurements, carried out using p-n junctions formed at the interfaces, revealed one electron trap and two hole traps which were introduced by the lattice mismatch. The electron trap, at about Ec-0.68eV, was attributed to electron states that were associated with threading dislocations in the ternary compound. By comparing the concentration of this trap, as revealed by deep-level transient spectroscopy, with electron beam-induced current results on the diffusion length for heterojunctions having various lattice mismatches, it was deduced that the minority-carrier lifetime was controlled by dislocations in the epilayer region close to the interface. Two new hole traps were attributed to defects which were associated with the lattice-mismatched interfaces of the heterostructures.

Deep-Level Defects at Lattice-Mismatched Interfaces in GaAs-Based Heterojunctions. T.Wosiński, O.Yastrubchak, A.Makosa, T.Figielski: Journal of Physics - Condensed Matter, 2000, 12[49], 10153-60