Growth of optical-quality, uniform In-rich InGaN films using two-heater metal-organic chemical vapor deposition

Good-optical-quality, thick In_xGa_1-xN films with high In content were grown using a homemade two-heater metal-organic chemical vapor deposition system. By varying the growth temperature, it was found that the In composition of the InGaN epilayer varied from 18 to 59% as the substrate temperature decreased from 750 to 625 C. Our results show that the optical properties in terms of the emission peak wavelength and linewidth are uniformly distributed throughout the entire 2 in. wafer for the x=0.40 InGaN sample. The resultant mean peak wavelength and FWHM are 808±6 nm and 229±18 meV, respectively, at 18 K. In addition, for the InGaN film grown at 625 C, a noticeable decrease in the In composition occurred when the ceiling temperature was >800 C, indicative of the occurrence of parasitic reactions in the gas phase.