Misfit dislocations in heteroepitaxial Si on sapphire

Abstract

Edge‐type misfit dislocations have been observed near the original growth interface of heteroepitaxial (100) Si/(011̄2) sapphire. They were seen in Si islands existing prior to complete substrate coverage. The Si was deposited from the vapor phase at 1000 °C. The dislocations lie parallel to the [022] and [022̄] directions. The edge character of the dislocations was established by diffraction contrast experiments, and also from the fact that their spacing is twice that of the corresponding moiré fringes. Their misfit‐relieving nature is implied from the fact that their spacing (36.9±6.0 Å) compares favorably with that calculated for almost total misfit relief (37 Å).