285 research outputs found

    Long-term prediction test procedure for most ICs, based on linear response theory

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    Experimentally, thermal annealing is known to be a factor which enables a number of different integrated circuits (IC's) to recover their operating characteristics after suffering radiation damage in the space radiation environment; thus, decreasing and limiting long term cumulative total-dose effects. This annealing is also known to be accelerated at elevated temperatures both during and after irradiation. Linear response theory (LRT) was applied, and a linear response function (LRF) to predict the radiation/annealing response of sensitive parameters of IC's for long term (several months or years) exposure to the space radiation environment were constructed. Compressing the annealing process from several years in orbit to just a few hours or days in the laboratory is achieved by subjecting the IC to elevated temperatures or by increasing the typical spaceflight dose rate by several orders of magnitude for simultaneous radiation/annealing only. The accomplishments are as follows: (1) the test procedure to make predictions of the radiation response was developed; (2) the calculation of the shift in the threshold potential due to the charge distribution in the oxide was written; (3) electron tunneling processes from the bulk Si to the oxide region in an MOS IC were estimated; (4) in order to connect the experimental annealing data to the theoretical model, constants of the model of the basic annealing process were established; (5) experimental data obtained at elevated temperatures were analyzed; (6) time compression and reliability of predictions for the long term region were shown; (7) a method to compress test time and to make predictions of response for the nonlinear region was proposed; and (8) nonlinearity of the LRF with respect to log(t) was calculated theoretically from a model

    Development of a theoretical model for annealing of radiation damage in semiconductor devices

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    The radiation response of Metal Oxide Semiconductor (MOS) devices and Integrated Circuits (ICs) was studied theoretically. The case of short-term annealing and the rebound effect are modeled mathematically using the linear response theory

    Application of linear response theory to experimental data of simultaneous radiation and annealing response of a CMOS device

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    Results from the application of linear response theory are compared to experimental data from simultaneous radiation and annealing response of a CMOS device. In particular, a method is applied which was developed earlier to determine the characteristic time, t(0), as well as the parameters A and C in the 1n(t) dependence of the linear response function R(t) = -C + A1n(1-t/t(0)). The method is based on a study of the linear response for t being much less than t(0), when R(t) can be expanded in a power series of t: R(t) = R(0) + R'(0)t + 1/2R''(0)t-squared + 1/3R'''(0)t-cubed + ..., where R'(0) and R''(0) are, respectively, the first and second derivatives of R with respect to t. To find the linear response, R(t-t') is substituted in the form of this power series equation into a general equation for the shift of the threshold potential. To test the method, irradiation experiments were conducted on RCA 10(6) rad-hard CMOS IC's. A dose rate of approximately 130 rads/min was used. An IC was irradiated with Co-60 gamma rays for several hours, taking measurements of the threshold potential for one n-channel and one p-channel transistor every ten minutes. For the p-channel transistor, t(0) was found to be approximately 110 min and for the n-channel, t(0) was approximately 70 min. For the p-channel, the theoretical curve deviates from the experimental points only after 70 min; for the n-channel, the deviation takes place after 45 min. Additional findings are discussed and the application of the method to pure annealing is described

    Peculiarities of neutron irradiation influence on GaP light-emitting structures

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    GaP LEDs irradiated by reactor neutrons were studied by optical and electrical methods. The observed emission intensity degradation is related with two factors: 1) radiation fields that destroy bond excitons and 2) decrease in the free charge carrier concentration, which is caused by their capture by radiation defects. Study of currentvoltage characteristics at 77 K by highly precession methods has revealed the appearance of N-shaped negative differential region caused by carrier tunneling onto deep levels in quantum wells, which might exist in initial and irradiated p-n structures. In some cases, improvement of current-voltage characteristics after neutron irradiation is observed. An assumption is made about the radiation-stimulated origin of this effect

    Thermal stability of Ti-C-Ni-Cr and Ti-C-Ni-Cr-Al-Si nanocomposite coatings

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    The results of the microstructure, mechanical and tribological properties investigations of Ti-C-Ni-Cr and Ti-C-Ni-Cr-Al-Si nanocomposite coatings based on amorphous carbon in the initial state and after the annealing to 900 °C are presented. The effect of annealing temperature on the microstructure, tribological and mechanical properties of Ti-C- Ni-Cr and Ti-C-Ni-Cr-Al-Si nanostructured coatings is discussed

    УПРАВЛІННЯ КРЕДИТНОЮ ДІЯЛЬНОСТІ БАНКУ ДЛЯ ЗАБЕЗПЕЧЕННЯ ЙОГО ФІНАНСОВОЇ СТАБІЛЬНОСТІ

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    Concept of financial stability of bank and economic essence of bank’s credit activity are considered in the article. The indexes of financial stability and indexes of efficiency, profitability, liquidity of bank establishment, and also economic indicators and norms of the banking system are analysed.Crediting activation assists the further increase of economy, development and origin of new entities, creation of workplaces, development infrastructure of country, those are basis of financial stability. In parallel, crediting is one direction of banks’ activity, that provides their profitability.The article is dedicated to the analysis of tendencies and features of credit activity of domestic banks. Efficiency of management of credit activity JSC CB "Privatbank" and JSC "Oschadbank" on the modern stage of economic development are analized. Authors analyse the structure of a loan portfolio JSC CB "Privatbank" and JSC "Oschadbank", efficiency of management of a loan portfolio by correlation of basic management parameters - profitability and risk. The analytical estimation of the credit activity state of JSC CB "Privatbank" and JSC "Oschadbank" and its influence on financial stability of the banking system, and also on return on assets of the indicated bank institutions and optimal strategy of banks’ credit activity.The modern state is analysed and practical recommendations are sunstantiated in relation to the improvement of bank institutions’ credit activity with the aim of providing their financial stability.Conclusions about the necessity of efficiency management crediting of domestic banks’ increase by optimal forming and management of a loan portfolio at a minimum level of risk are drawn.В статье рассмотрено понятие финансовой устойчивости банка и экономическая сущность кредитной деятельности банков. Осуществлено аналитическую оценку состояния кредитной деятельности банковских учреждений и ее влияние на финансовую устойчивость банковской системы. Проанализировано современное состояние и обоснованы практические рекомендации по совершенствованию кредитной деятельности банковских учреждений.У статті розглядаються поняття фінансова стабільність банку та економічна сутність кредитної діяльності банку. Аналізуються показники фінансової стабільності та показники рентабельності, прибутковості, ліквідності банківської установи, а також економічні показники та норми банківської системи.Активізація кредитування сприяє подальшому зростанню економіки, розвитку та виникненню нових суб'єктів господарювання, створенню робочих місць, розвитку інфраструктури країни, що є основою фінансової стабільності. Паралельно кредитування є одним з напрямків діяльності банків, що забезпечує їх прибутковість.Стаття присвячена аналізу тенденцій та особливостей кредитної активності вітчизняних банків. Проаналізовано ефективність управління кредитною діяльністю АТ КБ «Приватбанк» та АТ «Ощадбанк» на сучасному етапі економічного розвитку.  Авторами проаналізовано структуру кредитного портфеля АТ КБ «Приватбанк» та АТ «Ощадбанк», ефективність управління кредитним портфелем за співвідношенням основних параметрів управління - прибутковості та ризику. Визначено аналітичну оцінку стану кредитної активності АТ КБ «Приватбанк» та АТ «Ощадбанк» та її вплив на фінансову стабільність банківської системи, а також на рентабельність активів вказаних банківських установ та оптимальну стратегію кредитної діяльності банків.Проаналізовано сучасний стан та обґрунтовано практичні рекомендації щодо поліпшення кредитної діяльності банківських установ з метою забезпечення їх фінансової стабільності.Зроблено висновки про необхідність підвищення ефективності управління кредитуванням вітчизняних банків шляхом оптимального формування та управління кредитним портфелем при мінімальному рівні ризику
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