Blocking of threading dislocations by Hg1−xCdxTe expitaxial layers

Abstract
The process by which threading dislocations present in the substrate are bent into the interface plane during epitaxial layer growth and thus are blocked from propagating into the epitaxial layer has been observed in growth of the II‐VI ternary alloy Hg1−xCdxTe on CdTe and Cd1−zZnzTe substrates. Stereo‐pair transmission electron micrographs were analyzed which clearly revealed the interfacial dislocations to be in a planar network, as has been previously reported for III‐V epitaxial systems in which the blocking mechanism has been identified by other investigators. Additional evidence of the blocking phenomenon has been provided by chemical dislocation‐revealing etching, which verified that the substrate dislocations were not present in the layer.