Silicon nitride thin films have been deposited via distributed electron cyclotron resonance plasma-enhanced chemical vapor deposition, without intentional substrate heating, using SiH4 and N2 gas mixtures. The effects of N2/SiH4 gas flow (1.5–19) and microwave power (800–1500 W) on deposition rate, refractive index, composition, chemical bonds, and etch rate were studied by ellipsometry, MeV ion beam analysis techniques, and Fourier transform infrared spectroscopy. All parameters examined indicate that a highly diluted SiH4 gas phase and a microwave power of 1500 W help to prepare quasistoichiometric films with a high density (2.9 g/cm3) and a refractive index of 1.98. The effects of film density and film stoichiometry (N/Si) on refractive index are discussed through the Lorentz–Lorenz relation. The first electric results show that, under the optimized deposition parameters, a critical field of 2.3 MV/cm and an interface state density of 5×1010 eV−1 cm−2 can be achieved.

International audienceDielectric behavior of films, fabricated by microwave electron cyclotron resonance discharge, has been studied as a function of film thickness on the basis of the current-voltage and the capacitance-voltage characteristics. In the thickness range the resistivity and the critical field for were found not to be sensitive to the film thickness (d) and which was opposite to strong dependence of the dynamic dielectric constant on thickness. To explain the behavior as a function of d, a model based on trapped space charge effects is proposed. The dominant mode of electronic conduction, determined from curves and Arrhenius plots of leakage current, appears to be Poole-Frenkel emission only for thicker films Finally, the spatial profile of fixed charges reveals that interface has a much greater concentration of defects than the bulk film

Amorphous carbon-based coatings deposited on copper substrates by magnetron sputtering at different target-to-substrate distances were investigated. Films deposited at short distances as 2 cm presented the best results in terms of morphology, density, and resistivity. Ultraviolet near-infrared range spectrometry measurements determined total reflectance and ellipsometry, extinction coefficient, refraction index, and pseudo bandgap. Amorphous carbon films of 150 nm deposited at 2 cm reduced the total reflectance by up to 60 ± 5% in the near-infra-red range when compared to pure copper films. The addition of Fe*boosts the absorption of the coating reducing the total reflectance by up to 70 ± 5% in near-infrared. (Fe*: deposited from stainless-steel target used in direct-current magnetron sputtering). Also, it reduces the electrical resistivity by a factor of 100 compared to that of pure amorphous carbon films. The reduction in total reflectance induced by the presence of the amorphous carbon-based films on copper depends, as expected, on light penetration depth and the absorption coefficient.