Dislocation gliding and cross-hatch morphology formation in AIII-BV epitaxial heterostructures

作者：Kovalskiy V A^*; Vergeles P S; Eremenko V G; Fokin D A; Dorokhin M V; Danilov Yu A; Zvonkov B N

来源：Applied Physics Letters, 2014, 105(23): 231608.

DOI：10.1063/1.4904343

An approach for understanding the origin of cross-hatch pattern (CHP) on the surface of lattice mismatched GaMnAs/InGaAs samples grown on GaAs (001) substrates is developed. It is argued that the motion of threading dislocations in the {111} slip planes during the relaxation of InGaAs buffer layer is more complicated process and its features are similar to the ones of dislocation half-loops gliding in plastically deformed crystals. The heterostructures were characterized by atomic force microscopy and electron beam induced current (EBIC). Detailed EBIC experiments revealed contrast features, which cannot be accounted for by the electrical activity of misfit dislocations at the buffer/substrate interface. We attribute these features to specific extended defects (EDs) generated by moving threading dislocations in the partially relaxed InGaAs layers. We believe that the core topology, surface reconstruction, and elastic strains from these EDs accommodated in slip planes play an important role in the CHP formation. The study of such electrically active EDs will allow further understanding of degradation and changes in characteristics of quantum devices based on strained heterostructures.

• 出版日期2014-12-8