Investigation of the relationship between reflectance difference spectroscopy and surface structure using grazing incidence X-ray scattering

In this work, in-situ grazing incidence X-ray scattering is used to correlate surface structures observed during organometallic vapor phase growth of GaAs with in-situ optical measurements using reflectance difference spectroscopy (RDS). Our observations of several reconstructions confirm that RDS signals vary among the different surfaces present under vapor phase epitaxy conditions, as also occurs under ultra-high vacuum growth conditions. In addition, the simultaneous observation of intensity oscillations in the X-ray scattering signal and the reflectance difference signal indicates that both of these techniques can be used to monitor layer-by-layer growth processes under some conditions.