The developed technologies of CMOS structures and nonvolatile memory based on them will encounter the fundamental limits already in 2018-2020. Currently, an intensive research is being executed for obtaining the new devices based on new physical principles, which, potentially, will have more scaling possibilities. As such devices the memresistors have been proposed to be used. A review of up-to-date literature, devoted to recent developments in the area of creating the memresistor structures, as well as the arrays based on them, has been presented. The materials, manufacture technologies and physical principles of the memresistor structures functioning, as well as current technologies of creating the arrays of these structures have been in detail considered. The most perspective fields in development of the memresistors based on chalcogenides, metal oxides, fast ion conductors have been presented.
The peculiarities in kinetics of the local probe oxidation of ultra thin V, Nb, Ta, Ti, TiN, TiN, W metal films have been investigated. It has been found that the process kinetics is determined by such properties of the material being oxidized, as the specific resistance, presence of the surface natural oxide film and its thickness, the correlation of specific density of metal and oxide, the oxidation process electric-chemical constant. As a material, providing the maximum productivity in formation of the local dielectric regions, having nanometer dimensions, vanadium has been chosen, that is characterized by maximum rate of the anodic probe oxidation.
For creating DRAM and flash-memory alternative of existing element base there are the memristive structures, based on resistance switching. In the paper the results of the study of formation features of creating the memristive structures based on copper sulfide as one of the promising materials, providing an increased efficiency of the structures, have been presented. Using a scanning electron microscope the process of the copper sulfurization in the «chemical bath», in which the near-surface region of the copper layer was transformed to sulfurization and the rest part of the layer was used as an active electrode of the formed further memristive structure, has been considered. It has been shown that with increased concentrations of the initial chemical reagents the roughness of the sulfide layer surface significantly increases. The sulfide growth speed with optimal initial concentrations of the chemical reagents is ~ 30 nm/min. In the investigation of the memristive structures it has been found that with increasing the copper sulfide thickness the resistance ratio in the low-resistance and high-resistance states grows from 11.2 to 12.5. The switching time in the formed memristor structures from the high-resistance state to the low-resistance one is about 1.3 µs, and from the low-resistance to high-resistance state it is 0.9 µs.
Nowadays, one of the priority directions of development of electronics both in our country and abroad is the creation of silicon semiconductor devices and IC with the submicron topological dimensions capable of functioning at temperature 200 °C and higher. Metallization is a critical node of the silicon electronic component base from the point of view of thermal stability. Recently, as an interconnection material tungsten, which has higher electromigration resistance compared with aluminum (with silicon and copper additives) is used. In the work the results of the technological regimes research of W(Ti-15 %) alloy films magnetron sputtering have been presented. During investigating the mechanical properties of the films it has been determined that the structure W(Ti-15 %)-Si is characterized by a lower level of mechanical stresses in lateral direction compared to the built-in mechanical stresses in the W-Si structure. It has been revealed that the full force of the film of tungsten with titanium alloy approximately three times exceeds that one of the tungsten film. It has been shown that the metallization based on tungsten alloyed with titanium is characterized by a significantly higher elctromigration resistance compared to metallization based on an alloy of aluminum with copper and silicon. The results based on a comparative analysis of the electric-physical and mechanical characteristics of sputtered on silicon tungsten films and the alloy of tungsten with titanium from the point of view of using them as interconnections in heat-resistant silicon IC have confirmed their promising implementation.
The results of studies on the film composites, based on polyvinylidene fluoride with the carbon nanotubes, by the dielectric relaxation spectroscopy have been presented. For the composite samples with the content of nanotubes exceeding 0.5 wt% the nonlinear current-voltage characteristics have been obtained. The concentration dependences of conductivity of the composites have been studied and, also, the percolation threshold for the samples being investigated has been determined. It has been shown that an insignificant increase of the composites electric conductivity is observed even at 0.2 wt%, while introducing 1 wt% of nanotubes the electrical conductivity becomes 3 orders higher and at more than 3 wt% it is 7 orders higher compared to the non-filled polymer. This verifies the perspectives of using the carbon nanotubes for creation of the electro-conducting composites and film materials based on polyvinylidene fluoride.
The thermomagnetic recording on thin films is currently one of the most perspective methods for copying records with high density and weak residual magnetization, for example, in forensics. The technology of thermomagnetic recording is in demand to increase the information recording density of up to 10 Tbit per 1 squre inch. An intensive search for the most effective materials to create the carriers of thermomagnetic recording is being performed. The results of studying the domain structure of the high-coercive ferrite-garnet films, synthesized by liquid-phase epitaxy with low Curie temperature as the carriers of thermomagnetic recording, have been presented. The domain structure of the PC floppy disk has been copied onto the ferrite-garnet film and has been studied by method of the magnetic force microscopy. It has been shown that the resolution for thermomagnetic recording on the ferrite-garnet film is limited by a network of defects in the crystal, by the structure and morphology of the surface, connected with it, and by the mismatch parameters of the substrate-film lattices. The obtained results demonstrate that the high-coercive ferrite-garnet films with low Curie temperature can be applied as the carriers of thermomagnetic recording.
The method of three-through passage measurements in magnetic force microscopy has been described. It provides to obtain real magnetic images of nano- and micro-objects, excluding possible parasitic action in producing a magnetic image of the long-range electrostatic forces.
The results of the studies on the scanning electrical-conductivity Transport Properties have been shown. The correlation of the required pressing force on the conductive cantilever to the surface, which provides a close contact with the test sample, with the material hardness and the thickness of the cantilever conductive coating, has been revealed. It has been shown that while investigating at higher values the potential difference on one hand, it is necessary to take into account the possible effect of the conductive coating material redistribution from the cantilever to the sample surface, on the other hand- the ability to provide the higher resolution while investigating the sample topography by conductive cantilever.
The results of the study on the influence of the seed copper layer surface state on the uniformity of the electrochemical copper fill of the grooves with submicron dimensions have been presented. It has been noted that the quality of the filling is connected with the absence or presence on the surface of the seed layer of the copper oxide film, characterized by the hydrophobic properties. It has been shown that for a uniform filling of the grooves with copper in the transition windows in the interlevel dielectric layers while creating the copper multilevel metallization of silicon ICs the time of the plates interoperational storage after deposition of the copper seed layer to fill the grooves with copper should not exceed the maximum allowable time ~ 6 hours.
The data on the peculiarities in formation on the surface of solid bodies of the dielectric mask, modulated by thickness, based on local anodic oxidation, have been presented. This has been achieved due to procedure of changing the voltage impulse parameters in the course of scanning according to the specified pattern of super-thin oxidized metal film. It has been shown that the process expands the capabilities of the local anodic oxidation for nanotechnologies in the functional electronics.