Characteristics of high Al content AlxGa1−xN grown by metalorganic chemical vapor deposition

The epitaxial growth of AlxGa1−xN film with high Al content by metalorganic chemical vapor deposition (MOCVD) has been accomplished. The resulting Al content was determined to be 54% by high resolution X-ray diffraction (HRXRD) and Vegard's law. The full width at half maximum (FWHM) of the AlGaN (0002) HRXRD rocking curve was about 597 arcsec. Atomic force microscopy (AFM) image showed a relatively rough surface with grain-like islands, mainly coming from the low surface mobility of adsorbed Al-species. From transmittance measurement, the cut-off wavelength was around 280 nm and Fabry–Perot fringes were clearly visible in the transmission region. Cathodoluminescence (CL) measurement indicated that there existed a uniformity in the growth direction and a non-uniformity in the lateral direction.