ANNEALING EFFECT ON VIBRATION MODES OF ALUMINUM NITRIDE THIN FILMS

Abstract

Reactive magnetron sputtering was used to prepare aluminum nitride (AlN) films at an intermediate substrate temperature of 450 ºC. In order to analyze the microstructure and vibrational phonon modes of AlxNy and AlmOn clusters, the sample was subjected to thermal annealing in a controlled nitrogen atmosphere at temperatures of 550 ºC and 650 ºC, for 20 minutes. The morphological surface was studied by scanning electron microscopy (SEM), and allows us to determine the size, geometry and the facets formation of AlN crystals. The change of microstructure from wurtzite-AlN as-prepared cubic-AlN annealing samples is discussed. From Fourier transform infrared spectroscopy (FTIR) measurements in the range of 650 to 2000 cm-1, the phonon frequencies of AlxNy and AlmOn clusters were obtained. The experimental frequencies were compared to theoretical calculations by using density Functional theory (DFT).

Keywords

• Aluminum nitride
• Magnetron sputtering
• FT-IR.