Thickness variations in quantum wells which had been grown onto patterned substrates, via molecular beam epitaxy, were analyzed by using spatially and spectrally resolved low-temperature cathodoluminescence methods. In the case of lower and upper (100) facets which were joined by an angled (311)A facet, relative increases in the quantum-well thickness, of up to about 6% and 20% respectively, were observed in the vicinity of the facet intersection. The Ga adatom migration length obeyed an exponential behavior and ranged from 0.001 to 0.002mm on both the lower and upper (100) facets. It was independent of the quantum-well thickness. The present migration length was some orders of magnitude greater than that which had previously been reported for Ga adatoms during molecular beam epitaxial growth.

S.Nilsson, E.Van Gieson, D.J.Arent, H.P.Meier, W.Walter, T.Forster: Applied Physics Letters, 1989, 55[10], 972-4