It was recalled that it was well known that cross-hatching appeared on the surface of low-misfit strained semiconductor layers which relaxed via the introduction of arrays of a/2<101> misfit dislocations into the interface between the strained layer and the substrate. A study was made here of the detailed structure of these surface striations, and their evolution with thickness, in a series of InxGa1-xAs monolayers on (001) GaAs; where x was close to 0.15. By means of atomic force microscopy, it was found that the striations were really almost triangular ridges with rounded tops, separated by V-shaped grooves. These were not slip traces. The ridges were asymmetrical in distribution, with those parallel to [110] being far higher than those which were parallel to [110]. The spacings and heights of the ridges increased with layer thickness. The structure also became more disordered in the case of thicker layers; with ridges running for shorter distances and having more complex profiles. By using transmission electron microscopy, it was possible to correlate the ridges with dislocations which lay above, and parallel to, the interface and which resulted from the repeated operation of sources.

R.Beanland, M.Aindow, T.B.Joyce, P.Kidd, M.Lourenço, P.J.Goodhew: Journal of Crystal Growth, 1995, 149[1-2], 1-11