Reduction of threading dislocation density in SiGe epilayer on Si (0 0 1) by lateral growth liquid-phase epitaxy

Abstract

Si0.973Ge0.027 epilayers were grown on a Si (0 0 1) substrate by a lateral liquid-phase epitaxy (LLPE) technique. The lateral growth mechanism favoured the glide of misfit dislocations and inhibited the nucleation of new dislocations by maintaining the thickness less than the critical thicknesses for dislocation nucleation and greater than the critical thickness for glide. This promoted the formation of an array of long misfit dislocations parallel to the [1 1 0] growth direction and reduced the threading dislocation density to 103 cm−2, two orders of magnitude lower than the seed area with an isotropic misfit dislocation network.