This PDF file contains the front matter associated with SPIE Proceedings Volume 10224, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.

Electrical properties of MOS structures based on molecular beam epitaxy formed HfO₂/Pr₂O₃ gate dielectric stacks have been studied by CV, GV and IV characteristics. Electrical properties of the structures with HfO₂/Pr₂O₃ and PEALD HfO₂ dielectric layers were compared. Higher gate leakage current and lower interface trap level density in the structure with HfO₂/Pr₂O₃ dielectric layer was observed.

This paper is dedicated to the experimental investigation of Ohmic contacts to the n+-doped region of AlGaN/GaN transistor heterostructure based on Ti/Si/Ti/Al/Ni/Au metallization. Effect of annealing temperature on the specific resistance of Ohmic contact was studied. Ohmic contact with the resistance of 3.4·10^-6 Ω·cm² was formed by optimization of the annealing temperature and introduction of the additional doping silicon layer.

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/mm², of the W films ~ 700 G/mm²

In this work we provided a review of the study of MACE (metal-assisted chemical etching) of Si with Ag, Pt, Ni and Au films and clusters. Type and shape of the metal mask play an important role in determination of morphology of the nanostructured layer. It is possible to form both wide range of porous layer and nanowires array. The basic features of the MACE with various types and shape of the metal were revealed.

Mechanical properties of freestanding Au-Mn nanowires and Au-Mn nanowire on a Cu (110) substrate are studied with ab initio theoretical approach. The calculations were carried out using the software package Vienna Ab-initio Simulation Package (VASP), which is based on the density functional theory (DFT). It was shown that the breaking force (0.45nN) as well as the interatomic distance at a breaking point in bimetallic nanowire (3.0 Å) are higher than in one component Au wire (0.4 nN and 2.6Å respectively). Relative elongation of 15 % results in a fracture of bimetallic nanowire.

We studied the mechanical response of the nanojunction in a form of three-atomic Au chain aligned vertically between two pyramidal gold electrodes and demonstrated that the breaking of nanocontact depends only the interaction between Au atoms in the chain and dependents slightly on the structure and properties of the atomic structure of the electrodes.

Ultrathin (1–10 nm) Cu and Au films were prepared on the silicon and quartz substrates by magnetron sputtering at room temperature. We measured the transmission coefficient of the films at a wavelength of 3cm and analyzed a surface morphology of these films. It was shown that the films with thicknesses less than 7.5 nm (Au) and 3 nm (Cu) are almost transparent for microwaves. This effect is explained by quick oxidation of Cu and the complex surface morphology of nanometer thick films. The Au film morphology is evolved with increasing average Au thickness d from hemispherical islands initially (1.0 nm<d<5.0 nm) to partially coalesced worm-like island structures (d=10 nm).

The optical properties of Ag ultrathin films in dependence of their thickness are studied theoretically in a wavelength range 0.3 - 10 μm. The extinction coefficient (k) and refractive index (n) for thin Ag films with smooth surface structure are calculated with software package VASP. It was found the effect of growth of extinction coefficient and shift of its peak into long wavelength range with the thickness increasing. The effect is explained by the significant increasing of the surface electron states. Refractive index n is increased with the wavelength growth and attains saturation value n_s at the wavelength λ_s. The thicker the films the higher the magnitude of n_s and the larger the wavelength λ_s. Our results of calculations of k(λ) are in a good agreement with experimental data from ref.[25]. The difference in magnitudes of n obtained experimentally and theoretically can be explained by the formation of Ag nanoclusters on the surface of sputtered film.

In this work the superposition of effects with different diffraction origins and orders by formation of resulting magnetooptical response from the structures like magneto-photonic crystals in the regions far from plasmonic resonances were investigated for the first time. The contributions into magneto-optical response from diffraction and interferential phenomena in maxima of different orders in three-dimensional systems like magneto-photonic crystals were studied. It was demonstrated that the usage of integral response in order to analyze magneto-optical effects results in disappearance of interference phenomena. Diffraction maximum of the zero order reflects represent magnetic component of magnetooptical response. Numerical evaluations of observed effects were done.

Bismuth ferrite, a widely studied room temperature multiferroic, provides new horizons of multifunctional behavior in phase transited bulk and thin film forms. Bismuth ferrite thin films were deposited on lattice mismatched LaAlO₃ substrate using pulsed laser deposition technique. X-ray diffraction confirmed nearly tetragonal (T-type) phase of thin film involving role of substrate induced strain. The film thickness of 56 nm was determined by X-ray reflectivity measurement. The perfect coherence and epitaxial nature of T- type film was observed through reciprocal space mapping. The room temperature Raman measurement of T-type bismuth ferrite thin film also verified phase transition with appearance of only few modes. In parallel, concomitant La and Al substituted Bi_1-xLa_xFe_0.95Al_0.05O₃ (x = 0.1, 0.2, 0.3) bulk samples were synthesized using solid state reaction method. A structural phase transition into orthorhombic (Pnma) phase at x = 0.3 was observed. The structural distortion at x = 0.1, 0.2 and phase transition at x = 0.3 substituted samples were also confirmed by changes in Raman active modes. The remnant magnetization moment of 0.199 emu/gm and 0.28 emu/gm were observed for x = 0.2 and 0.3 bulk sample respectively. The T-type bismuth ferrite thin film also showed high remnant magnetization of around 20emu/cc. The parallelism in magnetic behavior between T-type thin film and concomitant La and Al substituted bulk samples is indication of modulation, frustration and break in continuity of spiral spin cycloid.

Principal difference of magnetic nanoparticles from the bulk matter which cannot be ignored when constructing upon them combined metamaterials and modern devices is the essential influence on their behavior thermal fluctuations of the environment. These disturbances lead to specific distributions of the particles characteristics and to stochastic reorientations of their magnetic moments. On the basis of quantum-mechanical representation of the particle possessing intrinsic magnetic anisotropy and being placed onto the external magnetic field we developed general approach to describe equilibrium magnetization curves and relaxation Mössbauer spectra of magnetic nanoparticles for diagnostics of magnetic nanomaterials in the whole temperature or external field ranges. This approach has universal character and may be applied not only to the systems under thermal equilibrium, but may in principle describe macroscopic dynamical phenomena such as magnetization reversal.

The structural and optical properties of Ge and GeSi nanocrystals, formed by annealing of GeO/SiO₂ multilayers have been investigated. According to Raman spectroscopy, the formation of pure Ge nanocrystals is observed after post growth annealing at 700 °C. Annealings at 800°C-900°C leads to the formation of intermixed Ge_xSi_1-x nanocrystals. High resolution transmission electron microscopy shows that the structure and the size of the nanocrystals strongly depend on annealing temperature. Spatial redistribution of Ge with the formation of large faceted clusters located near the Si substrate as well as GeSi intermixing at the substrate/film interface were observed. In the case of the sample containing 20 pairs of GeO/SiO₂ layers annealed at 900 °C, some clusters exhibit a pyramid-like shape. FTIR absorption spectroscopy measurements demonstrate that intermixing between the GeO and SiO₂ layers occurs leading to the formation of a SiGeO₂ glass. Low temperature (10 K-100 K) photoluminescence was observed in the spectral range 1400-2000 nm for samples containing nanocrystals. The temperature dependence of the photoluminescence is studied.

Silicon nanocrystals and germanium nanolayers and nanocrystals were created into i-layers of p–i–n structures based on thin hydrogenated amorphous silicon films. The nanocrystals were formed using pulsed laser annealing with an excimer XeCl laser generating pulses with the wavelength of 308 nm and the duration of 15 ns. The laser fluence was varied from 100 (that is below the melting threshold) to 250 mJ/cm² (above the threshold). The laser treatment allowed the formation of the nanoscrystals with the average size from 2 to 5 nm, depending on the laser-annealing parameters. The size of nanocrystals (in Si and Ge layers) and their Si-Ge composition (in GeSi alloy structures) was estimated through Raman spectra analysis. The structural parameters of Si, Ge and GeSi nanocrystals were also studied using electron microscopy and atomic force microscopy. Current–voltage measurements showed that the p–i–n structures exhibit diode characteristics. The diodes with Si nanocrystals produced the electroluminescence peak in the infrared range (0.9–1.0 eV), which spectral position was dependent on the laser annealing conditions. It was suggested that radiative transitions are related to the nanocrystal/amorphous silicon matrix interface states. The proposed approach can be used for producing of solar cells or light-emitting diodes on non-refractory substrates.

In this paper, the influence of the conditions of chemical and electrochemical nickel plating of nanostructured silicon and subsequent heat treatment on the phase composition of Si/Ni structures with advanced interface is studied. Nanostructured silicon formed by chemical and electrochemical etching was used for the formation of a developed interphase surface. The resulting Si/Ni samples were analyzed using scanning electron microscopy, energy dispersive X-ray analysis, and X-ray phase analysis. The experiments have revealed the differences in phase composition of the Si/Ni structures obtained by different methods, both before and after heat treatment.

Influence of the alkalis (KOH, NaOH), acids (HNO₃, HCl, H₃PO₄, H₂SO₄) and solvents (C₃H₇NO, deionized water) on the Ge₂Sb₂Te₅ thin films was investigated. Most possible etching mechanism of GST225 thin films by HNO₃ solution was proposed.

There are two ways to solve the glass-formation prognosis problem in the absence of a unified concept of glass-formation that connects its structural-chemical, kinetic, and thermodynamic aspects. Structural-chemical and energetic factors of glass-formation, together with the relaxation conditions of glass- forming ability with increase in atomic numbers of elements have been considered as a starting point for the development of the structural-energetic concept of glass formation.

Study of new materials and composites based on porous silicon is of great interest for electronics and microelectronics industry. Functional characteristics of structured layers are closely associated with their morphology properties and treatment conditions correspondently. In this work a porous silicon layers formed by metal-assisted chemical etching (MACE) with the use of gas adsorption-desorption method, scanning electron microscopy (SEM) and fractal geometry have been examined. Specific surface area given by multi-point BET method was about of 7 m₂/g and 13 m₂/g for n-Si and p-Si specimens correspondently. Surface fractal dimension D_s was estimated for p-type mesoporous silicon from BET results using Neimark’s thermodynamic approach, the value is D_s=2.86. “Slit islands” Mandelbrot’s algorithm was applied for analysis of SEM images and calculations of surface fractal dimension D_s, computation gives D_s = 2.52 for n-Si sample and D_s = 2.84 for p-Si sample. The study testified the fractal nature of porous layers formed by MACE and exhibits correlation between different methods of fractal dimension estimation. The results can be applied for improvement of methods of structured solids characterization.

The experimental results relating to exciting the defect–impurity subsystem of a (001)-oriented Si substrate containing ion-synthesized buried Si:P:O layer and transformation of the material into a porous medium are represented. After coimplantation with P⁺ and O₂⁺ ions, the substrates are subjected to the annealing in non-isothermal reactor at two average temperatures (900 and 1100°C, 5 min) and two opposite directions of an axial temperature gradient grad T. The temperature difference between reversed sides of the substrate is estimated of the order of ~ 1.5 and ~ 3 °C, respectively. After further thermal evolution in conventional furnace (1150 °C, 4 hours) and cleaving, the formation of two types of a porous structure in the specimens is exposed. The first type of this structure is the developed porous structure, where initially spheroid-like empty voids have grown up in size and changed their shape to form octahedron construction. The second type of this structure is a regular array of hollow tubes oriented along screw components of misfit dislocations. In the both cases, the porous structures always are initiated on the substrates, whose implanted sides have been faced to the cold pedestal during annealing in non-isothermal reactor.

Applicability of porous anodic alumina formed in selenic acid based electrolyte as the matrix for formation and Raman characterization of nanomaterials is investigated. For that, Raman spectra of nanostructured CdS layers deposited on top of porous alumina matrices are obtained. These spectra were compared with the ones, registered for the composites prepared using the commonly used matrix formed in oxalic acid solution. It is shown that application of porous alumina matrix formed in selenic acid electrolyte afford to detect the peaks corresponding to the CdS layers even at small amounts of CdS. It happens due to the absence of luminescence background in such matrix, which exists in matrices produced in organic acid electrolytes, for example, in oxalic acid.

Nanocarbon materials are of great interest as field emission cathodes due to their low threshold voltage. In this work current-voltage characteristics of nanocarbon electrodes were studied. Low-threshold emission was found in planar samples where field enhancement is negligible (<10). Electron work function values, calculated by Fowler-Nordheim theory, are anomalous low (<1 eV) and come into collision with directly measured work function values in fabricated planar samples (4.1-4.4 eV). Non-applicability of Fowler-Nordheim theory for the nanocarbon materials was confirmed. The reasons of low-threshold emission in nanocarbon materials are discussed.

This work is devoted to the CVD-synthesis of arrays of carbon nanotubes (CNTs) on Co-Zr-N-(O), Ni-Nb-N-(O), Co- Ta-N-(O) catalytic alloy films from gas mixture of C₂H₂+NH₃+Ar at a substrate temperature of about 550°C.Heating of the amorphous alloy causes its crystallization and squeezing of the catalytic metal onto the surface. As a result, small catalyst particles are formed on the surface. The CNT growth takes place after wards on these particles. It should be noted that the growth of CNT arrays on these alloys is insensitive to the thickness of alloy film, which makes this approach technically attractive. In particular, the possibility of local CNT growth at the ends of the Co-Ta-N-(O) film and three-level CNT growth at the end of more complex structure SiO₂/Ni-Nb-N-O/SiO₂/Ni-Nb-N-O/SiO₂/Ni-Nb-N-O/SiO₂ is demonstrated.

Low-dimensional transit-time structures for terahertz generation and detection are discussed. The negative conductivity at terahertz frequencies is crucial for generation. It may arise in an array of silicon nanowires (1D), as well as in a thin silicon layer (2D) in “silicon-on-insulator” wafer. Ballistic regime, scattering regime and alternating barrier injection regime (BARITT) are simulated. The latter allows a negative conductivity even for rather strong scattering.

The characteristics of high performance signal detection over a wide frequency range (1 MHz ÷ 100 GHz) in the context of a non-standard application for tunnel diodes is discusses.

The periodical-in-voltage features of the negative differential conductance (NDC) region in the current-voltage characteristics of a high-quality GaAs/AlAs terahertz resonant-tunneling diode have been detected. The found oscillations are considered taking account of the LO-phonon excitation stimulated by tunneling of electrons through the quantum active region in the resonance nanostructure where an undoped quantum well layer is sandwiched between two undoped barrier layers. Rearrangements in the I-V characteristics of the resonant-tunneling diode as a consequence of the topological transformation of a measurement circuit from the circuit with the series resistance R_s to the circuit with the shunt R_p have been experimentally studied and analyzed. The revealed substantial changes in the current-voltage characteristics of the resonant-tunneling diode are discussed schematically using Kirchhoff's voltage law.

We have developed the ultra-short pulsed laser processing methods for patterning of graphene field effect transistors in topological and chemical way. We investigated in details the photoresponse in graphene FETs before and after laser-induced modification for laser influence below threshold energy. We observed two different mechanisms of the photoresponse under ultra-short laser pulses (280 fs). The photocurrent, observed for both pristine and laser processed graphene is raised because the laser induced charge is transferred from graphene to trapped levels in SiO₂ surface resulting in electrostatic Dirac point shift. For laser oxidized areas we observed more pronounced photocurrent because of heterojunction formation in laser-processed area. While for electrostatic effect the relaxation time estimated as 50 seconds, the heterojunction relaxation was observed for less than 3 ms.

In this article, we have studied the influence of Si3N4 and SiO2 thin film gate dielectrics on the current-voltage characteristics of the graphene-based transistor. The test structure of graphene transistor was fabricated with the top and back gate. Graphene has been produced by chemical vapor deposition, and then transferred to the silicon dioxide on a silicon wafer. The channel of the transistor has been formed by etching in oxygen plasma through a photolithographic mask. Metals electrodes of the drain, source, and gate were deposited by resistive evaporation in a vacuum. It was used titanium / aluminum with a thickness of 50/200 nm. In the case of the back gate, silicon dioxide was used, obtained by thermal oxidation of the silicon substrate. For top gate was used silicon nitride deposited by plasma chemical deposition. It was demonstrated that field effect is more pronounced for the case of SiO2 back gate compare to the Si3N4 top gate. For the SiO2 back gate we have observed that the source- drain current decreases, from 2 mA to 3 mA, with increasing the gate voltage, from 0 to 40 V, at constant source-drain voltage, 2 V. In case of Si3N4 top gate the modulation of source-drain current was not significant for the comparable electric field strength. Based on the value of gate voltage for current minima in transfer function the poor quality of Si3N4 –graphene interface is concluded.

The gated GaAs structures like the field-effect transistor with the array of the Sn nanothreads was fabricated via delta-doping of vicinal GaAs surface by Sn atoms with a subsequent regrowth. That results in the formation of the chains of Sn atoms at the terrace edges. Two device models were developed. The quantum model accounts for the quantization of the electron energy spectrum in the self-consistent two-dimensional electric potential, herewith the electron density distribution in nanothread arrays for different gate voltages is calculated. The classical model ignores the quantization and electrons are distributed in space according to 3D density of states and Fermi-Dirac statistics. It turned out that qualitatively both models demonstrate similar behavior, nevertheless, the classical one is in better quantitative agreement with experimental data. Plausibly, the quantization could be ignored because Sn atoms are randomly placed along the thread axis. The terahertz hot-electron bolometers (HEBs) could be based on the structure under consideration.

The superconducting properties of ruthenium (Ru) thin films and microstructures are investigated. The microstructures are used as transition edge sensors (TES), working at He-3 evaporation cryostats’ temperatures. Ruthenium is substantially inert, and the critical temperature T_c for bulk Ru samples is known from state of art to be 0.40-0.51 K. We investigated magnetron sputtered Ru thin films with thicknesses 13-300 nm on a Si substrate and electron lithography fabricated TES samples, based on the thin-film Ru microstructures. It has been found, that the T_c for the Ru thin films is 0.55-0.70 K, and the width of the transition region is 1-5 mK, and for the Ru TES T_c = 0.55 and ΔT = 4 mK. Furthermore, it was established that lithography process had no significant influence on the properties of the TES samples, so we were able to get consistent properties for several fabrication sessions. Therefore ruthenium is concluded to be a desirable material for transition edge sensors working at He-3 cryostats’ temperatures.

The results of investigation of a memristor nanostructures based on titanium nanowires fabricated by methods of focused ion beams are presented. The memristor effect in the titanium nanowires is investigated by an AFM in the mode of spreading resistance map. It is shown that the using of FIB milling allows to form conductive channels with different shapes and nanoscale dimensions. The analysis of the I-Vs of Ti nanowire memristor structures shows that the resistivity ratio in the high- and low-resistance states is higher than 10². After a series of measurements determined that memristor structures have a high stability of resistance. The obtained results are most promising for developing the technological processes of the formation of resistive operation memory cells.

The resistive switching of vertically aligned carbon nanotube (VA CNT) by the action of a compressive strain is shown. The memory cell based on compressed VA CNT has been created. Origin of resistive switching of strained VA CNT is described. It is shown the resistive switching associated with redistribution of deformation and corresponding piezoelectric charge in the nanotube. The ration resistance of high-resistance to low-resistance states of the memory cell amounts 7 at voltage reading of 0.2 V. The results can be used in the development nanoelectronics devices based on VA CNTs, including the resistive random-access memory.

Graphene is a nanomaterial that due to unique properties has attracted great interest for various applications, in particular, for development of nanoelectronic devices. In the paper the graphene field-effect transistors (GFET) and resonant tunneling diodes (RTD) are analyzed with the use of proposed models.

First, simulation of dual-gate field-effect transistor based on monolayer graphene with the use of proposed combined model is considered. In the model the following important factors such as quantum capacitance, hole and electron mobility difference, drain and source resistances are taken into account. Investigations of dependence of a drain current on drain voltage for various top-gate-to-source voltages are performed. Influence of channel length, source and drain resistances on output characteristics of the device is analyzed. Comparison of calculation results with simulation ones obtained with the known models was carried out.

Secondly, simulation of graphene-based nanostructures on hexagonal boron nitride, silicon carbide and silicon dioxide substrates was performed using proposed self-consistent numerical model, based on effective wave function formalism. The developed models in detail were described in our previous works. The possibility of using a proposed self-consistent model for double- and triple-barrier graphene-based RTD simulation was illustrated. As well as it was investigated the influence of different parameters on IV-characteristics of graphene-based RTDs. It was shown that it is necessary to take into account extended (passive) regions for adequate simulation of these devices.

Ensemble Monte Carlo simulation of electron transport in GaAs/AlAs quantum wire transistor structure is performed. The response of electron drift velocity on the action of harmonic longitudinal electric field is calculated for several values of electric field strength amplitude and gate bias at 77 and 300 K. The periodical electric field has a 1 THz frequency. The nonlinear behaviour of electron drift velocity due to scattering processes is observed.

Paper presents the results of research of electrical characteristics features of multibarrier AlxGa1-xAs/GaAs heterostructures with tunnel-nontransparent potential barriers. Briefly described constructive-technological features fabricated using molecular beam epitaxy. We measured the quasi-static current-voltage characteristics of test items by electric pulses of duration 10-6 s and a duty cycle of 103. Observed characteristics with a strong section of the negative differential resistance in the current range of several tens of milliampers. It is proposed to use this effect for the generation of terahertz electromagnetic radiation. Briefly stated the theoretical interpretation of the observed phenomena on the basis of quasi-hydrodynamic theory of electron drift.

The simulation of current-voltage characteristics for 4H-SiC Schottky diode with Ti Schottky contact has been carried out with used of TCAD program. Obtained current-voltage characteristics has been analyzed and compared with theoretical and experimental results. It is established that the Schottky diode parameters (forward current, ideality coefficient, Schottky barrier height, breakdown voltage) obtained in proposed model are good agreement with data for such type diodes.

In this paper, we consider the issue of research and development of on-chip optoelectronic devices designed for the optical interconnecting of integrated circuit elements. We address the conceptual on-chip optical interconnections based on A^IIIB^V nanoheterostructure lasers with functionally integrated modulators of optical radiation. According to the estimations, these optoelectronic devices can generate subpicosecond optical pulses. The paper is aimed at the development of numerical models, simulation methods, and specialized software. These aids are intended for the research of physical processes taking place in high-speed heterostructure photodetectors suitable for operation as parts of on-chip optical interconnections together with the lasers-modulators. We propose to utilize the drift-diffusion approximation of the semiclassical approach for the numerical simulation of charge carrier transport and accumulation in semiconductor photosensitive heterostructures. The drift-diffusion numerical simulation technique was developed. This technique is based on the application of the Newton method, implicit difference scheme, and Slotboom drift-diffusion formulation in terms of electron and hole imref exponents and electrostatic potential. We researched p+-Al_0.3Ga_0.7As/i-GaAs/n+-Al_0.3Ga_0.7As and metal/n-Al_0.3Ga_0.7As/n+-GaAs heterostructures. Rise and fall times of the devices being considered are approximately equal and amount to about 1.6 ps for the p-i-n structure and 1.7 ps for the Schottky-barrier photodiode. We concluded that it is reasonable to develop the methods directed at the improvement of photodetector response speed.

In this article the layout and structure of the microwave switcher based on the managed electron density maximum rearrangement in multi-contacts functionally integrated active region are considered. The basis of the microwave switcher is a normally opened high electron mobility transistor structure (HEMT) with multiple Schottky gates and the corresponding number of switching ohmic contacts. In this research two-dimensional finite-difference physical and topological model of the considered microwave switchers is proposed. The distinctive features of the proposed model are combination of two different sets of variables and explicit first-order upwind discretization scheme for the normalized continuity equation. The obtained results of numerical modeling are discussed.

This paper considers the possibility of constructing nonreactive memristor-based oscillators adding a device exhibiting negative differential resistance (NDR). The ambipolarity of the memristor I-V characteristic is shown to ensure the generation mode of such circuits. S-type and N-type variants of the memristor-based oscillator are analyzed. Device and circuit implementations of ambipolar memristors are suggested. NDR devices, as well as single-threshold comparators can be used in the implementation of ambipolar memristor-based oscillators.

An operator of the permittivity can completely describe alone a microwave response of conductors with the spatial dispersion. An eigenvalue problem for the nonself-adjoint permittivity operator Ễ_a was considered generally to search the wave solutions for conductors and superconductors. An appearance of additional solutions (additional waves) due to the spatial dispersion can strongly influence the properties of nanoelectronic devices or novel superconducting materials in the form of anomalous losses for example, and should be accounted in simulation and modeling of micro- and nanoelectronic devices. It was concluded that the modulus |Ž| of the surface impedance is proportional to the degree of frequency ω^2/3 for all normal conductor solutions except that for the superconductor. There was some criticism related to the idea that the electrodynamics of superconductors should be in principle reduced to those for conductors as the temperature approaches and beyond the critical temperature. We demonstrate that appropriately taken into account effects of the spatial dispersion can give the general frequency dependence of the surface impedance for the obtained solutions including that for the superconductor. It is shown that an incorporation of the spatial dispersion leads to an appearance of the Meissner effect in perfect conductors in the same manner as in superconductors.

The task about calculation of high-frequency conductivity and Hall constant of a thin semiconductor film is solved by the kinetic method. This film is placed in transverse stationary magnetic field and longitudinal alternative electric field. The ratio between film thickness and mean free path of charge carriers is assumed to be arbitrary. Skin effect is negligible. The diffuse-specular mechanism of charge carriers scattering from film surfaces is considered in the view of equal mirrority coefficients of the upper and lower film surfaces. The dependences of non-dimensional conductivity and Hall constant on non-dimensional parameters: electric field frequency, magnetic field induction and film thickness are investigated. The comparative analysis of obtained results with the calculations for the case of a metal film are made.

In this paper based on the new parameterization shape, an alternative heavy ion induced soft errors characterization approach is proposed and validated. The method provides an unambiguous calculation procedure to predict an upset rate in highly-scaled memory in a space environment.

A compact MOSFET model is described, which is adapted to simulate the drain current under irradiation.

We propose a Verilog-A modeling concept for modern bulk and SOI FinFETs TID sensitivity modeling. The concept allows to model the fin width and length dependencies of TID sensitivity.

We present a reasonable application of triple modular redundancy as an effective method of multiple soft error mitigation in 65-28 nm CMOS VLSI.

Single Event Transient (SET) caused by charged particle traveling through the sensitive volume of integral circuit (IC) may lead to different errors in digital circuits in some cases. In technologies below 180 nm, a single particle can affect multiple devices causing multiple SET. This fact adds the complexity to fault tolerant devices design, because the schematic design techniques become useless without their layout consideration. The most common layout mitigation technique is a spatial separation of sensitive nodes of hardened circuits. Spatial separation decreases the circuit performance and increases power consumption. Spacing should thus be reasonable and its scaling follows the device dimensions’ scaling trend. This paper presents the development of the SET simulation approach comprised of SPICE simulation with “double exponent” current source as SET model. The technique uses layout in GDSII format to locate nearby devices that can be affected by a single particle and that can share the generated charge. The developed software tool automatizes multiple simulations and gathers the produced data to present it as the sensitivity map. The examples of conducted simulations of fault tolerant cells and their sensitivity maps are presented in this paper.

Application variety and huge potential market of RF MEMS switches guarantee relentless research interest to the field. There are lots of different types of MEMS switches. Direct contact MEMS switches are simplifier for integration than capacitive MEMS switches. Lateral technology considerably simplifies the formation process. The objective of this research is to estimate characteristics of the simple direct-contact lateral MEMS switch and to understand the improvement directions.

The MEMS switches were fabricated on the SOI wafers by e-beam lithography, dry etching and wet HF-etching. E-beam lithography and dry etching were used to form the cantilever and electrodes on the buried oxide layer. The structure with two control electrodes was used. IV characteristics were measured by Keithley 4200-SCS. The distance between cantilever and control electrodes was 100 nm.

From the obtained IV characteristics it is clear that the devices switches at about 60 V. High control voltage could be explained by the large distance between cantilever and control electrode, and high rigidity of the cantilever.

Following simulation in COMSOL Multiphysics showed that the control voltage could be decreased to 20-30 V by adding of spring element to the cantilever and device geometry modification.

Electrostatically actuated MEMS switch with the resistive contact is presented. Design of the switch includes the active contact breaking mechanism, which allows to detach the beam from the signal electrode in case of sticking. The mechanism is realized by the presence of two driving electrodes under the beam. The switch is fabricated by the surface micromachining. Finite element simulation and experimental investigation of the switch in a cold regime are performed.

In the report the linear acceleration sensor design with three axis of sensitivity is researched. Parameterized geometry and finite element model for modal analysis are developed in the ANSYS program. Behavioral description of the study design is developed with language VHDL-AMS to simulate the sensor operation under the influence of linear acceleration along three axis of sensitivity. On the basis of research results three-axis device sensitivity, cross-sensitivity, duration transients are specified. As part of the work the experimental sensor prototypes are fabricated.

The paper presents computer simulation results of heavy charged particles radiation effect on elements of electrostatic microelectromechanical systems. Modeling methods of heavy charged particles impact on MEMS elements were envisaged. The radiation sensitivity of different types of fractal electrostatic MEMS were evaluated. Methods of reduction of radiation impact on electrostatic MEMS based on fractal theory were discussed. Conclusions about fractal electrostatic MEMS features were outlined.

This paper presents the new architecture of 2-DOF (degree-of-freedom) drive mode and 1-DOF sense mode gyroscope with the concept of additional anchoring that retains all the advantages of the Dynamic Vibration Absorber (DVA) concept while being operated at high frequencies. These concepts allow reduction of the bandwidth by varying the coupling parameter during the design, thereby increasing the mechanical sensitivity. In the present design, the anchoring concept has been implemented by adding a central anchor for the sense mass. The steady state response and design concept have been devised using analytical modeling.

A method of signal processing devices design for micromechanical accelerometers with capacitive transducers is proposed. This method provides the complex solution of the sensibility increasing and noise immunity problems by finding of the difference frequency of signals, which are formed by two identical generators with micromechanical capacitive transducers in frequency control circuits. In this study the analog and digital versions of the highly sensitive signal processing devices circuits with frequency output were developed. The breadboards of these devices are fabricated and studied and the project of their integral realization is designed.

A method based on electrophoretic deposition (EPD) has been developed to produce uniform and local deposits of multiwalled carbon nanotubes (CNT) on interdigital structures of planar supercapacitor (SC) at room temperatures. Alcohol/acetone suspensions were used under constant voltage conditions in the range of 6 to 100 V, with deposition times ranging from 2 to 60 minutes and electrodes space from 2 to 15 mm. It was shown that for dense layers deposition with good adhesion on the narrow lines of the planar SC electrodes it is necessary to use average values of the electric field and multi-stage method in which the deposition and drying processes are alternated. Electrochemical tests of the sandwich-like supercapacitors with electrodes obtained by the described method were carried out. The specific capacity of experimental samples increased from 0.24 to 1.07 mF/cm2 with an increase in the number of EPD cycles from 3 to 9.

We developed a new platform for biosensing applications. Aptamers as sensitive agents have a great potential and gives us possibility to have highest possible selectivity among other sensing agents like enzymes or antibodies. We covalently bound aptamers to the functional groups of c-CNTs and then put this system on the surface of polymer substrate. Thus we got high sensitive flexible transparent biological sensors. We also suggest that by varying aptamer type we can make set of biosensors for disease detection which can be integrated into self-healthcare systems and gadgets.

This paper describes using a MET-based low-noise angular motion sensor to precisely determine azimuth direction in a dynamic-scheme method of measuring Earth’s rotation velocity vector. The scheme includes installing a sensor on a rotating platform so that it could scan a space and seek for the position of highest Earth’s rotation vector projection on its axis. This method is very efficient provided a low-noise sensor is used. We take a low-cost angular sensor based on MET (molecular electronic transduction) technology. Sensors of this kind were originally developed for the seismic activity monitoring and are well-known for very good noise performance and high sensitivity. This approach, combined with use of special signal processing algorithms, allowed for reaching the accuracy of 0.07° for a measurement time of 200 seconds.

Planar electrochemical systems are very perspective to build modern motion and pressure sensors. Planar microelectronic technology is successfully used for electrochemical transducer of motion parameters. These systems are characterized by an exceptionally high sensitivity towards mechanic exposure due to high rate of conversion of the mechanic signal to electric current. In this work, we have developed a mathematical model of this planar electrochemical system, which detects the mechanical signals. We simulate the processes of mass and charge transfer in planar electrochemical transducer and calculated its transfer function with different geometrical parameters of the system.