On the generation of a cross grid of extended screw-type misfit dislocations on the ZnSxSe1-x/GaAs interface

Abstract

Abstract New sources for heterogeneous nucleation of both (110) and (110) extended screw-type misfit dislocations to relax the lattice shear stress on the ZnS x Se1-x/GaAs interface have been observed for the first time. These are identified as Shockley partial dislocations originating at the area close to the ZnS x Se1-x/GaAs interface. The Shockley partials are formed for the accommodation of the stacking enors produced upon island coalescence. In-situ electron beam-induced heating studies were carried out to observe the dislocation generation mechanism in the films. Our results show that the stress existing in the ZnS x Se1-x films gives rise to bowing of the threading segments of the Shockley partials. The bowing results from the fact that the dislocations are pinned at the fildsubstrate interface and at the film surface. This process involves an increase in the length of the threading segments under the stress σ ∼ 1 × 109 dyne cm−2. With further accommodation of the lattice strain, the line tension o...