Transmission electron diffraction was used to observe extra diffraction spots in the transmission electron diffraction patterns of molecular beam epitaxial GaAs1−ySby layers with y = 0.25, 0.50 and 0.71 grown at 520C onto (001) GaAs substrates. Half-order diffraction spots in the transmission electron diffraction patterns indicated ordering on the (¯111) and (1¯11) planes of the group-V sub-lattice, and streaks with subsidiary spots indicated a modulation in the [110] direction with a periodicity of ~4d110. Streaks in the [001] direction indicated monolayer disruptions of the {111} ordering and the [110] modulation in the [001] direction. As the composition parameter y was varied, there were progressive changes in the {111} ordering, the [110] modulation, and the [001] disruptions, and these correlated with corresponding changes in the reconstruction of the dangling bonds at the growing layer surface, as determined by reflection high-energy electron diffraction. A model was proposed to explain the observed effects in terms of ordered atomic arrangements of the group-V atoms resulting from the surface reconstruction being incorporated into the bulk epitaxial layers.

Observation of {111} Ordering and [110] Modulation in Molecular Beam Epitaxial GaAs1−ySby Layers - Possible Relationship to Surface Reconstruction Occurring during Layer Growth. I.J.Murgatroyd, A.G.Norman, G.R.Booker: Journal of Applied Physics, 1990, 67[5], 2310