Changes generated by the post-annealing treatment of a nano-indentation structure on GaAs(001) were studied. The nano-indentations were performed by using loads of between 0.5 and 10mN at room temperature and were then annealed (500C, 1h). Transmission electron microscopy was used to observe the nano-indentation structures before and after annealing. The size of the dense plastic zone generated around the indentation site was decreased by about 20% by annealing, and rosette arms propagated along the <110> directions parallel to the indented surface. The lengths of the rosette arms were multiplied by a factor of 3 during annealing, and the arrangement and structure of the dislocations changed markedly. Hair-pin dislocations which began from the side of the indentations before annealing transformed into alignments of half-loop dislocations. No partial dislocations were observed after annealing, whereas some could be detected before annealing.

Effects of Annealing on Structure of GaAs(001) Nano-Indentations. E.Le Bourhis, G.Patriarche: Philosophical Magazine Letters, 2003, 83[3], 149-58