Features of Electronic Emission from Surface of Dielectric Thin-film Materials with Ion-beam Etching

This work presents a series of experimental studies aimed at validating the main theoretical aspects of the ion-electron emission in conditions of ion-beam etching and lookup the possibility of practical realiza-tion of the method of operative control processes ion-beam etching different dielectric thin film materials of electronic technics. In the real article the estimation of influence of the pointed superficial potential is conducted in dielec-tric tape on the integral signal of secondary electrons at an ionic etch. The electric field strength in dielectric film under the influence of the induced potential creates prereq-uisites for the emergence of "Malterovskay" emission, defined by properties actually dielectric and proper-ties of the substrate. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3627

Features of Ion-Electronic Emission from Surface of Semiconductors

The results of the research value of the current of the secondary electrons in the ion-beam etching of various semiconductors. Shows the setup and electrical circuit of the experiment. An experimental study to determine the dependence of the current of the secondary electrons from the band gap Eg and the height of the potential barrier (electron affinity) eχ. It is shown that in the conditions of ion-beam etching of the semiconductor is the penetration of the electric field, which leads to a shift of the energy levels of electrons in the surface layer. Found that the ion-electronic signal emission silicon n-type is higher than the p-type silicon. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3366

ИССЛЕДОВАНИЕ ИОННО–ЭЛЕКТРОННОЙ ЭМИССИИ В ПРОЦЕССЕ РЕАКТИВНОГО ИОННО–ЛУЧЕВОГО ТРАВЛЕНИЯ ДИЭЛЕКТРИЧЕСКИХ ТОНКОПЛЕНОЧНЫХ ГЕТЕРОСТРУКТУР

This work presents a series of experimental studies aimed at validating  the  main theoretical aspects of ion−electron emission. Possibilities of practical implementation of the  method of operative control  of reactive ion−beam etching of different dielectric thin film materials for electronics have been found.To obtain results on electron emission we have conducted a series of experiments with a specially  synthesized thin−film multilayer hetero- geneous compositions, i.e. Si3N4/Si, Ta2O5/Al/Si and Al/TiO2/Si. Assessment of the effect of induced surface potential in the dielectric film on the integral signal of secondary electrons during reactive ion− beam etching allows one to confirm the dependence of the emission properties of thin dielectric films on the  electric field formed in the dielectric by the  surface potential induced by the  ion beam during reactive ion−beam etching.We have noted that the secondary electron current emitted from the surface of dielectric films deposited on substrates of different materials differs in magnitude, i.e., it is determined by the emission properties of the substrate.The electric field produced in the dielectric film by the induced potential creates preconditions for the  emergence of Malter emission deter- mined by the properties of the dielectric and the substrate.Представлена серия экспериментальных исследований с целью подтверждения основных  теоретических аспектов ионно−электронной эмиссии. Установлена возможность практической реализации метода оперативного контроля процессов реактивного ионно−лучевого травления различных диэлектрических тонкопленочных материалов электронной техники. Проведена серия экспериментов по изучению  электронной эмиссии на специально сформированных тонкопленочных  многослойных гетерокомпозициях: Si3N4/Si, Ta2O5/Al/Si and Al/TiO2/Si.Приведена оценка  влияния наведенного поверхностного потенциала в диэлектрической пленке  на интегральный сигнал  вторичных электронов при реактивном ионно−лучевом травлении. Обоснована зависимость эмиссионных свойств тонких диэлектрических пленок от электрического поля, образованного в диэлектрике поверхностным потенциалом, наводимым ионным пучком в процессе реактивного ионно− лучевого травления.Отмечено, что уровень тока вторичных электронов с поверхности диэлектрических пленок,  осажденных на подложки из различных материалов, отличается по величине, т. е. определяется эмиссионными свойствами подложки. Показано, что напряженность электрического поля, возникающая в диэлектрической пленке  под влиянием наведенного потенциала, создает предпосылки для возникновения малтеровской эмиссии, определяемой свойствами собственно диэлектрика и свойствами подложки

ОСОБЕННОСТИ ИОННО–ЭЛЕКТРОННОЙ ЭМИССИИ С ПОВЕРХНОСТИ ПОЛУПРОВОДНИКОВЫХ МАТЕРИАЛОВ В ПРОЦЕССЕ РЕАКТИВНОГО ИОННО–ЛУЧЕВОГО ТРАВЛЕНИЯ

The existing methods of diagnosis of solid surfaces in ion− plasma processes have been analyzed. We found that the most efficient method of estimating surface condition, determining the transition of the etching process from one layer to another and determining the end of the etching process is the registration of ion−electronic emission during ion−beam etching. Results on secondary electron current for ion beam etching of various semiconductors have been reported. We show the experimental setup and describe the electric circuit for the detection of secondary electrons. An experimental study has been carried out to determine the dependence of secondary electron current on the band gap Eg and the height of the potential barrier (electron affinity) χ of Ge, Si, GaAs, GaP and SiC semiconductor materials. We found no clearly expressed dependence of integral signal of ion−electronic emission on Eg and χ. We show that under the conditions of ion beam etching under the influence of the surface potential the electric field penetrates in the semiconductor volume, leading to a shift in the energy levels of electrons in the surface layer and a change in the secondary electron current due to the appearance of autoelectronic emission. We found that the signal of ion−electronic emission in n−type silicon is higher than in p−type silicon. A model of ion−electronic emission from the surface of semiconductors is presented for the conditions of ion−beam etching, consisting of: emission with the participation of conductivity band electrons, emission due to the direct transition of electrons in the ion – atom system, and autoelectronic emission under the influence of surface potential. Рассмотрены существующие методы диагностики поверхности твердых тел при ионно−плазменных процессах. Установлено, что наиболее эффективным методом оценки состояния поверхности, определения перехода процесса травления от одного слоя к другому и окончания процесса травления является регистрация ионно−электронной эмиссии в процессе ионно−лучевого травления. Представлены результаты исследований значения тока вторичных электронов при ионно−лучевом травлении различных полупроводников. Приведена электрическая схема эксперимента, описан узел регистрации вторичных электронов. Экспериментально определены зависимости тока вторичных электронов от ширины запрещенной зоны Eg и высоты потенциального барьера (сродства к электрону) χ полупроводниковых материалов Ge, Si, GaAs, GaP, SiC. Четко выраженной зависимости интегрального сигнала ионно−электронной эмиссии от Eg и χ не установлено. Показано, что в условиях ионно−лучевого травления под влиянием поверхностного потенциала происходит проникновение электрического поля в объем полупроводника, что приводит к смещению уровней энергии электронов в приповерхностном слое и изменению значения тока вторичных электронов за счет возникновения автоэлектронной эмиссии. Установлено, что сигнал ионно−электронной эмиссии для кремния n−типа проводимости выше, чем для кремния p−типа. Представлена модель ионно−электронной эмиссии с поверхности полупроводников в условиях ионно−лучевого травления, состоящая из: эмиссии с участием электронов зоны проводимости, эмиссии за счет прямого перехода электронов системы ион — атом, автоэлектронной эмиссии под влиянием поверхностного потенциала.

DETERMINATION OF THE MINIMUM RESERVE INFUSION SOLUTIONFOR INTENSIVE CARE IN EMERGENCY AID TO VICTIMS EMERGENCY

Purpose: to develop a science-based methodology for determining the need for infusion solutions needed to provide emergency medical care and follow-up treatment of the aff ected population in the liquidation of the health consequences of emergencies.Materials and methods: the analysis of legislative and regulatory framework in а sphere of public drug coverage for emergency medical assistance in emergencies. Th e methodological basis of research were the principles of the system, an integrated, process, logical framework approach to study the organization of activities of pharmacy chains in emergencies.Results: putting into practice the proposed evidence-based management allows health authorities and State Disaster Medicine Service plan and calculate an amount need of infusion solutions for emergency medical care in the aft ermath of the loss of health in emergencies. Application of the proposed method to optimize rational use of budgetary funds for the establishment of local, district and regional reserves infusion solutions for the liquidation of consequences of emergency situations.Summary: the proposed planning approach of minimum reserves of intravenous fl uids to provide intensive therapy requires further improvement of theoretical and methodological basis

Компьютерное моделирование перенапряжений в распределительных сетях 6–10 кВ при однофазных замыканиях на землю

Nowadays, when designing and operating electric power systems, special attention is paid to predicting emergency situations and minimizing losses in case they occur. The most common method of overvoltage investigations is the use of simulation models in specialized application packages, which imposes additional qualification requirements on the electrical engineer.The authors propose modeling technologies and a software tool for modeling and research of overvoltages that occur in 6–10 kV distribution networks at single-phase ground faults, including the method of visual design of the distribution network through the use of information technology and automated generation of mathematical model for its further study to analyze overvoltages.В настоящее время при проектировании и эксплуатации электроэнергетических систем особое внимание уделяется прогнозирования возникновения аварийных ситуаций и минимизации потерь в случае их появления. Наиболее распространёнными методом исследования перенапряжений являются применение имитационных моделей в специализированных прикладных пакетах, что накладывает дополнительные квалификационные требования на энергетика-проектировщика.Авторами предлагается технологии моделирования и программное средство для моделирования и исследования перенпряжений, возникающих в распределительных сетях 6–10 кВ при однофазных замыканиях на землю, включающее методику визуального проектирования распределительной сети посредством применения информационных технологий и автоматизированную генерацию математической модели для её дальнейшее исследование с целью анализа перенапряжений

KLEVER: An experiment to measure BR(KL→π0ννˉK_L\to\pi^0\nu\bar{\nu}) at the CERN SPS

Precise measurements of the branching ratios for the flavor-changing neutral current decays $K\to\pi\nu\bar{\nu}$ can provide unique constraints on CKM unitarity and, potentially, evidence for new physics. It is important to measure both decay modes, $K^+\to\pi^+\nu\bar{\nu}$ and $K_L\to\pi^0\nu\bar{\nu}$, since different new physics models affect the rates for each channel differently. The goal of the NA62 experiment at the CERN SPS is to measure the BR for the charged channel to within 10%. For the neutral channel, the BR has never been measured. We are designing the KLEVER experiment to measure BR($K_L\to\pi^0\nu\bar{\nu}$) to $\sim$20% using a high-energy neutral beam at the CERN SPS starting in LHC Run 4. The boost from the high-energy beam facilitates the rejection of background channels such as $K_L\to\pi^0\pi^0$ by detection of the additional photons in the final state. On the other hand, the layout poses particular challenges for the design of the small-angle vetoes, which must reject photons from $K_L$ decays escaping through the beam exit amidst an intense background from soft photons and neutrons in the beam. Background from $\Lambda \to n\pi^0$ decays in the beam must also be kept under control. We present findings from our design studies for the beamline and experiment, with an emphasis on the challenges faced and the potential sensitivity for the measurement of BR($K_L\to\pi^0\nu\bar{\nu}$).Comment: 13 pages, 4 figures. Submitted as input to the 2020 update of the European Strategy for Particle Physics. v2: Included authors unintentionally omitted in v

Measurement of associated charm production induced by 400 GeV/c protons

An important input for the interpretation of the measurements of the SHiP ex- periment is a good knowledge of the differential charm production cross section, including cascade production. This is a proposal to measure the associated charm production cross section, employing the SPS 400 GeV/c proton beam and a replica of the first two interaction lengths of the SHiP target. The detection of the produc- tion and decay of charmed hadron in the target will be performed through nuclear emulsion films, employed in an Emulsion Cloud Chamber target structure. In order to measure charge and momentum of decay daughters, we intend to build a mag- netic spectrometer using silicon pixel, scintillating fibre and drift tube detectors. A muon tagger will be built using RPCs. An optimization run is scheduled in 2018, while the full measurement will be performed after the second LHC Long Shutdown

Search for π⁰ decays to invisible particles

The NA62 experiment at the CERN SPS reports a study of a sample of 4 × 109 tagged π0 mesons from K+ → π+π0(γ), searching for the decay of the π0 to invisible particles. No signal is observed in excess of the expected background fluctuations. An upper limit of 4.4 × 10−9 is set on the branching ratio at 90% confidence level, improving on previous results by a factor of 60. This result can also be interpreted as a model- independent upper limit on the branching ratio for the decay K+ → π+X, where X is a particle escaping detection with mass in the range 0.110–0.155 GeV/c2 and rest lifetime greater than 100 ps. Model-dependent upper limits are obtained assuming X to be an axion-like particle with dominant fermion couplings or a dark scalar mixing with the Standard Model Higgs boson