In the growth of Si_1−xGe_x films on Si(001), the growth front undergoes a series of elastic stress relief mechanisms. We use these mechanisms in the molecular-beam-epitaxy growth of SiGe/Si superlattices to create relatively periodic surface and interface patterns of small coherent 105-faceted SiGe crystallites. The self-organization of these islands is affected in different ways by tuning substrate miscut, alloy composition, and layer thickness.