Laser-induced fluorescence has been used to examine the temporal behavior of ground-state CF2 and CF radicals in a CF4 plasma etching reactor. We also report the measured spatial dependencies of the radical concentrations, and develop a rigorous model for their interpretation. The results indicate that for CF2 and CF, wall removal processes are dominant at low pressures of the order of 50 mTorr, and that CF is not produced by electron impact dissociation of CF2.

Laser induced fluorescence has been used to detect ground-state CF and CF2 radicals in a CF4/O2 plasma etching reactor. Measurements are reported of the spatial variation of CF2 concentrations, of the CF radical rotational state distributions, and of the variation of both species with O2 content of the plasma.

This paper presents a theoretical study showing the mechanism of light transmission through opaque metallic films perforated with nanocoaxial apertures thanks to the excitation of their cutoff-free TEM (Transverse ElectroMagnetic) guided mode. Full three-dimensional Finite Difference Time Domain (3D-FDTD) together with a Body-Of-Revolution FDTD simulation results are presented and discussed in order to optimize this extraordinary transmission. Very promising findings are pointed out opening the path to the design of new devices for both nano-optic and photovoltaic applications.

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Laser induced fluorescence of CF2 has been observed in plasmas of CF4 and its mixtures with O2 and H2. Surface removal rates of the radical in pure CF4 were measured by observing the decay of the radical when the plasma is switched off. The reduction in CF2 concentration, and the increase in F atom concentrations (the latter measured by optical emission spectroscopy) on the addition of O2 is reproduced by a model of the plasma in which gas phase chemical reactions play a dominant role. The increase in CF2 concentration on the addition of H2 to a CF4 plasma is shown to be due to a reduction in the surface removal rate.