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

Good-optical-quality, thick InxGa1−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.