GaAs (001) surface structural transitions induced by Ga deposition were studied through the correlation between reflection high-energy electron diffraction specular beam intensity variations and observed reconstruction changes. Surface stoichiometry variations associated with the onset of each surface reconstruction were measured. From the best defined 2 x 4 reconstruction to the onset of the 3 x 1 and 4 x 6 reconstructions, As surface coverage variations of 0.31 and 0.53ML were found, respectively. Results were also obtained for other surface reconstructions: c(4 x 4), 4 x 8 (reported for the first time in molecular beam epitaxy) and 4 x 2. In addition, the study clearly showed that each surface reconstruction exists over a rather wide surface stoichiometry range.

Surface Stoichiometry Variation Associated with GaAs (001) Reconstruction Transitions. C.Deparis, J.Massies: Journal of Crystal Growth, 1991, 108[1-2], 157-72