A new technique - vertical micro-channel epitaxy - was described. By using this, a reduction in both the dislocation density and the residual stresses generated in highly mismatched hetero-epitaxial systems (such as GaAs on Si) could be achieved by using molecular beam epitaxy. A narrow window in SiO2 was used to grow GaAs selectively so as to obtain a vertical structure via vertical micro-channel epitaxy. By using optimum growth conditions, vertical micro-channel epitaxial GaAs layers on Si(001) substrates with an aspect ratio of about 2 were grown. A high aspect ratio was beneficial for a reduction in both dislocations and residual stresses. From observations of etch-pit density, it was deduced that a large number of dislocations exited from the side surfaces of the layer. A photoluminescence study indicated that vertical micro-channel epitaxy was also useful for releasing residual stresses in the hetero-epitaxial layer.

A New Way to Achieve Dislocation-Free Heteroepitaxial Growth by Molecular Beam Epitaxy - Vertical Microchannel Epitaxy. Y.Matsunaga, S.Naritsuka, T.Nishinaga: Journal of Crystal Growth, 2002, 237-239, 1460-5. See also: Microchannel Epitaxy - an Overview. T.Nishinaga: Journal of Crystal Growth, 2002, 237-239, 1410-7