Article
Влияние различных видов радиации на характеристики кремний-германиевых гетеропереходных транзисторов
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.
An electro-thermal modeling of modern SiGe and Si bipolar transistor structures using TCAD Sentaurus Synopsys has been carried out. It has been shown that for SiGe heterojunction bipolar transistors, operating at high current density, the internal temperature is higher than for identical Si transistors. As a result a stronger degradation of the device parameters and electrical characteristics is observed.
A compact BSIMSOI-RAD macromodel for SOI/SOS CMOS transistors is developed that takes into account the radiation effects. An automated procedure for determination of macromodel parameters is described and shown to be useful for analyzing radiation hardness of CMOS IC fragments depending on the total absorbed dose. The simulation time is estimated.
The effects of proton irradiation on SiGe heterojunction bipolar transistor (HBT) are investigated using Synopsys/ISE TCAD tool. To account for the impact of proton irradiation models for carrier lifetime degradation under irradiation are included in the program. The results of modeling the impact of protons of different energies are presented. For SiGe HBT increase in the base current for low-energy protons is more intense than for high-energy protons. We also present the simulation results of SiGe HBT dc and ac performance after proton exposure. The simulation results are in good agreement with experimental data.
The possibilities of commercial SPICE are expanded in the new field—space environment electronics design. For this purpose, the set of BJT and MOSFET models with account for radiation influence is included into commercial SPICE device library. The characteristics of devices and circuits subjected to space radiation exposure (gamma-rays, protons, neutrons, electrons, heavy ions) are presented and examined with emphasis on application for radiation hardened electronics systems.
An EKV-RAD macromodel for SOI/SOS MOSFET with account for radiation effects is developed using a subcircuit approach. As an addition to the standard version of the EKV model 1) radiation dependencies of parameters VTO, GAMMA, KP, E0 are introduced and 2) additional circuit elements to account for floating-body effects and radiation-induced leakage currents under static and dynamic radiation influence are connected. Maximum simulation error is 5–7% in the dose range up to 1 Mrad. It is shown that EKV-RAD spends less CPU time by 15–30% for analog and 40–50% for digital SOI/SOS CMOS circuits simulations compared to BSIMSOI-RAD model.
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.