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Modern semiconductor devices and microchips are sensitive to the effects of ionizing radiation. Nevertheless, they are widely used in military and space technology, in the nuclear industry. At the same time, a number of technological, circuit and software solutions are used to reduce the effects of radiation exposure. The most preferable method is one based on using shields, due to its low cost and excellent radiation properties of shield's materials. Recently, special attention has been paid to the study of multilayer structures. Experimental samples of Ni-Fe alloys and multilayer Ni-Fe/Cu structures with different chemical composition were obtained by electrochemical deposition. The dependence of chemical composition variation from deposition conditions was determined. Ni-Fe alloys crystal structure was studied using X-ray diffraction. Shielding properties of Ni-Fe/Cu multilayer structures were investigating on linear accelerator ELA-4 under 4 MeV electron irradiation. Silicon p-MOSFETs were used as test structures. Evaluation of electron flow weakening effectiveness was performed by current-voltage characteristics changing – threshold voltage of pMOS-transistors, which were located behind shields based on NiFe/Cu multilayered structures and without shields. It was found that increasing number of Ni-Fe layers within the same total thickness leads to maximum shielding efficiency. ; Современные полупроводниковые приборы и микросхемы чувствительны к воздействию ионизирующих излучений. Тем не менее они широко применяются в военной и космической технике, в ядерной индустрии. При этом используется ряд технологических, схемотехнических и программных решений, уменьшающих последствия радиационного воздействия. Наиболее предпочтительным решением является выбор метода на основе использования экранов, поскольку он экономичнее и определяется радиационными свойствами используемых для изготовления экранов материалов. В последнее время особое внимание уделяется исследованию многослойных структур, так как при прохождении излучений через эти материалы возможно значительное ослабление эффектов радиационного воздействия, что имеет значительный научный и прикладной интерес. Методом электролитического осаждения получены экспериментальные образцы покрытий сплавов NiFe и многослойных структур NiFe/Cu с различным химическим составом. Установлены зависимости изменения химического состава от условий осаждения. Методом рентгеновской дифракции проведены исследования кристаллической структуры. Покрытия характеризуются гранецентрированной кубической решеткой, с увеличением концентрации железа параметр элементарной ячейки увеличивается. Эффективность радиационной защиты многослойных структур NiFe/Cu оценивалась при облучении электронами с энергией 4 МэВ на линейном ускорителе ЭЛУ-4. В качестве тестовых структур использовались кремниевые МОП-транзисторы. Эффективность ослабления электронного потока была оценена по изменению вольтамперных характеристик: порогового напряжения для МОП транзисторов, расположенных за экранами на основе многослойных структур NiFe/Cu, и без экранов. Установлено, что с ростом количества слоев при сохранении суммарной толщины эффективность экранирования увеличивается, что позволяет создавать высокоэффективные экраны при сопоставимых массогабаритных параметрах.

For decreasing the radiation effects of the cosmic environment on the electronic components of spacecraft, local protection shields are used. They are manufactured on the basis of materials with high density and large atomic numbers (tungsten, tantalum, the W-Cu composite etc.) and then integrated into the ceramic-and-metal package of electronic components with an insufficient level of radiation resistance. On the basis of the Monte Carlo approach we considered the methods of decreasing the level of the dose absorbed by the crystals of active elements if using the radiation shields based on the W-Cu composite in hybrid metal cases under the action of electrons of a circular orbit with an inclination angle of 30° and an altitude of 8000 km. The electron spectra at the maximum and minimum solar activity were obtained using OMERE 5.3 software. It was established that an increase in the mass thickness of the base and cover of cases with shields up to 1.67 g / cm2 makes it possible to reduce the dose load by 3.5–3.7 times at the minimum and by 3.9–4.1 times at the maximum of solar activity. The optimization of protection by lowering the upper layer of the W-Cu composite to the base to a height of 1.2 mm reduces the absorbed dose by 6.8–9.3 times at the minimum and by 7.6–10.7 times at the maximum solar activity.

The effect of microstructure on the efficiency of shielding or shunting of the magnetic flux by permalloy shields was investigated in the present work. For this purpose, the FeNi shielding coatings with different grain structures were obtained using stationary and pulsed electrodeposi-tion. The coatings' composition, crystal structure, surface microstructure, magnetic domain struc-ture, and shielding efficiency were studied. It has been shown that coatings with 0.2–0.6 µm grains have a disordered domain structure. Consequently, a higher value of the shielding efficiency was achieved, but the working range was too limited. The reason for this is probably the hindered movement of the domain boundaries. Samples with nanosized grains have an ordered two-domain magnetic structure with a permissible partial transition to a superparamagnetic state in regions with a grain size of less than 100 nm. The ordered magnetic structure, the small size of the domain, and the coexistence of ferromagnetic and superparamagnetic regions, although they reduce the maxi-mum value of the shielding efficiency, significantly expand the working range in the nanostruc-tured permalloy shielding coatings. As a result, a dependence between the grain and domain structure and the efficiency of magnetostatic shielding was found. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. ; This research was funded by the European Union?s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant number 861145. And The APC was funded by the European Union?s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 861145.

Linear and mass ranges of protons and argon ions in aluminum, alumina, bismuth, and W77.7Cu22.3 composite shields were calculated using the SRIM software package. It is shown that the protection efficiency against high-energy ions by materials with large atomic charge (Z) values is higher, from the position of linear ranges of particles, and lower, from the position of mass ranges, in comparison with materials with low Z values. The dependence of the threshold energy on the serial number of particles for aluminum, bismuth, and composite W77.7Cu22.3 shields is determined. The ionization loss spectra for the passage of both protons with an energy of 20 MeV and krypton ions with an energy of 7.75 GeV through multilayer Bi/Al/Al2O3 and Al/Al2O3/Bi structures were calculated. These results showed that the braking of high-energy particles in the case when the first layer contains a heavy element is higher than in the case when the first layer contains a light element. The influence of the sequence in the arrangement and thickness of the layers in the multilayer structures of the Bi/Al/Al2O3 system on the efficiency of protection against high-energy ions was studied. It is shown that the nature of the dependences R(E) and ion energy losses are determined by the sequence of arrangement of individual layers, which is due to the difference in the conversion of the spectra by the material of the first layer. The studied radiation shields can be used in aerospace and nuclear technologies, as well as in many scientific and medical devices, and can be used to protect against the effects of a wide range of ionizing radiation (electrons, protons, heavy charged particles, etc.).

Microelectronic products are widely used in aerospace, aviation, military and nuclear engineering. However, they are very sensitive to various ionizing radiations (electrons, protons, heavy charged particles, X-ray and gamma radiation). The common used material for radiation protection is lead. In recent years, bismuth deposition has become an interesting subject for the electrochemical community because of bismuth's unique electrical, physical and chemical properties. There is a limited number of authors dealing with continuous bismuth films onto metallic substrates by electrodeposition. The conditions of electrochemical deposition of bismuth and the structure of coatings were examined. Electrochemical deposition with the inputted various organic additives and without them was carried out. It is shown that bismuth coatings have a rhombohedral lattice, and thаt adding of a number of organic additives into the electrolyte results changing in a coatings growth texture. The protection efficiency of shields based on bismuth under 1.6–1.8 MeV electron irradiation energy was measured. The electron beam attenuation efficiency was estimated by changing of current-voltage characteristics of semiconductor test structures which were located behind the shields and without them. It has been determined that bismuth shields with 2 g/cm2 reduced thickness and attenuation coefficient of 156 have optimal protection effectiveness and mass dimensional parameters. ; Современные изделия микроэлектронной техники широко применяются в ракетно-космической, авиационной, военной и атомной технике. Однако данные изделия весьма чувствительны к воздействию различных ионизирующих излучений (электроны, протоны, тяжелые заряженные частицы, рентгеновское и гамма-излучения). В настоящее время спектр синтезируемых материалов достаточно широк, ряд из них может быть перспективен для использования в качестве экранов радиационной защиты. В качестве материала экранов, эффективно поглощающих высокоэнергетические излучения, обычно используют тяжелые элементы. Наиболее широко применяемый тяжелый металл – свинец, но он имеет ряд недостатков. Висмут является нетоксичным и обладает невысокой стоимостью, а широкие технологические возможности получения делают его весьма актуальным для применения в качестве материала для радиационной защиты. Исследованы условия электрохимического осаждения и структура покрытий висмута, а также влияние на них различных органических добавок. Показано, что покрытия на основе висмута имеют ромбоэдрический тип кристаллической решетки, а введение в электролит ряда органических добавок приводит к изменению текстуры роста покрытий. Установлено, что с ростом толщины покрытий микроструктура изменяется от дендридной, крупнокристаллической, – к мелкодисперсной. Изучена эффективность радиационной защиты экранов на основе висмута при облучении электронами с энергией 1,6–1,8 МэВ. Эффективность ослабления электронного потока оценивалась по изменению вольтамперных характеристик тестовых МОП-транзисторных структур, расположенных за экранами и без экранов. Установлено, что оптимальными с точки зрения эффективности защиты и массогабаритных параметров являются экраны из висмута характеризующиеся значениями приведенной толщины 2 г/см2 и коэффициентом ослабления, равным 156.

Bi nanocrystalline films were formed from perchlorate electrolyte (PE) on Cu substrate via electrochemical deposition with different duration and current densities. The microstructural, morphological properties, and elemental composition were studied using scanning electron microscopy (SEM), atomic force microscopy (AFM), and energy-dispersive X-ray microanalysis (EDX). The optimal range of current densities for Bi electrodeposition in PE using polarization measurements was demonstrated. For the first time, it was shown and explained why, with a deposition duration of 1 s, co-deposition of Pb and Bi occurs. The correlation between synthesis conditions and chemical composition and microstructure for Bi films was discussed. The analysis of the microstructure evolution revealed the changing mechanism of the films' growth from pillar-like (for Pb-rich phase) to layered granular form (for Bi) with deposition duration rising. This abnormal behavior is explained by the appearance of a strong Bi growth texture and coalescence effects. The investigations of porosity showed that Bi films have a closely-packed microstructure. The main stages and the growth mechanism of Bi films in the galvanostatic regime in PE with a deposition duration of 1–30 s are proposed. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. ; Government Council on Grants, Russian Federation ; 2.34 ; Funding: The work was performed with support of State Scientific and Technical Program "Nanotech" (task No. 2.34), Branch Scientific and Technical Program "Nanotechnology and Nanomaterials" (task No. 1), Act 211 of Government of Russian Federation (contract No. 02.A03.21.0011). Additionally, the work was partially supported by the Grant of World Federation of Scientists (Geneva, Switzerland).