High resolution X-ray diffraction study of InAs layers grown with and without bismuth flow on GaAs substrates by metalorganic vapor phase epitaxy

Abstract

InAs layers were grown with and without bismuth flow by atmospheric pressure metalorganic vapor phase epitaxy on exactly oriented, 2° and 10° misoriented (100) GaAs substrates. Structural analysis was carried out using high resolution X-ray diffraction. Without bismuth flow, only InAs layers grown on 10° misoriented substrates exhibit a mosaic structure. Layers grown on exactly oriented and 2° misoriented substrates show large full widths at half maxima of their diffraction rocking curves. Growing InAs under bismuth flow leads to the reduction of this full width indicating a clear improvement of their structural quality. Particularly for samples grown on 10° misoriented substrates, a complete disappearance of the mosaic structure was obtained. The crystalline quality improvement is attributed to the contribution of Bi nanodots in relieving strain.