Valentina E. Kotomina

Computing in memory represented by resistive switching (memristive) devices is a promising way to implement hardware for artificial neural networks. We see it as the way to create energy-efficient and high-performance systems for solving a wide range of tasks in artificial intelligence. Here, we present the structure and performance of our crossbar array based on Au/Ta/ZrO₂(Y)/Pt/Ti memristive devices, integrated into a complementary metal–oxide–semiconductor fabrication process, and then demonstrate its applicability for the hardware implementation of artificial neural networks. The array contains 256 memristive devices combined into 32 columns and eight rows. Each memristive device is paired with an n-channel metal–oxide–semiconductor transistor. As the results of the simulations show, these devices enable running neural network algorithms for solving recognition problems using the Modified National Institute of Standards and Technology dataset with 98% accuracy and the Canadian Institute for Advanced Research (10 classes) dataset with at least 77.5% accuracy, even taking into account the errors of mapping weights onto the memristive crossbar. Fully hardware recognition of 4 bit images demonstrated in this work highlights the crucial role of selective transistors for such tasks. This paper explores the exciting potential of memristor-based components of neuroelectronics as the building blocks for a new era of artificial intelligence hardware, capable of surpassing current computational limitations, as well as their role in the ongoing transition to hybrid intelligence based on the symbiosis of electronic and biological systems.

The development of vacuum electronics is strongly correlated to advances in manufacturing technologies. The complexity of many modern prototypes of vacuum electron devices does not allow or greatly complicates their realization, and many ideas still remain theoretical. Modern 3D printing technologies can partially solve this problem, since, in comparison with modern CNC machines, they have great capabilities in accuracy, productivity and cost. However, this only applies to dielectric products, since metal 3D printers are currently significantly inferior to CNC machines in all respects. Therefore, special methods are required to realize metal products. In this paper, we propose a method for multistage chemical metallization of photopolymer structures (CMPS) printed using stereolithography technologies. Experimental testing of various elements of vacuum devices manufactured using this technology demonstrates great prospects for this approach.

The kinetics of diffusion processes occurring during the formation of polycrystalline Si_1-xGe_x nanostructures (x=0.20, 0.35) by spark plasma sintering in the temperature range 20-1200^oC was studied for the first time. A mechanism for the formation of a SiGe solid solution is proposed as a result of a comprehensive study of the microstructure and phase composition of samples with particle sizes from 150 nm to 100 μm, together with the analysis of experimental sintering maps. It is based on the phenomenon of mutual diffusion of Si and Ge atoms that occurs during the entire sintering process. For the selected sintering modes, the grain size of the formed SiGe corresponds to the size of the initial powder particles. Keywords: spark plasma sintering, solid solution SiGe, thermoelectric characteristics, figure of merit ZT.

The effect of sulfide passivation (chemical treatment in a peroxide-sulfur etchant and in a solution of Na₂S in isopropanol) and complication of the profile of the lateral surface of thyristor mesastructures on the blocking ability of GaAs thyristor mesastructures is investigated. It is shown that the blocking voltage of the chips increases several times both after chemical treatment of the surface and with the complication of the surface topology. Keywords: thyristors, blocking voltage, sulfide passivation, gallium arsenide, mesastructure.

The effect of sulfide passivation (chemical treatment in a peroxide-sulfur etchant and in a solution of Na2S in isopropanol) and complication of the profile of the lateral surface of thyristor mesastructures on the blocking ability of GaAs thyristor mesastructures is investigated. It is shown that the blocking voltage of the chips increases several times both after chemical treatment of the surface and with the complication of the surface topology.

Формирование мелкодисперсного термоэлектрика Si 1-x Ge x при электроимпульсном плазменном спекании

It is shown that two modes of resistive switching – bipolar and volatile unipolar – are peculiar for the Ag/Ge/Si structures with germinating dislocations in the germanium layer. In this modes the structures have stable states of electric current with ION/IOFF ~1.5–2.7. The volatile unipolar type of switching can be caused by the capture of charge carriers to deep levels associated with lattice defects in the Ge film of the memristor. At the same time, bipolar switching is associated with the drift of Ag+ ions along germinating dislocations.