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Thin films of TiN x O y were deposited by d.c. magnetron sputtering on glass substrates using an (Ar + ,N 2 ) plasma and Ti target. The N 2 partial pressure was changed from 2.3 × 10 −4 mbar to 4.6 × 10 −3 mbar in order to obtain films with increasing nitrogen contents. X-ray photoelectron spectroscopy was used to determine the as-deposited composition. The presence of oxygen, which is probably due to contamination from the residual atmosphere in the vacuum chamber, is always detected, both in the surface layers and in the bulk of the films, confirming the formation of TiN x O y . When the nitrogen partial pressure was increased, a maximum for the nitrogen content in the films was reached, corresponding to a TiN 0.8 O 0.4 film composition. The nitrogen content of the films did not increase further for higher N 2 partial pressures. X-ray diffraction showed that each deposited layer had a rock salt structure, isomorphic to that for TiN, in which some nitrogen atoms would seem to be substituted by oxygen atoms in the anionic sub-lattice. Moreover, this crystalline TiN x O y phase is super-stoichiometric with this deposition method. To the best of our knowledge such results have already been observed on TiN films but it is the first time that they have been presented for TiN x O y thin layers.

Direct current reactive magnetron sputtering was implemented to successfully deposit dark Ti(C,O,N) thin films on silicon substrates. A titanium target was sputtered while a mixture

Optical properties of novel micrometer-size Ga and GaN three-dimensional structures obtained by the metal-organic chemical vapour deposition (MOCVD) technique are presented in this letter. These structures are obtained as metallic three dimensions (3D) micrometer-size objects on an appropriate substrate by metalorganic (TMGa) pyrolisis and then GaN transformed on annealing under NH3 atmosphere at 650–750°C. These 3D GaN structures are analysed by optical means, using two-photon excitation (800 nm) and by UV Hg lamp fluorescent spectroscopy techniques, adapted to two-optical-microscopes apparatus. Very intense and blue/yellow light emission is observed from these 3D structures under 800 nm two-photon laser excitation and under UV Hg lamp excitation.

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Titanium oxynitride (TiN x O y ) thin films were deposited by low-pressure metal±organic CVD (LP-MOCVD) on (100) silicon, sapphire, and polycrystalline alumina substrates. Titanium isopropoxide (TIP) and ammonia were used as precursors. The influence of the growth temperature, ranking from 450 C to 750 C, was investigated by scanning electron microscopy (SEM), and electrical DC measurements. Rutherford back-scattering (RBS) measurements were used to determine the N/O ratio in the films. The surface observations of the deposited films showed two morphological transitions. The resistivity decreased with the growth temperature, while the nitrogen content increased. Moreover, for the highest deposition temperatures, the temperature dependence of the resistivity revealed a transition from a semiconducting to a metallic behavior. Finally, these electrical properties were correlated with the two morphological transitions.