Volume 54, Nº 2 (2025)

Sensitivity control of semiconductors often requires changing their crystal and electronic structure, which can lead to the loss of their initial semiconductor properties. Chalcogenide semiconductors have high carrier transport properties. However, they face limitations in detecting hard X-rays due to various reasons, in particular, their defective structure and poor X-ray sensitivity. The basic laws of the theory of X-ray conductivity of semiconductors are generalized and simplified taking into account their areas of application. The features of the influence of doping on X-ray sensitivity, determination of the optimal concentration of the dopant, using the example of Cr-doping of chalcogenides, as well as the principle of creating an X-ray detector are considered. As an example of an important X-ray sensitive material, our results on the study of photo- and X-ray conductivity in the layered compound with a monoclinic p-type structure TlGaS₂ containing a doped chromium impurity are presented. Our experimental results of the study of synthesized and grown single crystals of chromium-doped (≤ 0.5 mol. % Cr) TlGaS₂:Cr are presented. It is shown that TlGaS₂:Cr-based materials retain semiconductor properties and are characterized by high electrical transport. Chromium doping increases photosensitivity and polarization between metal and chalcogenide ions in TlGaS₂:Cr. The doping of Cr impurity on the photoconductivity and band gap of the layered TlGaS₂ single crystal was studied. The change in the spectral sensitivity region of TlGaS₂:Cr and the appearance of impurity photocurrent peaks in the photon energy region were analyzed. The X-ray dosimetric properties of TlGaS₂:Cr were studied depending on the irradiation doses. Using TlGa_0.995Cr_0.005S₂ as an example, it was shown that the volt-dose characteristics have good reproducibility. The single crystal detector sample TlGa_0.995Cr_0.005S₂ also demonstrated high photo- and X-ray sensitivity compared to pure TlGaS₂. The obtained new photoelectric and X-ray dosimetric properties and results show the potential of TlGaS₂:Cr semiconductor for optoelectronic and radiation technologies.

Using oxidized lead selenide as the interface, Ag/PbSeO_x/PbSe heterostructures were made, demonstrating stable memristive characteristics. In order to obtain metastable multilevel states on such structures, studies have been performed using different protocols for delivering pulsed signals. By adjusting the number, amplitude, duration, and fill factor of the pulses, 13 metastable resistive states were implemented. The memristor under study showed good stability and reproducibility for several months.

As the IC scales, it becomes necessary to form lines with a width of less than 20 nm at the lower levels of the metallization system. Copper at such sizes ceases to meet the requirements for RC delays and resistance to electromigration. Therefore, it is necessary to look for alternative materials to replace copper, which will provide higher resistance to electromigration and lower resistance of the lines. The most promising candidate is Ru. In this study, test structures with ruthenium lines were obtained. For this purpose, such methods of creating structures as plasma-stimulated deposition from the gas phase, plasma-stimulated atomic layer deposition, magnetron sputtering, electron beam lithography, and plasma chemical etching were used. Spectroscopic ellipsometry and scanning electron microscopy were used to control the creation and investigation of the resulting structures. The electrical characteristics of the structures were measured and tested.

The influence of various sources of variability on transistor performance increases with the transition to three-dimensional architectures, and the roughness boundary of the transistor's working area is one of the main factors contributing to this increase. In this paper, the variability of the key parameters of silicon field-effect GAA nanotransistors with an unalloyed cylindrical working area with different working area lengths from 25 to 10 nm is investigated to demonstrate the effect of scaling. Fluctuations in the characteristics are analyzed for two values of correlation lengths of 10 nm and 20 nm and a range of RMS values of boundary deviations in the range from 0.4 to 0.85 nm. For the key parameters under study, threshold voltage, Ion and Ioff currents, the standard deviation values for transistor structures with different channel lengths differ by about 2 times. At the same time, the patterns of variability of key parameters are functionally different. The consequence of this is that the methods for optimizing the effect of variability are not scalable due to the effect of boundary roughness.

Applications related to the use of artificial intelligence (AI) and the Internet of Things require high-performance computing systems. Modern digital neuromorphic coprocessors, which are manufactured using CMOS technology, are ineffective in executing neural network algorithms due to the limitations of the von Neumann architecture. A promising direction for research in this area is integrated circuits based on non-volatile ferroelectric transistors. The paper provides an overview of studies devoted to ferroelectric materials, characteristics of ferroelectric transistors and methods for their study.

Experimentally obtained precision technology of forming a controlled profile of aluminum conductive paths with a specified resistance is presented. The technology is based on anisotropic plasma-chemical etching of aluminum in the gas mixture BCl₃ – Cl₂ with subsequent precision adjustment of path resistance by the “dry” plasma-chemical method. It is shown that in order to ensure the highest quality plasma chemical etching of aluminum with minimal under etching under the photoresist mask, with minimal inclination of the aluminum conductive path profile and absence of defectiveness of the etching pattern and stratified areas, it is necessary to use a multistage iterative technological process with technological operations of surface preparation before etching and operations of polymer and photoresist removal after etching.