Analysis of dislocations creating monomolecular growth steps

Abstract

During liquid-phase epitaxial growth of GaAs monomolecular growth steps, created at the growth interface, arrange themselves into regular patterns around well-defined centres. The nature of these centres is investigated by high-voltage electron microscopy. Each centre has been found to correspond to a dislocation. In addition to examples in which dislocations possess non-vanishing Burgers vector components perpendicular to the growth interface (in accordance with Frank's model), others have been found whose Burgers vectors do not have a component normal to the growth interface. The latter examples, denoted “transverse step sources” in this paper, show that even dislocations without a Burgers vector component perpendicular to the growth interface create growth steps. The efficiency of these transverse step sources is similar to that of Frank's screw-dislocation step sources, correspondingly denoted “longitudinal step sources”.