Is the Hagen-Strunk multiplication mechanism of misfit dislocations in heteroepitaxial layers probable?

ABSTRACT The Hagen-Strunk multiplication mechanism of misfit dislocations in latticemismatched heteroepitaxial layers is investigated in the realm of the elasticity theory. A necessary condition for the mechanism is proposed by considering the equilibrium of the forces exerted on a dislocation segment resulting from the annihilation of two crossing misfit dislocations. In the light of this condition, the critical layer thicknesses at which the Hagen-Strunk multiplications cease are calculated for the Ge-GaAs and Si1-x Ge x -Si systems. These critical thicknesses are smaller than the Matthews-Blakeslee critical thicknesses, which suggests that multiplications due to the Hagen-Strunk mechanism are not likely to occur in heteroepitaxial layers.