EFFECT OF STRESS SIGN AND FILM THICKNESS ON INTERFACE NUCLEATION OF MISFIT DISLOCATIONS IN STRAINED MULTILAYERS

Abstract

The strain relaxation mechanism via the homogeneous nucleation of misfit dislocations from the heterointerface in coherently strained layers has been investigated with transmission electron microscopy. It is identified that the dislocations nucleated from the interface are displayed in the form of 90-degrees partial, 30-degrees partial, and 60-degrees perfect dislocations, depending on stress sign and thickness of the strained layer. The tendency is interpreted in terms of the strain relaxation efficiency which is given by the ratio of relieved strain energy to dislocation line energy.