Home – Home – Jornals – Advanced Search

The kinetics of reflectivity signals from nanostructures including an equal number of quantum wells with an identical composition In_xGa_1-xAs (x=0.32) with GaAs barriers of 2, 4, 6, and 8 monolayers grown over a semiconductor reflector under identical conditions are investigated by the pump-probe technique. The tendency of recovery time shortening for thinner barriers is found. The prospects of further research and practical application of quantum wells coupled via charge carrier tunneling are under consideration.

An analysis of the structure of as-deposited films of nonstoichiometric germanosilicate glasses and the transformation of their structure under annealing is carried out using the Raman spectroscopy and IR spectroscopy. It is shown that the structure of the films is stable up to a temperature of 350 ^oC; under annealing beginning from 400 ^oC, amorphous germanium clusters are formed in the films. On the basis of these films, metal-insulator-semiconductor structures are fabricated, and prospects for their use in memristors and photodetectors are demonstrated.

This work demonstrates that digital technologies can be successfully applied to image analysis and prediction of the properties of functional materials. As an example, a new method is used to rapidly identify the crystallographic orientation parameters in multicrystalline silicon. The proposed method is based on machine learning technologies. The analysis of textured multicrystalline silicon wafers is carried out using the original single-crystal grain clustering algorithm, and the crystallographic orientation parameters are identified using a neural network model. The principle of identification is based on the correlation of the contrast of the macrostructure display associated with the reflective features of the grains and their orientation parameters. The architecture of the neural network - a multilayer perceptron - is chosen taking into account the restrictions on the number of input data. However, in conjunction with the algorithm, the optimal amount of training data satisfies the requirements of the neural network training process and ensures high efficiency in identifying orientation parameters on scanned images of textured multicrystalline silicon wafers.

The field dependence of the magnetization of a silicon nanosandwich, observed at room temperature, demonstrates a very complex character. The dependence is formed by the main contribution of the quantum magnetic effect, which is interpreted as the de Haas - Van Alphen effect with integer and fractional filling factors. Based on the previously found two-dimensional carrier density, the critical fields for the corresponding filling factors are calculated. Modeling of the de Haas - Van Alphen oscillations at a high temperature (T = 300 K) is performed according to a given distribution of the energy density of states of a silicon nanosandwich in the vicinity of Landau levels. The computational procedure is implemented on a supercomputer. The dependence of the carrier effective mass on the strength of the external magnetic field, previously discovered by us, is taken into account.

This work presents the Monte Carlo simulation results of gold droplet movement over a vicinal Si(111) surface during the gold deposition. The behavior of gold droplets on a singular silicon surface with (111) and (100) orientations is considered. It is found that the directional droplet motion on the vicinal Si(111) surface is caused by the asymmetry of lateral facets at the liquid-crystal interface. The asymmetry of lateral facets is caused by the presence of steps on the vicinal Si(111) surface. The reason for the gold droplet movement is the silicon substrate dissolution in the tendency to reach the Au-Si melt equilibrium concentration in the droplet bulk. The kinetics of Au-Si droplet movement on the silicon surface is analyzed.

One of the promising approaches to solving the problem of producing low-cost photodetector arrays is to develop diode arrays based on structures with PtSi/poly-Si Schottky barriers produced by standard CMOS processes. In creating such structures, several problems arise, and the present study is aimed at solving such problems. The diffusion of hydrogen atoms from a Si₃N₄ layer into a silicon film at room temperature at the step of formation of a Si/Si₃N₄ layer is detected and studied using Fourier-transform infrared spectroscopy. In studying the formation of PtSi/poly-Si layers, it is found that an interface film consisting of Pt₃Si and Pt₂Si silicides is formed on the surface of poly-Si during magnetron sputtering of platinum. When the Pt/(Pt₃Si+Pt₂Si)/poly-Si structure is heated to ∼ 300°C for 30 min, the transition of the Pt₃Si phase to the Pt₂Si phase occurs. A further increase in temperature leads to the formation of the PtSi compound; at the temperature of 480°C, all silicides completely transform into the PtSi phase.

The effect of coatings containing dysprosium or erbium ions on the properties of photosensitive structures based on porous silicon is investigated. The current-voltage, capacitance - voltage and spectral characteristics of structures with a p-n junction and films of erbium or dysprosium fluorides, as well as structures with an oxide layer of a complex composition containing erbium ions, are measured. The effect of X-ray radiation with a quantum energy of 6.9 keV on the photoelectric properties of structures with a porous layer and a coating of erbium fluoride is studied. A noticeable effect of the coating on the characteristics of the structures is shown.

The photoluminescence of float-zone silicon irradiated with high-energy xenon heavy ions (167 MeV) has been studied. In the photoluminescence spectra at low temperatures, in addition to the known X, W, W’, and C lines, a wide band appears in the region of 1.3 - 1.5 µm. With an increase in the irradiation dose in the range of 5·10¹⁰ - 10¹³ cm^-2, a decrease in the intensity and narrowing of the photoluminescence band is observed with a simultaneous shift of the maximum to the long-wavelength region. During subsequent annealing at temperatures of 400, 500, and 600 ^oC, changes in photoluminescence spectra are observed, associated with the transformation of the structure of defects in silicon. The temperature dependence of photoluminescence in the range from 10 to 170 K is studied for samples after irradiation with various doses and annealings.

The knowledge of the photoresist refractive index is useful for a number of applied tasks of controlling microelectronics technological processes, as well as for experimental studies of the characteristics of prototyped diffractive and micro-optical structures with deep microrelief. As this optical parameter depends on the photoresist treatment conditions, the spectral dependences provided at times by manufacturers may be insufficient. Research results of determining the refractive index dependence of positive photoresists S1818 G2 (MICROPOSIT) and FP-3535 (FRAST-M) in the wavelength range of 500-1600 nm on preliminary heat treatment conditions in the range of 15-30 min and exposure to actinic radiation are presented. The treatment of the investigated photoresists to obtain the refractive index within 1.61-1.64 in the visible spectral range and 1.59-1.61 in the near infrared spectral range of the emission spectrum is provided. An anomalous dispersion zone in the 570-640 nm wavelength range has been detected in films of the S1818 G2 dyed photoresist, which is often used in experimental characterization research in diffractive optical element prototyping. The dispersion curves for the Russian photoresist FP-3535 have been obtained for the first time.

The Spatial Development Strategy of the Russian Federation until 2025 provides Russian regions with the choice of prospective economic specializations, which are often summarized in the concept of “smart specialization." One of such prospective specializations is financial and insurance activities. An analysis of existing approaches to defining regional specialization has revealed the possibility of including financial and insurance activities as specializations of Russia’s individual constituent entities. Detailed statistical material on prospective economic specializations, including financial services and insurance, is defined in the Atlas of Economic Specialization of Regions. The object of observation is the Siberian Federal District and its five constituent entities (Altai Republic, Altai Krai, Krasnoyarsk Krai, Kemerovo Oblast, Novosibirsk Oblast), which have chosen financial services and/or insurance as their branches of specialization. We propose a methodology for ranking the capabilities of financial market participants in these constituent entities of the Rassian Federation. Based on the developed methodology, the city of Novosibirsk has been considered a potential capital of the regional financial market of Siberia. Using the main elements characterizing institutional and instrumental approaches to the formation of the financial market, we suggest the ways of creating a regional financial center in Novosibirsk.