Deposition of pure and Ge-doped silica as well as silicon oxynitride films has been studied in a recently developed matrix distributed electron cyclotron resonance (MDECR) reactor. Process parameters were optimized in order to obtain optical quality thin films at low substrate temperatures and high deposition rates without post-deposition treatment. The choice of injection system is shown to be of crucial importance for the deposition of high quality materials in low pressure PECVD. It has been found that injecting silane near the surface allows to obtain films with a low OH absorption independently of silane flow i.e. growth rate in a certain range of process parameters. On the contrary, in the case of uniform distribution of silane in the reactor volume the hydrogen content increases with silane flow, which affects the quality of films deposited at higher rates. With the optimized injection system, stress-free silica films with a low absorption have been deposited at the rates up to 70 nm/min at temperatures lower than 150 °C. Non-absorbing oxynitride films with a controllable refractive index ranging from 1.46 to 1.86 have been obtained from SiH4/O2/N2 mixtures. Ge-doped silica films with a Ge content of up to 4% has been deposited using a mixture GeH4 in H2 as a dopant. The properties of deposited films have been studied as a function of process parameters. The results show that the MDECR concept, that permits, in principle, unlimited scaling of substrate size, can be technology of choice for the deposition of optical thin films and functional coatings.

Results of experimental investigation of powerful microwave beams action on the metal-dielectric compositions are presented. Dielectric surfaces with introduced metallic grains as well as dielectric powder containing small admixtures of a metallic one have been explored as an objects of irradiation. At a relatively small microwave power ($P \le 1$ mW) all investigated targets were practically completely transparent for incident electromagnetic wave. At a relatively high power (microwave generators based on the gyratrons and powerful magnetrons) the irreversible changes in the electric and radiophysical properties of metal-dielectric composites exposed to microwave radiation whose intensity is below the threshold intensity for plasma production have been observed (sharp increase of conductivity and microwave absorption coefficient).

We present a detailed study of the structure and hydrogen bonding in silicon thin films ranging from amorphous to microcrystalline. We emphasize the results for hydrogenated polymorphous silicon films obtained under plasma conditions close to powder formation where silicon clusters and nanocrystals contribute to growth. Fourier Transform Infra-Red (FTIR) spectroscopy, Raman spectroscopy, X-Ray-Diffraction (XRD), and hydrogen evolution measurements are performed to characterize the hydrogen bonding and the structure of the films in their as-deposited state and after isochronal annealing at increasing temperature in the range of 300 to 600 °C. While Raman spectroscopy and XRD give an average information on the structure of the films, without clear evidence of the presence of crystallites in the polymorphous films, infrared spectroscopy and hydrogen evolution measurements which probe the local hydrogen related structure are shown to be perfectly adapted to characterize polymorphous silicon films. In particular, IR spectroscopy measurements, reveal the presence of a stretching band at 2030 cm−1, associated with a peak at 873 cm−1 in the bending region and a downward shift in the Si-H wagging mode from 640 cm−1 to 622 cm−1. We attribute the 2030 cm−1 mode to the presence of hydrogen bonded at the surface of the plasma produced silicon clusters and nanocrystals. This assignment is supported by hydrogen evolution measurements in which a sharp low-temperature hydrogen evolution peak appears at around 420 °C followed by up to five peaks at higher temperatures. This particular hydrogen bonding in polymorphous silicon films is also supported by isochronal annealing studies which show that the bands at 2030 cm−1 and 873 cm−1 vanish at annealing temperatures corresponding to the low temperature hydrogen evolution peak. Based on these results and their correlation with the hydrogen-related material structure, we propose a picture for the structure of polymorphous silicon films that accounts for the observed features.

Films are used in a wide range of electronic and mechanical technologies. An analytical solution is developed in this paper in order to investigate the effect of films on the thermal behavior at the vicinity of a static or moving rough interface. The roughness is modeled by multiple circular contacts which are assumed identical and regularly distributed over the interface according to a square net. The governing equations are solved by using the finite complex Fourier transform and the finite cosine Fourier transform. The developed solution is explicit and allows to calculate the three-dimensional steady-state temperature regardless of the velocity and the ratio of the real contact area to the apparent one. Thus, this solution can be also used for other applications such as the moving laser beam. The comparisons performed show a good agreement of our results with available models. We study the effects of: thermal properties of materials, the relative size of micro-contacts, the film thickness and the velocity, on the thermal behavior of the body.

Near-field optical signals are imaged in the vicinity of nano-holes using two different near-field optical microscopes. The experimental results are compared with electromagnetic field calculations based on a modal approximation. It turns out that an optical fibre detects the Poynting vector whereas the apertureless tip is sensitive to the field amplitude.

A realistic near-field calculation on metallic hole samples in illumination transmission conditions predicts certain light confinements around the holes. The purpose of this paper is to explain theoretically how an A-SNOM (Apertureless Scanning Near-field Optical Microscope) is able to detect the light confinement around the holes, and how it is possible, by defining a criterion of separation between two holes in near-field, to analyse the resolution as a function of the experimental parameters. The modulation of the probe height in A-SNOM is used for both distance control and separation of the near-field from the background scattered light. A realistic model of lock-in detection is used to calculate the images of test samples. Constant height mode images are presented at different amplitudes of probe modulation and average heights of the tip. We also discuss the detection at different demodulation harmonics.

On the basis of experimental measurements of the electric field (which varies from 5 to 60 V/cm) and the N-atom relative density variation (one order of magnitude), mechanisms of ionization and dissociation in direct current glow discharges are discussed for pressures ranging from 0.5 to 5.0 torr and current between 1 and 50 mA. It is shown that: (i) at low pressure (E/N > 40 Td) ionization is governed by electronic impact and Penning reactions; (ii) at high pressure (E/N < 40 Td) the ionization is mainly governed by Penning reactions.

A N2 direct current discharge was studied by optical emission spectroscopy. Experimental parameters as gas flow rate (Q), pressure (p) and current (I) were varied independently, covering the following range: 10 < I < 75 mA, 100 < Q < 1000 sccm and 1.7 < p < 10 torr, corresponding to the following plasma parameters: electron density in the range 109−1012 cm−3 and reduced electric field between 3×10−16 and 10−15 V cm−2. The N2(C $^{3}{\rm \Pi} _{\rm u},\,v'$), N2(X $^{1}{\rm \Sigma} ^{+}_{\rm g}, \,v$) vibrational temperatures and the gas temperature were obtained from the first and second positive systems emissions. The N2(C $^{3}{\rm \Pi} _{\rm u},\,v'$) vibrational distributions did not exhibit a Boltzmann character. A linearization process was employed to such distributions allowing us to calculate the N2(C $^{3}{\rm \Pi} _{\rm u},\,v'$) temperature. The N2(X $^{1}{\rm \Sigma} ^{+}_{\rm g},\,v$) temperature was calculated from the N2(C $^{3}{\rm \Pi} _{\rm u},\,v'$) one on the basis of the Franck-Condon factors. Results and the method of vibrational temperature calculus are presented.

A new technical approach of a traditional method for the rapid (and therefore, non interfering) determination of the thermophysical properties of porous materials likely, a priori, to undergo coupled heat and moisture transfers is described. The improvements discussed here consist in the use of a heater film suiting the “method of the hot plane film” especially well. A comparison with former works by one of the method's author is made. Finally, the updated method is applied to a variety of particularly significant materials.