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An alternative to the currently existing elemental basis for creating dynamic random-access memory and flash memory is memristor structures, i.e., two-electrode systems, whose operation is based on the resistance switching effect. In this paper, the results of studying the specific features of the production of memristor structures on the basis of copper sulfide as a promising material providing high-efficiency performance of the structures are reported. The process of copper sulfurization is considered. In this process, the surface region of the copper layer is transformed into sulfide, and the remaining part of the layer is used as the active electrode for the later formed memristor structure. It is shown that, as the concentrations of the initial chemical reagents is increased, the surface roughness of the sulfide layer significantly increases. The sulfide growth rate at optimal initial concentrations of the chemical reagents is ~30 nm/min. In studies of memristor structures, it is established that, as the copper sulfide thickness is increased, the ratio between the resistances in the low- and high-resistance states increases from 11.2 to 12.5. In the memristor structures formed in the study, the time of switching from the high- to low-resistance state is about 1.3 μs, whereas the time of switching from the low- to high-resistance state is 0.9 μs.

In this paper, the study of the dynamic pyroelectric effect under different powers of modulated heat flux in deuterated triglycine sulfate (DTGS) near the Curie point is presented. It was f...

In this work, a process solution for the formation of an array of piezo- and pyroelectric structures with the use of a matrix of nanoprofiled silica is demonstrated. It is proposed to use plasma etching through a hard mask of porous anodic alumina for the formation of the matrix. Nanoparticles of a ferroelectric copolymer of vinylidene fluoride with trifluoroethylene are formed in the pores of the matrix. The results of measurements of the piezoelectric and pyroelectric responses of this structure are presented.

The frequency dependence of real (e′) and imaginary (e″) components of the complex dielectric permittivity has been determined for tin-thiohypodiphosphate Sn2P2S6 films in the temperature region from 150 to 400 K. There are two dielectric relaxation regions in the frequency range between 10−1 and 107 Hz. The high-frequency dielectric dispersion region at 103–107 Hz exhibits Debye type behaviour due to a semiconductor-metal interface barrier similar to a Schottky barrier. At low frequencies from 10−1 to 103 Hz, dielectric response is nearly a “flat loss” at least in the low-temperature region. At elevated temperature, the flat dispersion region disappears and a strong linear decrease of e″ (ω) is observed because of the dc conductivity.

In this paper we demonstrate a technological route for the formation of an array of memristor structures using a self-assembly matrix of porous anodic aluminum oxide. We propose using a porous alumina matrix as a solid mask to develop pores in the dense silicon oxide layer below the mask, in which a material characterized by the possibility of resistive switching is formed. The merit of this mask should include reproducibility and the high-precision control of geometric parameters of the pores. The current-voltage characteristics of a memristor structure based on solid electrolyte Cu2S are determined.

Improving the ways of magnetic structure investigation with the lowest possible resolution is important in the study and practical implementation of fundamental magnetism. Here we discuss one of the most modern magneto-optical method of domain structure (DS) imaging, scanning near-field magneto-optical microscopy (SNMOM), and propose the new technology based on focused ion beam (FIB) treatment to produce aperture cantilevers with carbon hollow pyramid tip (ACCT). Estimated ACCT light transmission coefficients show better results compare to commonly used aperture silicon cantilevers. By measuring the polarization characteristics of aperture with diameter from 83 to 263 nm, we illustrate the possibility of ACCT to maintain a liner polarization of transmitted light. Testing of ACCT in atomic-force and SNMOM modes shows that ACCT are the effective tool in near-field imaging. Features of morphology and DS of Bi-substituted iron garnet (Bi: IG) films synthesized and used as the test objects, including DS peculiarities of 100 nm-size, is revealed.

The preparation method of magnetoelectric multilayered ceramic heterostructures was suggested, and series of the rectangular and disk shape samples were produced on the base of this method. The maximum value of a magnetoelectric voltage coefficient αE = 35 V/(cm × Oe) was observed for the eleven-layered rectangular specimen at the electromechanical resonance frequency fr = 144 kHz, НDC = 84 Oe, and НAC = 2.5 Oe. The sensitivity to static magnetic fields is equal to 3.5 × 10−2 Oe, and the alternating field sensitivity is equal to 8 × 10−3 Oe.

Atomic force microscopy is one of the most popular method of investigation of samples surface at nanoscale. The most common problem of atomic force microscopy (AFM) is the obtaining real geometrical parameters during the studing of nano scale objects. Actually obtained AFM image is a “convolution” of images of the cantilever tip and the investigated object. This effect, called “image convolution” limits the resolution of AFM. Thus one of the most important task for researchers is to minimize this effect by reducing tip size. Classic microelectronic batch process allows to create hundreds AFM cantilevers simultaneously with tip curvature radius from 10 nm and more. Individual process methods (for example focused ion beam) allows to reduce tip radius down to several nanometers but for one cantilever per time only. Authors developed technology to reduce probes curvature radius by using defocused ion beam. The method could be used for both individual and batch processes. Basic principles of technology and results of its implementation are showed in this paper.

The work is devoted to the study of the formation of zinc oxide films in four different ways: by magnetron sputtering, deposition from the gas phase, by dip-coating, and by atomic layer deposition. The effect of alloying additives of subsequent thermal annealing on the morphology and electrical conductivity of the films obtained is reflected. It has been established that the smallest roughness of films is obtained when films are deposited by atomic layer deposition.

In this work experimental research results of silicon deep plasma etching features during 3D-TSV structure producing in inductively coupled plasma are presented. Silicon etching operational parameters influence (inductor RF power, working gas consumption) on process technological characteristics (Si etching rate, selectivity and etching profile) is investigated. Wherein passivation stage’s operational parameters were not changed and were constant. It is shown that microroughness in the form of microneedles and column structures can be formed on the bottom of formed structures at low RF power values; full stop of Si etching process can be also possible. It has been revealed that during polymerization stage fluorocarbon film’s deposition rate increase is observed on structure’s inclined surface in comparison with film’s deposition rate on vertical surfaces. At the same time fluorocarbon film’s deposition rate on the bottom of trench is higher than in inclined surface of the structure. Silicon surface after deep plasma etching process is studied. Fluorocarbon film’s adhesion to silicon and silicon oxide ability is researched. It is demonstrated that adhesion on test samples has small values or missing.

Certifying a transport airplane for the flights under icing conditions requires calculations aimed at definition of the dimensions and shapes of the ice formed on the airplane surfaces. Up to date, software developed in Russia for simulation of ice accretion and authorized by Russian certifying supervisory authority, is absent. The paper describes methodology IceVision recently developed in Russia for calculations of ice accretion on airplane surfaces. This methodology is implemented in CFD software FlowVision used by numerous companies and universities in Russia and abroad. The methodology differs from known approaches to simulation of ice accretion. In particular, changing the ice shape is calculated with use of technology VOF. This technology assumes calculations of continuous ice growth accompanied by local rebuilding the computational mesh. The implemented mathematical model provides capability to simulate formation of rime (dry) and glaze (wet) ice. Numerical solutions of validation test problems performed using methodology IceVision are demonstrated.Certifying a transport airplane for the flights under icing conditions requires calculations aimed at definition of the dimensions and shapes of the ice formed on the airplane surfaces. Up to date, software developed in Russia for simulation of ice accretion and authorized by Russian certifying supervisory authority, is absent. The paper describes methodology IceVision recently developed in Russia for calculations of ice accretion on airplane surfaces. This methodology is implemented in CFD software FlowVision used by numerous companies and universities in Russia and abroad. The methodology differs from known approaches to simulation of ice accretion. In particular, changing the ice shape is calculated with use of technology VOF. This technology assumes calculations of continuous ice growth accompanied by local rebuilding the computational mesh. The implemented mathematical model provides capability to simulate formation of rime (dry) and glaze (wet) ice. Numerical solutions of validation test problems pe...

A study of functioning of the magneto-optical method as part of magnetic force microscopy (MFM) is presented. Major errors in measuring the samples with MFM are discussed. The magneto-optical method enables us to perform a preliminary verification of a sample magnetic structure, providing minimal errors being specific for MFM. Design options for operation of the magneto-optical method as a part of MFM are proposed.

Scanning probe microscopy (SPM) is a widely used method for the different kind of objects investigation. It allows to obtain information about the surface topography including its mechanical and electromagnetic characteristics at nano scale. SPM also could be used for manipulation of nanoobjects. The most popular and widely used SPM methods are atomic force (AFM) and magnetic force microscopy (MFM). Both of them based on measuring interaction between sample and cantilever (probe). Type of cantilever its curvature radius, coating, resonant frequency, hardness and other parameters significantly influence on the SPM images. Scientist constantly improving process of probes producing to fit the current demands. It is important to keep in mind that collected AFM data could contain not only direct information about the sample but also it might be a convolution of the sample and cantilever in case then the tip size comparable with the studied object. Convolution effect limits the AFM resolution [1]. Thus one of the most important task for researchers is to minimize this effect by reducing tip size both for AFM and MFM methods.

In this work, pyroelectric properties of composite films on the basis of poly(vinylidene fluoride-trifluoroethylene) copolymer with a various level of ferroelectric ceramics inclusions of barium lead zirconate titanate solid solution were investigated by the dynamic method. The composite films were prepared by the solvent cast method. The unusual spike-like dynamic response with a quasi-stationary component was observed. It is supposed that composite films may be effectively used for pyroelectric applications.

We demonstrate application of integration scanning near-field optical microscopy and atomic force microscopy for investigation of magnetic and ferroelectric materials. This integration is made by using innovative optical and micromechanical components. Optical measuring head with cantilever holder was designed for both near-field optical microscopy and atomic force microscopy modes. Hollow pyramid cantilever with aperture at the tip was designed for registration both optical signal and tip=sample interaction forces. Cantilever aperture was made by ion beam at the center of pyramid. Same probe was used for both topography and domain structure visualization of magnetic samples. Bi: YIG-thin films topography and domain structure were investigated by this method as well as by conventional magnetic force microscopy (MFM). In integrated method of scanning nearfield polarization optical microscopy and atomic force microscopy samples were excited through cantilever aperture by tightly focused linearly polarized laser beam. Magneto-optical effect of the rotation of polarization plane of transmitted light depends on domain orientation. Visualization of magnetic domains was performed by detecting cross polarized component of transmitted light. Near field map of magnetic domains provides direct information of the magnetic moment of domains unlike MFM image which provides distribution of magnetic force gradient. Moreover, non-magnetic hollow-pyramid probe prevents sample from possible disturbances by internal magnetic moment of the MFM probe. Comparison of results obtained by near field polarization microscopy and conventional MFM was performed. We demonstrate possibility of investigation of topography and domain structure ferroelectric materials by integration method of near-field optical microscopy and atomic force microscopy.

In this paper the different digital phase-locked loop based structures and techniques to implement carrier recovery and data demodulation of high rate M-ary PSK signals are analysed. Costas and Square Loops are a main in the consideration. Methods to cope with inherent problems related to noise performance, settling time and lock range are discussed and corresponding algorithms are proposed. The Questions of handling Doppler-shifted carriers are also in subject.

Magneto-optical microscopy is a well-known and widely used method of magnetic domain structure investigation. Spatial resolution is limited by diffraction limit of the light and practically not exceed 0.5μm. Possibility to overcome diffraction limit by combination of magneto-optical microscopy and magnetic-force microscopy was showed earlier [1]. Aperture cantilever was used to light up the sample in near-field mode. In this paper, authors review most popular technology for aperture cantilever production with its advantages and disadvantages. Authors propose new technology based on focused ion beam treatment for creation aperture cantilevers with advanced parameters such as small aperture size and light throughput. Bi-substituted yttrium iron garnet (Bi: YIG) thin films with high magneto-optical activity and different period of domain structure were used as test objects. High resolution images of both morphology and domain structure obtained with new advanced aperture cantilevers are shown.

In this work, we have formed CuO memristive array embedded into porous SiO2 layer. Such an approach would create synaptic system on silicon substrate using standard integrated electronics operations. It also provides control over the geometric parameters of artificial synapses, which determines their synaptic weights. The results of synaptic behavior have shown that the value of synaptic weights and currents are dependent on the thickness of the CuO filled SiO2 porous layer.

The film structures on the base of soft and crystalline ferroelectrics (poly(vinylidene fluoride - trifluoroethylene) copolymer and deuterated triglycine sulfate) were produced. The volume content of the DTGS microcrystal particles embedded in the polymer matrix of the composite films was up to 10%. It was found crystalline phase changes in the polymer matrix at the DTGS inclusions presence. The DTGS crystal particles increased dielectric permittivity and electrical conductivity of the composite films. The temperature dependences of the dielectric permittivity indicated increasing the phase transition temperature of polymer matrix at the DTGS inclusions growth.

In the present work, the comparative study of the electric response of Sn2P2S6 films to the visible light action was carried out without and under external electric field. The light flux modulated by a chopper induces the integral response comprising time-dependent photoelectric and photovoltaic components. It was shown that spontaneous polarization influences the electric response characteristics.

The results of a study into the effect of cantilever structural parameters on the sensitivity of magnetic force microscopy (MFM) have been presented. It has been shown that it is necessary to use cantilevers with an optimal thickness of the magnetic coating and hardness of the beam lying in the range from 0.1 to 1.0 N/m in order to ensure the maximum sensitivity of the method. The use of these cantilevers makes it possible to register locally arranged single-domain iron particles ∼50 nm in size.

This paper presents the results of comparative analysis of the electrical and mechanical characteristics of the tungsten and tungsten alloyed with rhenium films deposited on silicon, from the point of view of their use as interconnects in silicon ICs. W and W (Re-5%) alloyed with rhenium films were made by magnetron deposition. Sheet resistivity for W and W (Re- 5%) was 13 and 27 μOhm·cm respectively. Elemental composition the formed films was examined by Auger spectroscopy. To investigate the electromigration resistance of the conductors a methodology based on the accelerated electromigration testing at constant temperature was used. A comparative analysis of the mechanical stresses carried out in the W and W(Re - 5%) films. For this purpose was applied non-destructive method for optical laser scanning. At the same time, these films explored their ability of adhesion to silicon and silicon oxide. It is shown that the pull force of the W(Re - 5%) films was ~1500 G/mm 2 , of the W films ~ 700 G/mm 2

The article dwells upon theoretical considerations on the nature of probe local anodic oxidation. The concept of the process presented here allows for the device intrinsic amperage limitations in the tip-sample system. The work also demonstrates characteristics of height-modulated dielectric mask formation on the solid-state surfaces.

The results obtained in a study of low-temperature methods for the synthesis of nanostructured titanium and zinc oxides are presented. It is shown that layers of porous titanium-oxide and zinc-oxide nanocrystals can be formed in a wide range of geometric parameters by varying the technological characteristics of the anodization process.

Functional capabilities of the scanning electrical-conductivity microscopy (SECM) in determining the electrical conductivity of nano-sized elements, studying the nanostructure of conductive coating materials, and evaluating the conductivity of nano-objects are described. The applicability of the SECM to finding imperfections in the multilevel metallization of integrated circuits with a nano-sized topology is demonstrated.

The method of three-passage measurements in magnetic force microscopy is described, which yields refined magnetic images of nano and microobjects, and eliminates the possible parasitic influence of long-range electrostatic forces while obtaining a magnetic image.

The features of formation of porous alumina masks for silicon nanoprofiling were investigated. The influence of micromorphology on the property of the local etching of silicon on the interface of an anodized double-layer structure of Al-Ti was shown. The correlation between the aspect ratio of alumina pores and the geometrical parameters of the porous silicon was investigated.

The specific features of the kinetics of local probe oxidation of ultrathin V, Nb, Ta, Ti, TiN, and W metal films are studied. It is established that the kinetics of the oxidation process depends on such properties of the material to be oxidized as the resistivity, the presence of a natural surface oxide film and its thickness, the relationship between the densities of the metal and oxide, and the electrochemical constant of the oxidation process. For the material that provides a high efficiency of formation of local insulator nanoregions, vanadium is chosen, since this metal exhibits the maximum rate of anodic probe oxidation.

A detailed analysis of the optimum regimes of pulsed current metal electrodeposition into pores of porous anodic alumina PAA is presented. A simple model based on cathodic and anodic current transients is developed. The model is based on a simplified equivalent circuit consisting of two capacities related to the barrier and porous parts of porous anodic alumina. Nanowires of Cd, Zn, In, Ni, Co, Ag, and Cu were embedded into PAA by pulsed electrodeposition using an asymmetric rectangular ac signal. Deposited metal nanowires were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), optical spectroscopy, Auger electron spectroscopy (AES), and X-ray diffractometry (XRD).

A test structure on the basis of nanoprofiled aluminum to determine the curvature radius of the cantilever tip is described. This structure was tested by studying tips with different geometries. The test structure allows one to determine the tip sharpness geometry with an accuracy of 2 nm.

The effect of design parameters, electrical properties, and technological modes of formation on the efficiency of the photoelectrical conversion of solar cells with extremely thin absorbing layers based on the SnO2:F/TiO2/In2S3/InxPb1 − xS/CuSCN is investigated. It is shown that both a decrease in resistance due to an increase in roughness and a decrease in the average grain size of the TiO2 films is attained with deposition using the sol-gel method under conditions of increased humidity. The use of Ni as the contact metal to a planarizing CuSCN layer provides the reduced value of the transient resistance. The optimization of the sequential resistance of the TiO2 film and contact resistance to the CuSCN layer provided an increase in the efficiency of photoelectric converters by a factor of more than four. The structures of solar cells formed in optimal technological modes showed the following characteristics: Jsc = 9 mA/cm2, Uoc = 720 mV, and they had an efficiency of 2.9%.

A copper sulfide and bismuth sulfide thin films were deposited on Si/Ti substrate by successive ionic layer adsorption and reaction method at room temperature, using cupric chloride, bismuth chloride, complexing Na2EDTA and sodium sulfide aqueous solutions as precursors. The surface morphology, structural and electrical properties of the as-deposited films were investigated by scanning electron and atomic force microscopy, energy dispersive X-ray analysis (EDS), and 2-point probe methods. The films were found to be amorphous, rough with thickness 30 nm and 20 nm for CuSx and BiSx, respectively. Average atomic percentage of Cu:S and Bi:S in the as-deposited films was calculated as 1:1.5 and 2.3:3. It was noted that films possess resistive switching behavior. Ionic conductivity of the CuSx film was found to be 25,8·10-3 Ohm-1·cm-1 . Ionic conductivity of the BiSx film was found to be 16·10-3 Ohm-1·cm-1. Set voltages UON defined by I-V curves were found to be in the range 0,75-0,8 V/cm for both films. Reset voltages UOFF were found to be in the range 0,6-0,7 V/cm for both films. Thus, formed films can be used as active layers for memory devices application.