Evolution and Intersection of Extended Defects and Stacking Faults in 3C-SiC Layers on Si (001) Substrates by Molecular Dynamics Simulations: The Forest Dislocation Case

The crossing of stacking faults (SFs) (namely dislocation forests) in 3C-SiC is experimentally probed to cause detrimental effects on the electronic properties of the layer. By means of classical molecular dynamics simulations, for the first time the evolution of two crossing partial dislocation loops is shown, revealing the mechanism that leads to the formation of a complex defect at their intersection. The obtained atomistic structure is then further refined by ab initio calculations, revealing that this defect does not cause defect states within the gap of the pristine material. The case of the intersection of two double-dislocation loops, that is, involving double SFs, in the hypothesis that the evolution follows the same mechanism found for single-dislocation loops is also investigated. Contrary to the single-plane intersection, the simulations reveal that the junction formed by double-dislocation loops does cause intragap states, thus suggesting detrimental effects on the electronic properties of the 3C-SiC layers.