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The role of all natural alpha emitters on the soft-error rate of integrated circuits is quantified. The impact of seven materials is given in FIT per mass unit. For instance, platinum has an isotope that is a natural alpha emitter, which may increase the Soft Error Rate up to 53 FIT/ng. Moreover, secular equilibrium of uranium is simulated by a Monte Carlo method. Only 90 parts per trillion of uranium is enough to explain the emissivity of wafers. Simulations show the trends of the alpha SER with scaling from the 250 nm technology node down to the 90 nm node. The contribution of alpha particles emitted by impurities to the SER is shown to become more important as the feature size decreases. [ABSTRACT FROM AUTHOR]

Information about the 8th European Conference on Radiation and its Effects on Components and Systems which was held in France on September 19-23, 2005 is presented. The conference was attended by several scientists, students, and engineers from industry, government organizations, and research institutes. Moreover, it featured several experts in dealing with radiation related issues including Fred Wrobel, D. Fleetwood, and Michael Moll.

The switched dose rate technique has been proposed as an accelerated test technique for enhanced low-dose-rate sensitivity. The physical mechanisms at play when this technique is applied are investigated in this paper. The variation of Not and Nit is characterized using gated lateral pnp transistors to understand the kinetics of device degradation related to differences in mechanisms between high dose rate and low dose rate irradiations. [ABSTRACT FROM PUBLISHER]

^238\ U and ^232\ Th and their relative daughters are impurity sources responsible for soft errors induced by alpha particles. In this paper, the contribution of each decay chain to the alpha emission rate is evaluated by assuming that secular equilibrium is reached. We show that for the same concentration of uranium and thorium in secular equilibrium, uranium decay chain has an alpha emission rate (AER) two times higher than the thorium decay chain. Furthermore, the contribution of these two decay chains to the Soft Error Rate (SER) and Multiple Cell Upset (MCU) is calculated for a 90 nm and a 65 nm CMOS technology by Monte Carlo simulations by considering a concentration of thorium 1.33 higher than uranium in secular equilibrium condition, which is representative to measurements found in literature. We show in these conditions that uranium has a contribution to the SER and MCU higher than that of thorium. [ABSTRACT FROM AUTHOR]

The enhanced radiation sensitivity exhibited at low dose rate by many bipolar devices remains one of the main concerns for spacecraft reliability. As an accelerated test technique, a new approach based on dose-rate switching experiments has been proposed to characterize bipolar devices. The foundations of this approach are detailed and guidelines for its use are given. [ABSTRACT FROM AUTHOR]

Analog Single Event Transients (ASETs) in two different shunt voltage references used in power management systems are investigated. Little has been published regarding how the dynamic parameter changes induced by external circuit design, such as time constant, damping coefficient or natural frequency affect ASET shapes. Modifications of the dynamic parameters of the circuit are measured by step response measurement. A correlation between dynamic parameters and ASET laser testing results is proposed. This study establishes the correlation between the dynamic parameters of a shunt voltage reference and ASET parameters such as pulse duration, and positive and negative amplitude. [ABSTRACT FROM AUTHOR]

The Synergistic effect between Total Ionizing Dose (TID) and Analog Transient Radiation Effects in Electronics (ATREE) in an operational amplifier (LM124) is investigated. A predictive methodology, based on a previously developed ATREEs simulation tool, is used to model the synergistic phenomena. This phenomenon is simulated for the first time and the duration of the ATREEs' is found to be identical to those measured experimentally. ATREEs induced by high dose-rate X-ray pulses are investigated using a flash X-ray facility. The ATREEs induced in the LM124 operational amplifier configured in three different bias configurations are investigated and simulated. [ABSTRACT FROM PUBLISHER]

Alpha-particle emissivity at wafer-level has been analytically modeled for material layers contaminated by uranium and/or thorium impurities. Our approach evaluates the number (or the fraction) of escaping alpha particles from any monolayer or multilayer of arbitrary material composition. The global emissivity of the (stacked) material and its corresponding alpha-particle energy spectrum can be also analytically derived. The model has been fully validated with Monte Carlo simulation in terms of alpha-particle emissivity and energy spectra for different layer thicknesses and detection threshold energies. Finally, we propose a general nomogram for silicon material directly giving the alpha-particle emissivity versus the silicon contamination level expressed in ppb of uranium and thorium. [ABSTRACT FROM PUBLISHER]

We report a stratospheric flight with a CNES balloon for which we developed a silicon detector in order to obtain data on the atmospheric radiation environment. The number of detected protons is shown to be directly correlated with the altitude. Simulations with the MC-ORACLE code, which uses pre-calculated fluxes with QARM, are in good agreement with our experimental results. [ABSTRACT FROM AUTHOR]

The Synergistic effect between TID and ATREEs (Analog Transient Radiation Effects on Electronics) in an operational amplifier (opamp) (LM124) is investigated for three different bias configurations. An accelerated irradiation technique is used to study these synergistic effects. The impact of TID on ATREEs is found to be identical regardless of whether the irradiation is performed at low dose rate or whether the dose rate is switched from high to low using the Dose Rate Switching (DRS) technique. The correlation between the deviations of the opamp's electrical parameters and the changes of ATREE widths is clearly established. [ABSTRACT FROM AUTHOR]

This paper presents the results of SPICE simulations of terrestrial radiation induced effects on SRAM cells in which resistive-open defects are introduced. This kind of defect is difficult to be detected with standard manufacturing tests. Although the presence of the defect may not affect the memory functionality when not exposed to radiation, it alters the radiation induced error rate of the cell both under static and dynamic conditions. Moreover, the defect can increase the SRAM radiation-induced error rate when operations are applied to the cell (dynamic mode). For the purpose of estimating the impact of resistive-open defects on SRAM radiation sensitivity, we consider defects with different resistive values and compare the analytically calculated error rates during different SRAM operating modes. [ABSTRACT FROM AUTHOR]

Aiming at evaluating new options for radiation monitoring sensors in LHC/SLHC experiments, the radiation responses of FZ and MCz custom made silicon detectors of different geometry have been studied up to about 4\times 10^14~neq /\rm cm^2. The radiation response of the devices under investigation is discussed in terms of material type, thickness and active area influence. [ABSTRACT FROM AUTHOR]

Abstract: A comparison between experimental results on SiO2–Si under swift heavy ion irradiation at normal and grazing incidence is dealt with. After irradiation, the samples were gradually etched in an aqueous hydrofluoric acid solution. Atomic force microscopy has been used to study the evolution of the tracks regarding their extension and shape. At normal incidence, the latent tracks are revealed by chemical etching. Increasing the etching time, nano-hillocks appeared in the depths of each of the conical holes formed at the beginning of the chemical process. When the SiO2 layer is completely removed, nano-bumps are clearly visible at the interface between the two materials. Under grazing incidence (1° of beam inclination), elongated discontinuous tracks are directly observable after irradiation on the SiO2 surface. While with a sequential chemical etching, the intermittent tracks leave room to lengthy craters of decreasing depth, which disappear when the oxide layer is completely etched-away. [Copyright &y& Elsevier]