Scanning tunnelling microscopic topographic images were used to obtain the dimensions of strain fields which were detected at the surface of thin InAs molecular beam epitaxial films on GaAs(110) substrates. The displacements of atoms in the film, due to the edge-dislocation strain fields, were obtained by measuring the depth and lateral dimensions of the surface response as a function of the InAs thickness (up to 30 monolayers). Several models which were based upon elasticity theory were used when attempting to reproduce the experimental measurements. It was found that only those models which included a free epitaxial layer surface gave good quantitative agreement, and the experimentally observed decrease in vertical displacement was found to be due mainly to strain-field superposition as a result of the increasing widths of strain fields which originated from adjacent dislocations.

Dislocation displacement field at the surface of InAs thin films grown on GaAs(110) J.G.Belk, D.W.Pashley, B.A.Joyce, T.S.Jones: Physical Review B, 1998, 58[24], 16194-201