Tuneable Properties of Aluminium Oxynitride Thin Films
- Pp. 195-229 (35)Joel Borges, Nuno P. Barradas, Eduardo Alves, Nicolas Martin, Marie-France Beaufort, Sophie Camelio, Dominique Eyidi, Thierry Girardeau, Fabien Paumier, Jean-Paul Rivière, Filipe Vaz and Luis Marques
In this subchapter is discussed some characteristics and properties of AlO<sub>x</sub>N<sub>y</sub> thin films produced by reactive DC magnetron sputtering. The films were deposited using Ar as working gas and a reactive gas mixture of N<sub>2</sub>+O<sub>2</sub> (17:3). The reactive gas flow was varied in order to produce a wide range of chemical compositions. Sub-stoichiometric AlO<sub>x</sub>N<sub>y</sub> films, with C<sub>O+N</sub>/C<sub>Al</sub> atomic ratios up to 0.85 were produced, with Al-type crystalline structure. Transmission electron microscopy (TEM) analysis and X-ray photoelectron spectroscopy (XPS) spectra suggests that the films are a percolating network, composed by aluminium nanocrystals with different shapes and sizes embedded in an oxide/nitride matrix. The particular composition, structure and morphology of the films results in very different electrical properties, which can be explained using a tunnel barrier conduction mechanism for the electric charge transport, as well as distinct optical responses, such as an unusual large broadband absorption for some films.