Strain relaxation in heteroepitaxial films by misfit twinning: II. Equilibrium morphology

摘要

The equilibrium morphology of misfit twins in an epilayer with different elastic constants from its substrate is systematically investigated by energy minimization based on the dislocation mechanism of twinning. Explicit formulas for period arrays of misfit twins with the same orientation and with alternating orientations are derived by superposition of the solutions reported in Part I of this series. The equilibrium morphology for a periodic array of misfit twins is characterized by the twin width and the twin mean spacing. The effects of elastic mismatches between the epilayer and the substrate on the equilibrium morphology of twins are also studied comprehensively. The theoretical predictions agree with experimental observations. (c) 2007 American Institute of Physics.