Surface atomic configurations due to dislocation activity in InAs/GaAs(110) heteroepitaxy

The surface of a compressively strained InAs epilayer grown on a GaAs(110) substrate has been resolved at the atomic level by scanning tunneling microscopy. The growth of the InAs film ( > 5 ML ) involves a class of dislocations which are nucleated at the surface and subsequently channeled down to relieve the strain at the buried interface with the GaAs substrate. The effects of the disruption to the atomic geometry in the InAs surface layer due to this dislocation motion, and the accommodation of these imperfections by continuing epitaxy, are presented.