SELF-ORDERING OF QUANTUM-WIRE SUPERLATTICES ON V-GROOVED SUBSTRATES

A mechanism of self-ordering of quantum-wire superlattices via growth on nonplanar substrates is described. Alternate deposition of thin lay ers characterized by a longer and a shorter diffusion length of adatom s on a self-limiting V groove yields an exact compensation of the incr ease and decrease in the surface curvature. As a result, a self-limiti ng surface profile develops, which gives rise to a vertically stacked superlattice (SL) of crescent-shaped quantum wires (QWR's). The struct ure of such SL's is accurately modeled using the self-limiting growth characteristics of thick layers of the barrier and well materials. A s ystematic difference, found between the average composition of these Q WR SL's and the corresponding alloys, is interpreted in terms of the r ole of the entropy of mixing in the self-limiting growth process. [S01 63-1829(98)51916-9].