The strain models of misfit dislocations at cubic semiconductors hetero-interfaces

Abstract

The misfit dislocations at cubic semiconductors hetero-interfaces were quantitatively investigated by high angle dark field scanning transmission electron microscopy in combination with geometric phase analysis and dislocation density tensor analysis. A detailed comparison of the extracted information with the available dislocation models (Peierls-Nabarro and Foreman model) in bulk materials shows that these models can be adapted to the misfit dislocations at lattice mismatched interface. A typical illustration is made for GaSb/GaAs, where it is shown that the strain fields of the 60° dislocation follows the Foreman model (a = 1.8), in case of the Lomer and 60° dislocation pair, the Foreman (a = 2.5) and Peierls-Nabarro model apply for εxx and εyy, respectively.