Multilayered gratings have been investigated by high-resolution grazin
g incidence diffraction, employing noncoplanar triple crystal diffract
ometry. A theoretical treatment has been developed based on the distor
ted wave Born approximation for multilayer diffraction. Grazing incide
nce diffraction reveals as an optimal complement to symmetrical and as
ymmetrical high-resolution X-ray diffraction. The method allows to mea
sure separately the influences of the lateral strain and the grating s
hape. Depth selective studies have been performed by surface gratings
and buried gratings showing for the first time the evolution of the st
rain relaxation phenomena in strained InGaAsP surface gratings resulti
ng from burying in InP. (C) 1998 Published by Elsevier Science B.V. Al
l rights reserved.