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Amorphous carbon nitride (a-CN[sub x] ) films were grown on silicon substrates by ArF excimer laser ablation of a graphite target in the presence of nitrogen at various gas pressures. By working at elevated pressures (up to 100 Pa), large amounts of nitrogen can be incorporated into the films (up to 40 at. %, which leads to a strong enhancement of their field emission properties. This behaviour was demonstrated to be mainly related to changes in the surface morphology of the samples, in connection with the development of graphite-like structures. [ABSTRACT FROM AUTHOR]

Amorphous carbon nitride (a-CNx) films were grown on silicon substrates by ArF excimer laser ablation of a graphite target in the presence of nitrogen at various gas pressures. By working at elevated pressures (up to 100 Pa), high amounts of nitrogen can be incorporated into the films (N/C≤0.4) which lead to strong enhancement of their field emission properties. This behaviour was demonstrated to be mainly related to changes in the surface roughness of the samples, in connection with the development of graphite-like structures. [Copyright &y& Elsevier]

Amorphous carbon nitride (CNx) films were grown on silicon substrates by ArF laser ablation (PLD) of a graphite target in presence of nitrogen at various gas pressures. These films have been measured by spectroscopic ellipsometry in the UV–vis and IR wavelength range. In the UV–vis range, the optical indices of the CNx films have been extracted accurately using a model including surface roughness. The optical indices of the films are modelized by a Forouhi dispersion law model and the thickness and roughness are adjusted at the same time. The optical gap is extracted from the extinction coefficient. In the IR spectral range, the conductivity of the films is extracted from the Drude tale model. These structural and optical results are compared to the physico-chemical results provided by Rutherford backscattering (RBS) and elastic recoil detection analysis (ERDA). [Copyright &y& Elsevier]

Abstract. Diamond-like carbon (DLC) films have been grown on Si substrates at ambient temperature by the pulsed-laser ablation technique, using pulses of different durations both in the nano- and picosecond ranges and at various energy fluences. The stability of these films was investigated as a function of thermal anneals performed in UHV conditions up to 1273 K. Their physico-chemical properties have been characterized by different techniques including X-ray photoemission, Auger electron and electron-energy-loss spectroscopies, Raman scattering, spectroscopic ellipsometry and atomic-force microscopy. The thermal stability of the films has been demonstrated to be related to their initial structural (sp[sup 3]/sp[sup 2] ratio) and chemical (contaminant) properties. DLC layers prepared under optimized conditions have been found to show a very good thermal stability up to 900 K. [ABSTRACT FROM AUTHOR]

Abstract. An ArF excimer laser (22 ns, 193 nm) and a hybrid dye/excimer laser system (500 fs, 248 nm) are used to deposit amorphous carbon nitride films at room temperature by ablation of a graphite target in nitrogen atmosphere. The chemical composition and structure of the films is characterized by X-ray photoelectron spectroscopy. In the nanosecond case, the nitrogen content increases with reactive gas pressure up to 45 atomic %, while in the subpicosecond case it remains below 7 at. %. When processed with nanosecond pulses, the films' nitrogen content steeply increases with fluence up to a maximum. The target-to-substrate distance has only minor influence on the amount of nitrogen incorporated into the films. The dependence of the carbon-carbon and carbon-nitrogen bond configurations on the processing parameters is also given. [ABSTRACT FROM AUTHOR]

Carbon films have been deposited by ArF excimer laser ablation of a graphite target in argon ambient of pressures between 10−4 and 200 Pa. Besides carbon, ex situ RBS and ERDA measurements reveal the presence of argon, hydrogen and oxygen in the films. Below 0.5 Pa the apparent growth rate, defined as the measured thickness per number of pulses, is almost constant at around 0.30 A˚ per pulse. Between 0.5 and 5 Pa it drops to 0.15 A˚ per pulse. The most salient feature of the pressure dependence is the unexpected increase in the apparent growth rate between 5 and 100 Pa. Above 100 Pa the growth rate further decreases below 0.07 A˚ per pulse. Parallel AFM measurements reveal characteristic differences in the surface morphology in each domain. Comparative analysis of the dependence of parameters characteristic of film growth and the evolution of microstructure on argon pressure provides information on the growth mechanism up to 200 Pa. [Copyright &y& Elsevier]