High-resolution triple-axis x-ray diffractometry has been used to exam
ine the structural properties of a delta-doped superlattice of sixty p
eriods, each consisting of half a monolayer of Si and 500 angstrom of
GaAs, grown by molecular beam epitaxy (MBE) at 400-degrees-C under an
arsenic flux. The measurements indicated that the superlattice was of
high structural quality. Using dynamical simulation, it was demonstrat
ed that the period variation was equal to 3%, while the silicon spread
ing was no greater than 2 monolayers. It was possible to extract this
information because of the high-resolution diffractometer which produc
ed the theoretical line shape and wide dynamic range. Using a simple m
odel, it was deduced that virtually all Si atoms were located on Ga la
ttice sites.