Stress relaxation by generation of L-shape misfit dislocations in (001) heterostructures with diamond and sphalerite lattices

The problem of generation of L-shape misfit dislocations (MDs) is investiga ted for (001) heterosystems with diamond and sphalerite crystal structures. These 60 degrees MDs can be formed by modified Frank-Read dislocation sour ces as well as by Hagen-Strunk ones. The analysis shows that perpendicular dislocation lines included in L-shape MDs have different types of screw dis location components (namely, left-screw and right-screw ones). As a result, the stress-releasing process tends to slow preventing further generation o f L-shape dislocations and annihilation of threading dislocations (TDs). To minimize density of TDs and to form equilibrium plane MD networks at the f inal stage of stresses relaxation process, it is necessary to generate mutu ally perpendicular MD arrays with the same types of screw dislocation compo nents. (C) 2000 Elsevier Science B.V. All rights reserved.