Abstract:The effects of reactant-gas velocity on the growth of InN on GaN/sapphire substrate by organometallic vapor-phase epitaxy (OMVPE) were studied. With a high-speed reactant gas, the thickness of the stagnant layer is reduced so that the reactant species can reach the surface effectively. A layerlike growth of InN was achieved, resulting in a marked improvement of the film quality. In addition, significant enhancement of the growth rate up to 2 µm/h was obtained. The full-width at half maximum (FWHM) of the X-ray rocking curve (XRC) decreased with increasing gas velocity. A 476 arcsec width of XRC was reproducibly achieved, indicating high-quality InN epitaxial films. A Hall mobility of 250 cm2/V-s with a carrier concentration of 1×1019 cm-3 at room temperature was obtained on a 0.5-µm-thick InN film.