Effect of Growth Temperature on Structure Properties of Inn Grown by Pressurized-Reactor Metalorganic Vapor Phase Epitaxy

The effect of the growth temperature on InN films grown at 500-725 degrees C by the pressurized-reactor metal organic vapor phase epitaxy (PR-MOVPE), which is designed to apply high nitrogen pressure to the reactor, has been studied. The growth temperature is found to greatly influence the surface morphology. The columnar islands appear at the growth temperature lower than and equal to 575 degrees C while the coalescence of islands occurs and forms continuous films at the growth temperature higher than 575 degrees C. Step-flow-like morphology is actually observed in the growth temperature range as high as 600-650 degrees C.However, at this high growth temperature range, the diffraction peak of metallic indium appears in XRD spectra. Therefore, it is in a dilemma to enhance the surface migration and prevent the precipitation of metallic indium. Our experimental results indicate that the growth temperature of InN can be increased using the pressurized growth conditions and the epitaxial temperature around 575 degrees C is best to obtain a good crystalline quality InN films without the precipitation of metallic indium at present growth pressure. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim