NUMERICAL-CALCULATION OF EQUILIBRIUM CRITICAL THICKNESS IN STRAINED-LAYER EPITAXY

We calculate by numerical integration the energy of a strained layer in an infinite isotropic continuous elastic medium with and without a misfit dislocation dipole of pure edge character. The equilibrium critical thickness is the thickness at which these energies are the same. Solving for a range of values of misfit strain, we compare the results with some versions of the existing approximate models, and we are thereby able to indicate the best analytic expressions to use to predict equilibrium critical thickness.