OBSERVATION OF STRAIN RELAXATION PHENOMENA IN BURIED AND NONBURIED III-V SURFACE GRATINGS THROUGH HIGH-RESOLUTION X-RAY-DIFFRACTION

We present high-resolution x-ray diffraction studies describing the ev olution of the strain relaxation phenomena in a strained InGaAsP surfa ce grating resulting from burying in InP. We have compared reciprocal space maps of symmetrical and asymmetrical reflections from free-strai n gratings, strained surface gratings, and strained buried gratings. A fter burying, modifications in the coherently and diffusely scattered intensity have been observed indicating the counteraction of the embed ding material to the laterally nonuniform strain relaxation, which occ urs in free-surface (nonburied) strained grating. (C) 1997 American In stitute of Physics.