Unfaulting of dislocation loops in the GaInNAs alloy: An estimation of the stacking fault energy.

A study by transmission electron microscopy of the influence of the In and N contents in the ranges of 20%–35% and 1.1%–3%, respectively, on the microstructure of Ga1-xInxNyAs1-y quantum wells is presented. Frank dislocation loops characterized as extrinsic have been found in the samples with x>=0.25. In these structures, threading dislocations appear as a consequence of the unfaulting of the loops for y>=0.014. An analysis of the density and size of the dislocation loops has provided an estimation of the critical radius for the unfaulting process. A model for this critical radius of the unfaulting process of extrinsic Frank loops is proposed. From this model and experimental values of critical radius, an estimation of the stacking fault energy of the GaInNAs alloy has been made. We have found a reduction in the stacking fault energy of the GaInNAs alloys when increasing the N content from 1.4% to 2.3% in good agreement with the theoretical estimation of the stacking fault energies of zinc-blende GaN and InN. [ABSTRACT FROM AUTHOR]