Abstract
The critical epilayer thickness for the formation of misfit dislocations at the interface between an epilayer and a substrate with a finite thickness is derived in the present study. The analysis is based on the energy approach, in which the self-energy of dislocation, the interaction energy between the dislocation and free surfaces, and the lattice mismatch energy of substrate and epilayer are calculated. To satisfy the free surface condition, the methodology of superposition principle and Fourier transformation are used in analyzing the stress field due to the interface dislocation. The critical epilayer thickness is compared with those reported in the literature. © 1999 American Institute of Physics.