Vestnik Rossijskij fond fundamentalʹnyh issledovanij

In this work, the critical properties of a periodic mesoporous organosilicate dielectric with different ratios of benzene bridging and methyl groups are studied using various modern methods, such as ellipsometric porosimetry, surface acoustic wave spectroscopy, X-ray reflectometry, and others. It is shown that the pore size and surface roughness of the films decrease with an increase in the concentration of benzene groups, although at a concentration of >25 mol.%, the pore size sharply decreases and changes little with a further increase. With an increase in the concentration of benzene groups, the dielectric constant also increases and the mechanical properties improve. The increase in Young's modulus has a percolate behavior and increases sharply at a concentration close to 50 mol.%. It was found that the introduction of 30 wt.% porosity in films with benzene groups, in which there are no methyl groups, leads to an increase in Young's modulus. This behavior is associated with the formation of a crystal-like structure on the film framework. An increase in the dielectric constant is associated with the greater polarizability of benzene groups compared to methyl groups, as well as with their greater hydrophilicity and the presence of adsorbed water.

Ruthenium thin films were deposited by plasma enhanced atomic layer deposition (PEALD) using Ru(EtCp)2 and oxygen plasma on the modified silicon surface and SiO2/Si substrates. The substrate temperature has a significant impact on film growth. The GXRD and SIMS analysis have shown that at the substrate temperature T=375 °C there is a sharp change in the mechanisms of surface reactions, which leads to a change in the film composition from RuO2 at low temperatures to a pure Ru film at higher temperatures. This was confirmed by measurements of the electrical resistivity of Ru-based films. The lowest surface roughness ~1.5 nm was obtained at a film thickness of 29 nm deposited at 375 °C on a SiO2/Si-substrate. The measured resistivity of the Ru film was 18–19·μΩ∙ cm. Issues regarding the plasma-chemical etching of ruthenium and the spin-on of a low-k dielectric onto arrays of lines are taken into account.

Understanding the detailed mechanisms of the action of active radicals on SiOCH nanoporous dielectrics with low permittivity k used as interlayer SiOCH low-k dielectrics in a new generation of integrated circuits is important for developing recipes for reducing the degradation of low-k dielectrics in technological processes of plasma-chemical processing. In this work, the features of these mechanisms of interaction of fluorine, nitrogen, and oxygen atoms with low-k dielectrics with different pore sizes and degrees of porosity are studied experimentally and theoretically. The samples were treated at low temperatures with O, N, and F atoms in plasma downstream of an inductive discharge in O2, N2, and SF6 gases, respectively. Lowering the temperature led to different (for different atoms) slowdowns in the degradation of surface CH3 groups, which ensured the hydrophobicity of the porous medium and low-k values of dielectrics. An analysis of the results obtained using DFT (density functional theory) calculations and ab initio MD (molecular dynamics) modeling of reaction mechanisms revealed branched reactions of atoms with surface Si–CH3 groups and with other sequentially formed groups.

This paper presents the study results of an RF non-self-sustained plasma discharge with additional ionization by electron beams. Using a complex experimental-theoretical approach it was shown that the parameters of such plasma differ from those of a conventional RF plasma as well as pure electron beam plasma. The study has confirmed that RF plasma with electron beam ionization can be used to obtain a lower electron temperature than in classical RF plasma and, accordingly, to obtain lower energy ions. RF non-self-sustained discharge plasma parameters can be controlled: plasma density – by varying the RF power at the discharge generation frequency; energy spectra of electrons and ions – by varying the contribution ratio of the RF power, the RF-bias power, and the electron beam power. The result obtained is also promising for the possibility of precision surface treatment with low ion energy plasma used in atomic layer etching and deposition technologies.

The article presents the developed methods for studying the dielectric response function of thin films in heterostructures. Particular attention is paid to the technique dealing with moisture-saturated porous thin films. The vibrational absorption bands are parametrized and their contributions to the total dielectric permittivity are determined. The vibrational absorption band in the THz range of organosilicate glasses was analyzed and the effect of moisture saturation and boson peak of an increase in low-frequency dielectric permittivity of at least 10% was revealed. The developed methods are used to restore the optical characteristics of a transparent conducting oxide film of lanthanum nickelate in the THz range.

The review of the RFBR project results in the field of synthesis, research and modeling of magneto-optical films and film nanostructures for оn-сhip monolithic integration of non-reciprocal photonic devices is given. Based on the results of studies of nano- and picosecond processes in magnetic films – the dynamics of spins in a monodomain film and the dynamics of domain walls in a multi-domain film, the possibilities of developing high-speed optics-on-chip devices, including devices of the terahertz frequency range, are considered.