Problem statement. Development of methods for producing large-area isolated graphene under controlled conditions is an important task, which is primarily interested in the unique physical and chemical properties of graphene: high electrical and thermal conductivity, dependence of electronic characteristics on the presence of attached different radicals on the graphene surface, adjustable band gap, and high carrier mobility. Goal. It is necessary to develop regimes for producing thin graphite films on a dielectric substrate by annealing the structure (0001)Al2O3/(111)Ni/ta-C with a minimum density of defects in the crystal structure by the heteroepitaxial synthesis method. Results. The method of obtaining thin graphite films on a dielectric substrate by annealing the structure (0001)Al2O3/(111)Ni/ta-C has been tested. The method is based on the catalytic decomposition of hydrocarbons on the single crystal surface of a metal catalyst, diffusion and crystallization of carbon on the reverse side of the metal film. The surface of the obtained carbon films with a thickness significantly exceeding one atomic layer is uniform within the 5x5 mm samples. Varying the annealing temperature and time, as well as the initial amount of carbon, will further allow to control the amount of carbon involved in the formation of atomic layers. Practical significance. The described method is promising for developing a scalable technological process for obtaining largearea graphene on a dielectric substrate.

Nanoribbons from different materials, such as graphene and topological insulators, are currently intensively studied as structures needed in nanoelectronics and spintronics devices. Consequently, it is important to consider the technology that would allow one to produce such structures with the best achievable space homogeneity and perfect crystal structure. We studied the possibility to increase the homogeneity of etching “microwire-on-insulator”-type structures. The studies were carried out by computer simulations and by technological experiments. It was shown that modulating the potential of the substrate by a noise-like signal can significantly increase the quality of the profile of the cross section of the ion beam that exits from the plasma toward the structure in the plasma processing reactor with a remote plasma source. To do this, we designed and tested the source of noise-like signal and carried out experimental etching of test ribbons from nickel film. These experiments confirmed the efficiency of the proposed method.

The process and applications of a specific type of gaseous discharge—beam–plasma discharge (BPD)—are reviewed. A brief survey of the BPD theory is presented. The basic features of BPD in active geophysical experiments with injection of electron beams into Earth’s ionosphere are discussed. Studies of the physics of BPD have revealed the effects successively applied in plasma technology for processing nanoelectronic materials and structures.

A technique for growing thin graphite films on a dielectric substrate by annealing the Al 2 O 3 (0001)/Ni(111)/ ta -C structure has been optimized. This technique is based on catalytic decomposition of hydrocarbons on the surface of a single-crystal catalyst metal film on a dielectric substrate and subsequent diffusion and crystallization of carbon between the metal film and the substrate. A thin graphite film with a low density of crystal-structure defects is obtained on the dielectric substrate after chemical etching of the metal film.

Results are presented of the particle-in-cell numerical simulations by the KARAT code of the formation of a plasma–beam discharge in the absence of both the longitudinal magnetic field and the initial plasma. Oscillations of the electric field generated by the plasma–beam instability in the electron beam region almost do not affect the plasma at the periphery of the system. Simulation results are compared to the results obtained earlier by a simplified model and to the results of test experiments. The spatial distributions of the plasma density and electron temperature qualitatively agree with the experimental results.

The results of testing the methods of preparation of thin graphite films on a dielectric substrate by the method of annealing the structure of (0001) Al2O3/(111) Ni/ta-C are present. The method is based on catalytic decomposition of hydrocarbons on the surface of the monocrystalline film of the metal-catalyst on the surface of the dielectric substrate and subsequent diffusion and crystallization of carbon between the metal film and the substrate. After chemical etching of the metal film, a thin graphite film with low density of crystal structure defects on a dielectric substrate is obtained.

The technologies developed at V.A. Kotelnikov Institute of Radio Engineering and Electronics of RAS for specific application in nanoelectronics that are not used in industry are reviewed. Physical problems that were been solved at their development are analyzed, and found solutions are represented. Tested applications are briefly described.

We investigate the action of ion flows from a plasma onto the surface of a flat conductor lying on an insulator, with width less than the plasma Debye length. The model allows study of the processing with a steady state or pulsed potential on the microwire. The shape of pulses has been synthesized to provide the most homogeneous distribution of the etching rate over the microwire surface.

The results of experiments on the production of nano-crystalline graphite films in the hollow cathode discharge on Ni(111)/sapphire substrate are presented. The characteristics of the discharge for different gases and pressures are given. The emission spectra of the plasma have been measured. The layers of the deposited graphite have been characterized by the methods of Raman scattering and atomic force microscopy. The field emission of nano-crystalline graphite was also measured. The produced layers have good homogeneity and high value of the electron field emission. The presence of vertically growing graphene is revealed.

Results of particle-in-cell simulation of the formation of a near-wall plasma layer produced by an ionization source remote from the chamber walls are verified experimentally. The measured profiles of the density and temperature of the plasma produced by an electron beam in two modes are compared: (i) gas is ionized by a low-density electron beam, while collective interactions are almost absent (beam-induced plasma), and (ii) gas is mainly ionized by plasma electrons heated due to the development of two-stream instability (beam−plasma discharge). The measured spatial profiles of the parameters of the beam-induced plasma are found to qualitatively agree with the model ones.

Синтез пленок нанокристаллического графита в разряде с полым катодом

Experimental results on the synthesis of thin graphite films with the aid of annealing of nickel films on carbon substrate are presented. Highly oriented pyrolitic graphite is used as the substrate to provide structural quality of the deposited nickel film. It is shown that the cyclic annealing of the structure with intermediate cooling leads to crystallization of primary amorphous carbon into a film consisting of flakes of vertical graphene. The process of graphite formation is discussed.

A technique for depositing single-domain heteroepitaxial nickel films onto sapphire substrates is presented. It is demonstrated that high-temperature annealing of these substrates in oxygen alters their near-surface layer in a way that enables the growth of single-domain heteroepitaxial (111) Ni films on a (0001) Al2O3 substrate. Single-domain heteroepitaxial (111) Ni films on a (0001) Al2O3 substrate, which can be taken as the basis for a technique for fabrication of large-area single-crystalline graphene films, were synthesized for the first time.

A model is constructed allowing computer simulations of the near-wall area of a planar plasma sheet in conditions where the steady state of the plasma is supported by the production of charged particles in a region removed from the wall. Calculations have revealed variation in the energy distribution of the electrons in both time and spatially over the sheet width (cooling the electronic component) due to absorption of fast electrons at the walls bounding the plasma volume. It is shown that the plasma density profile across the sheet width has an abrupt decrease at the boundary of the region of plasma regulation. Thus the standard concepts of the potential and plasma density distributions in the sheath and presheath based on the assumption of a stable energy distribution for the electrons in the presheath yields inaccurate results for the plasma sheet where the ionization source is remote from the wall.

The review considers plasma-processing technologies used in solid-state electronics, both widely used and ones, which do not found yet industrial applications. Several from them are developed specifically for creating nanoelectronic devices. Tendencies toward an increase in the working rate and memory volume and a decrease in the sizes of telecommunication systems necessitate the development of electronic devices based on new principles and, hence, the corresponding technologies for implementation. Physical problems that impede the application of conventional methods in new problems are analyzed, and possible solutions are proposed.