Влияние изохронного и изотермического отжига на процесс восстановления коэффициента усиления по току кремниевого биполярного транзистора, подвергнутого воздействию радиации
In article it is considered questions of a settlement assessment of probability of no-failure operation of radio-electronic systems of spacecrafts at influence of low-intensive radiation of a space. The description of characteristics of ionizing radiation and methods of calculation of the saved-up dose is provided. The main stages of formation of failure rate model of integrated chips
An overview is given of published papers on investigations of ionizing radiation influence (gamma, neutron, and proton) on characteristics of silicon-germanium heterojunction transistors -- elements of SiGe BiCMOS integrated circuits of 4 generations with design rules 0.25, 0.18, 0.13, and 0.09 um. Experimental data are explained on the basis of modern understanding of radiation effects in bipolar junction transistors with proper consideration of silicon-geramnium heterostructure properties. It is shown that major SiGe HBT parameters (beta, gm, VA, fT, fmax etc.) are less succeptible to radiation influence unlike silicon transistors. In total absorbed dose, SiGe HBTs feature unique hardness, that is 50-100 Mrads for the latest SiGe technology.
The effects of neutron irradiation on both Si bipolar junction transistor (BJT) and SiGe heterojunction transistor (HBT) are investigated using Synopsys/ISE TCAD tool. For this purpose the carrier lifetime degradation under irradiation models are included in the program. It was established that at fluence 4×1013 cm-2 the Si BJT exhibited a degradation in current gain of 50% for high level and 80% for low level of E-B junction injection. For SiGe HBT at fluences as high as 1015 cm-2 the degradation of peak current gain is less than 40%, and the device maintains a peak current gain of 80 – 100 after 1015 cm-2. The cut-off and maximum oscillations frequencies are small sensitive to neutron irradiation. The simulation results are in good agreement with experimental data.
I-V-characteristics of an irradiated transistor in many cases should be measured inside the radiation chamber with long cables, which introduces noticeable measurement error. In this paper I-V-characteristics of an irradiated bipolar junction transistor measured with the 4-wire and the 2- wire circuits are presented and compared to direct (without cables) measurements. Significant enlargement of measurement error for the 2-wire method in comparison with the 4-wire method is shown for different currents.
The article discusses estimation of the probability of failure-free operation of spacecraft electronic systems under the influence of cosmic radiation. The article describes characteristics of ionizing radiation and the techniques for calculating the cumulative dose and probability of catastrophic failure. Main steps for the formation of the integrated circuit failure rate model under the low-intensity radiation exposure are illustrated.
Generalized error-locating codes are discussed. An algorithm for calculation of the upper bound of the probability of erroneous decoding for known code parameters and the input error probability is given. Based on this algorithm, an algorithm for selection of the code parameters for a specified design and input and output error probabilities is constructed. The lower bound of the probability of erroneous decoding is given. Examples of the dependence of the probability of erroneous decoding on the input error probability are given and the behavior of the obtained curves is explained.
The dynamics of a two-component Davydov-Scott (DS) soliton with a small mismatch of the initial location or velocity of the high-frequency (HF) component was investigated within the framework of the Zakharov-type system of two coupled equations for the HF and low-frequency (LF) fields. In this system, the HF field is described by the linear Schrödinger equation with the potential generated by the LF component varying in time and space. The LF component in this system is described by the Korteweg-de Vries equation with a term of quadratic influence of the HF field on the LF field. The frequency of the DS soliton`s component oscillation was found analytically using the balance equation. The perturbed DS soliton was shown to be stable. The analytical results were confirmed by numerical simulations.
Radiation conditions are described for various space regions, radiation-induced effects in spacecraft materials and equipment components are considered and information on theoretical, computational, and experimental methods for studying radiation effects are presented. The peculiarities of radiation effects on nanostructures and some problems related to modeling and radiation testing of such structures are considered.
This volume presents new results in the study and optimization of information transmission models in telecommunication networks using different approaches, mainly based on theiries of queueing systems and queueing networks .
The paper provides a number of proposed draft operational guidelines for technology measurement and includes a number of tentative technology definitions to be used for statistical purposes, principles for identification and classification of potentially growing technology areas, suggestions on the survey strategies and indicators. These are the key components of an internationally harmonized framework for collecting and interpreting technology data that would need to be further developed through a broader consultation process. A summary of definitions of technology already available in OECD manuals and the stocktaking results are provided in the Annex section.