Selective area growth of GaN on GaAs(0 0 1) substrates by metalorganic vapor-phase epitaxy

Abstract

Selective area growth (SAG) of GaN on SiO 2 stripe-patterned GaN/GaAs(0 0 1) substrates was carried out by metalorganic vapor-phase epitaxy. The SAG samples were investigated by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). SEM observations showed that the morphology of SAG GaN is strongly dependent on the window stripe orientation and slightly affected by the orientation relationship between the window stripes and the gas flow. The (1 1 1)B sidewalls formed on the SAG GaN stripes are found to be stable. XRD measurements indicated the full-widths at half-maximum (FWHMs) of cubic GaN (0 0 2) rocking curves are reduced after SAG. The measured FWHMs with ω-axis parallel to [1 1 0] are always larger than the FWHM values obtained with ω-axis parallel to [1 1 0], regardless of the orientation relationship between the ω-axis and the GaN stripes.