Interactions of impurities with dislocations: Mechanical effects

Impurity effects on the dislocation behavior and mechanical strength of elemental and III-V compound semiconductor crystals, originating in the interaction between dislocations and impurities, are reviewed on the current understanding. A variety of impurities in semiconductor crystals affect the dynamic activities of individual dislocations and, in turn, the mechanical strength of the crystal through two kinds of microscopic mechanisms; one is modification of the dislocation mobility in glide motion and the other is the immobilization of dislocations. It is shown how such impurity effects on the behavior of individual dislocations are reflected on the macroscopic mechanical properties of semiconductor crystals.