Oblique stacking of three-dimensional dome islands in Ge/Si multilayers

The organization of Ge "dome" islands in Ge/Si multilayers has been investi gated by cross-sectional transmission electron microscopy. Ge domes are fou nd to spontaneously arrange in oblique stacks, replicating at a well-define d angle from one bilayer to the next. The formation of oblique island stack s is governed by a complex interplay of surface strain, generated by the al ready buried islands, and surface curvature, caused by the inherent tendenc y of large domes to carve out material from the surrounding planar substrat e. (C) 2001 American Institute of Physics.