Surface reconstructions of InGaAs alloys

The atomic surface structures of InGaAs lattice-matched and 1.9% compressively strained alloys were examined using in situ scanning tunneling microscopy. The surface of the lattice-matched films is comprised of an anion-rich but mixed-termination (4x3) or (6x4) reconstruction. The strained alloys exhibit regions of the same reconstructions, in addition to pockets of alpha2(2x4) in the case of the In0.27Ga0.73As/GaAs films, and beta2(2x4) in the case of the In0.81Ga0.19As/InP. Annealing experiments show that the coverage of the alpha2(2 x 4) and beta2(2 x 4) regions decreases with increasing annealing time. Therefore, it is postulated that the composition of these (2 x 4) reconstructions is enriched in In compared to the (4 x 3)/(6 x 4). (C) 2004 Published by Elsevier B.V.