Стабилизация шумовых параметров при отжиге высоколегированных структур диодов – генераторов шума

Stabilization of residual point defects at the finishing stages of noise diodes can be ensured by the selection of appropriate ignition modes and the environment of its conduct. The method and technology of reducing the concentration of point defects in the structure of p-n-transition, taking into account the content of impurities of secondary metals, oxygen and nitrogen is proposed. It has been established that the burning of readymade structures and diodes of noise generators in nitrogen environments at temperatures of 450…600 °С for (80 ± 3) min leads to an increase in spectral noise density and a significant (twice) reduction of its unevenness. The most important result of this burn is a reduction in the spread of the average values of the noise parameters studied: by 61.2 % in effective noise voltage; spectral density by 34.2 %; at the boundary frequency of the signal by 34.9 %; in non-linear density by 25.9 %. This improves the quality of random numerical sequences in information protection software systems.Стабилизация остаточных точечных дефектов на финишных этапах изготовления шумовых диодов может быть обеспечена подбором соответствующих режимов отжига и среды его проведения. Предложен метод и технология снижения концентрации точечных дефектов в структуре p-n-перехода с учетом содержания в структурах примесей вторичных металлов, кислорода и азота. Установлено, что отжиг готовых структур и диодов генераторов шума в среде азота при температурах 450…600 °С в течение (80 ± 3) мин приводит к повышению спектральной плотности шума и значительному (почти двукратному) снижению ее неравномерности. Важнейшим результатом этого отжига является снижение разброса средних значений исследуемых параметров шума: по эффективному напряжению шума – на 61,2 %; по спектральной плотности – на 34,2 %; по граничной частоте сигнала – на 34,9 %; по нелинейности спектральной плотности – на 25,9 %. Это позволяет улучшить качество случайных числовых последовательностей в программно-аппаратных комплексах защиты информации

Влияние технологических примесей на электрофизические параметры МОП-транзистора

It is shown that the quality of gate dielectric has a determinative impact on electrical physical parameters of MOS transistors. Contamination of material by technological impurities during the manufacturing process is the reason for the deterioration of electrical physical parameters of MOS transistors. Sources of contamination can be components of technological equipments, as well as the materials and reagents.Исследованы ВАХ МОП-транзисторов, созданных по эпитаксиально-планарной технологии в различное время с использованием идентичных технологических материалов по аналогичным технологическим маршрутам. Установлено, что электрофизические характеристики МОП-транзисторов существенным образом зависят от качества подзатворного диэлектрика. Наличие дополнительного встроенного заряда в диэлектрике, а также быстрых поверхностных состояний на границе раздела Si-SiO2 приводят как к увеличению порогового напряжения, так и к снижению тока и напряжения насыщения, крутизны характеристики МОП- транзистора в линейной области и в области насыщения, проводимости структуры в линейной области. Возрастают также токи утечки затвора. Показано, что причиной ухудшения электрофизических параметров МОП-транзисторов является загрязнение материала технологическими примесями (Fe, Cl, K, Ca, Ti, Cr, Cu, Zn и др.) во время производственного процесса. Источниками загрязнений могут служить как детали и узлы технологических установок, так и используемые материалы и реактивы

Experimental studies of complex crater formation under cluster implantation of solids

The results of a systematic study of surface defect formation after energetic Ar$_n^+$ (n = 12, 22, 32, 54) and Xe$_n^+$ (n = 4, 16) cluster ion implantation into silicon and sapphire are presented. Implantation energies vary from 3 to 18 keV/ion. Two cases of comparative studies are carried out: the same cluster species are implanted into two different substrates, i.e. Ar$_n^+$ cluster ions into silicon and sapphire and two different cluster species Ar$_n^+$ and Xe$_n^+$ are implanted into the same kind of substrate (silicon). Atomic force, scanning electron and transmission electron microscopies (AFM, SEM and TEM) are used to study the implanted samples. The analysis reveals the formation of two types of surface erosion defects: simple and complex (with centrally positioned hillock) craters. It is found that the ratio of simple to complex crater formation as well as the hillock dimensions depend strongly on the cluster species, size and impact energy as well as on the type of substrate material. Qualitative models describing the two comparative cases of cluster implantation, the case of different cluster species and the case of different substrate materials, are proposed

Design and Fabrication of Photonic Microstructures by Holographic Lithography and Pattern Transformation

The creation of periodic structures in nano- or micro-scale is an exciting challenge of materials science. Meanwhile, the structures with alternating periodic dielectric constants, known as photonic crystals, are great potentials for many applications in optical integrated circuits. In this dissertation, we design and fabricate periodic two- (2D) and three-dimensional (3D) photonic microstructures with desired symmetry, scalable size or novel functionality (e.g. anisotropic feature) using holographic lithography (HL) technique and via harnessing mechanical instability in different polymer systems. In fabrication of 3D diamond-like photonic structure via four-beam single-exposure HL, we quantitatively analyze the lattice distortion due to refraction effect and photoresist shrinkage, which decreases the symmetry of the resulting structure, thus degrading the quality of photonic bandgap (PBG) properties. To address the optical challenge in fabrication of a perfect 3D photonic crystal using four-beam single-exposure HL approach, we design dual-beam triple-exposure HL and fabricate size-scalable diamond-like structure with minimal distortion. We also investigate the robustness of the optical setup, and find that for a large size structure, a small deviation of beam angles may lead to a significant change of lattice size whereas the translational symmetry of SU-8 structure remains reasonably close to face-center-cubic. Besides the 3D holographic fabrication, we develop an efficient method to create a rich library of 2D photonic structures with anisotropic unit cells via harnessing of pattern transformation of an elastomeric poly(dimethylsiloxane) (PDMS) membrane. We then study the PBG properties of 2D Si post arrays with structural symmetries same as those deformed 2D photonic structures, and their tolerance to the structural deviation. To reveal the underlying mechanisms of pattern transformation and the potential for highly ordered complex structures, we systematically study the kinetic process of capillary induced pattern transformation and recovery when swelling and drying 2D poly(2-hydroxyethyl methacrylate) (PHEMA) membranes with a square lattice of micron-sized cylindrical holes from water repeatedly. We find that the PHEMA membrane undergo different modes of instability during drying: when the internal tension is low, the hole reduces size but retains the shape, in a mode of breathing; when the tension is high, the square lattice bifurcated into a diamond plate pattern with neighboring slits perpendicular to each other, in a mode of buckling. Meanwhile, there are many antiphase boundaries (APBs) formed in the diamond plate pattern, where the morphology (either random or aligned) is dependent on the moving speed of the water front. Using dynamic Monte Carlo method we simulate the nucleation, growth and APB formation in pattern transformation and recovery processes, which matches qualitatively with the experimental results. Finally, we suggest a new strategy of shaping the APBs toward the creation of a single crystal transformed pattern

Cluster ion beam facilities

A brief state-of-the-art review in the field of cluster-surface interactions is presented. Ionised cluster beams could become a powerful and versatile tool for the modification and processing of surfaces as an alternative to ion implantation and ion assisted deposition. The main effects of cluster-surface collisions and possible applications of cluster ion bieams are discussed. The outlooks of the Cluster Implantation and Deposition Apparatus (CIDA) being developed in Goteborg University are shown

За кадры. 1980. № 36 (2260)

Практика помогла / В. МашничНаграда за творчество / Б. Лукутин"Север" отправляется на Север / Ю. ДементьевТрудно наверстать упущенное / А. Д. ЧесалинУчеба молодых преподавателей / Л. М. СедоковРоль интеллигенции в социалистическом обществе / Г. ЯловскаяЗа красоту родного городаКак это называется? Тревожный сигнал из библиотеки / А. ЩербининНовая рота / С. ДутовПод контролем трудовая дисциплина / В. КовалевЛьготы работающим пенсионерам / З. КошкоСтройотрядовцам / Л. ЧемезоваНа болотной проплешине шара земного… / А. Р. РубанНе видел войны, не знаю… / В. ТюлькинЗа эту легкость мы еще заплатим... / С. БорзуноваПраздник / А. И. КазанцевПремьера оперы / Р. ТомиловаСотрудники открывают сезон / А. Д. МитаенкоЖдем вас, дарящие жизнь / Г. БубеннаяЧП обсуждено, меры приняты / Г. Барченк

Stabilization of noise parameters during annealing of highly alloyed structures of noise diodes

Стабилизация остаточных точечных дефектов на финишных этапах изготовления шумовых диодов может быть обеспечена подбором соответствующих режимов отжига и среды его проведения. Предложен метод и технология снижения концентрации точечных дефектов в структуре p-n-перехода с учетом содержания в структурах примесей вторичных металлов, кислорода и азота. Установлено, что отжиг готовых структур и диодов генераторов шума в среде азота при температурах 450…600 °С в течение (80 ± 3) мин приводит к повышению спектральной плотности шума и значительному (почти двукратному) снижению ее неравномерности. Важнейшим результатом этого отжига является снижение разброса средних значений исследуемых параметров шума: по эффективному напряжению шума – на 61,2 %; по спектральной плотности – на 34,2 %; по граничной частоте сигнала – на 34,9 %; по нелинейности спектральной плотности – на 25,9 %. Это позволяет улучшить качество случайных числовых последовательностей в программно-аппаратных комплексах защиты информации. Stabilization of residual point defects at the finishing stages of noise diodes can be ensured by the selection of appropriate ignition modes and the environment of its conduct. The method and technology of reducing the concentration of point defects in the structure of p-n-transition, taking into account the content of impurities of secondary metals, oxygen and nitrogen is proposed. It has been established that the burning of ready-made structures and diodes of noise generators in nitrogen environments at temperatures of 450…600 °С for (80 ± 3) min leads to an increase in spectral noise density and a significant (twice) reduction of its unevenness. The most important result of this burn is a reduction in the spread of the average values of the noise parameters studied: by 61.2 % in effective noise voltage; spectral density by 34.2 %; at the boundary frequency of the signal by 34.9 %; in non-linear density by 25.9 %. This improves the quality of random numerical sequences in information protection software systems

Experimental studies of complex crater formation under cluster implantation of solids

The results of a systematic study of surface defect formation after energetic Ar$_n^+$ (n = 12, 22, 32, 54) and Xe$_n^+$ (n = 4, 16) cluster ion implantation into silicon and sapphire are presented. Implantation energies vary from 3 to 18 keV/ion. Two cases of comparative studies are carried out: the same cluster species are implanted into two different substrates, i.e. Ar$_n^+$ cluster ions into silicon and sapphire and two different cluster species Ar$_n^+$ and Xe$_n^+$ are implanted into the same kind of substrate (silicon). Atomic force, scanning electron and transmission electron microscopies (AFM, SEM and TEM) are used to study the implanted samples. The analysis reveals the formation of two types of surface erosion defects: simple and complex (with centrally positioned hillock) craters. It is found that the ratio of simple to complex crater formation as well as the hillock dimensions depend strongly on the cluster species, size and impact energy as well as on the type of substrate material. Qualitative models describing the two comparative cases of cluster implantation, the case of different cluster species and the case of different substrate materials, are proposed