Defect generation in high In and N content GalnNAs quantum wells: unfaulting of Frank dislocation loops

摘要

We have studied by transmission electron microscopy the defect generation in GalnNAs quantum wells when increasing the In and N contents in the range 20-35% and 1.3-2.3%, respectively. This analysis has shown the appearance of extrinsic Frank dislocation loops for In > 25%, and of threading dislocations for In=35% and N > 1.4%. It is proposed that the threading dislocations are formed from the unfaulting of the Frank loops. A new theoretical model for the process of unfaulting of extrinsic loops is proposed, which has allowed us to calculate the stacking fault energy in the GalnNAs alloy.