InGaN and quasi-InGaN alloy were grown on sapphire (0 0 0 1) substrates by using conventional and ((GaN)(m)/(InN)(n))(s) multilayer methods, respectively. For an InGaN alloy grown by using the conventional method, X-ray diffraction (XRD) showed phase separation of InN for InGaN epilayer of 0.4 mu m thickness having In composition of about 47% and the presence of In droplets was confirmed by scanning electron microscope (SEM). For a quasi-InGaN alloy grown by using ((GaN)(20)/(InN)(20))(15) multilayer structure, XRD showed only two diffraction peaks: One at 34.55 degrees corresponds to GaN buffer layer and the other at 32.95 degrees to a quasi-InGaN with a ((GaN)(20)/(InN)(20))(15) multilayer structure. The diffraction angle from the multilayer structure corresponds to that of an InGaN layer with an In composition of 50%. The surface morphology of this sample was Aat with no In droplets.