Comparative Spectroscopic Study of Aluminum Nitride Grown by MOCVD in H2 and N2 Reaction Environment

We report a comparative spectroscopic study on the thin films of epitaxial aluminum nitride (AlN) basal plane sapphire (Al2O3) substrates grown in hydrogen (H2) and nitrogen (N2) gas reaction environments. AlN similar thicknesses (~3.0 µm) were by metal-organic chemical vapor deposition (MOCVD) for comparison. The impact environment epilayers was characterized using high-resolution X-ray diffraction (HR-XRD), photoelectron spectroscopy (XPS), Raman scattering (RS), secondary ion mass (SIMS), cathodoluminescence (CL), atomic force microscopy (AFM), scanning electron (SEM). showed that layers N2 have 50% less stress (~0.5 GPa) total dislocation densities (~109/cm2) as compared to H2 environment. On other hand, about 33% lesser carbon 41% oxygen impurities than growth possible mechanisms influenced structural quality impurity incorporation two different environments grow MOCVD system discussed.