Frédéric Saigné

SEU Measurements and Simulations in a Mixed Field Environment

Single Event Upset (SEU) measurements were performed using the European Space Agencys (ESA) Standard SEU Monitor in the H4 Irradiation mixed-field test area at CERN. The results, tightly correlated with the radiation environment, are compared with those obtained with the CERN Radiation Monitors (RadMons) as well as with the Monte Carlo simulation of the experimental setup using the FLUKA Monte Carlo transport code. In addition, the SEU cross section of the device for particles and energies not available in standard testing (such as charged pions or GeV-energy hadrons) are simulated and discussed, showing an increase of over a factor 2 for nucleons in the 200 MeV-3 GeV range. A monoenergetic SEU cross section measurement at 120 GeV is included in the analysis.

Testing a Commercial MRAM Under Neutron and Alpha Radiation in Dynamic Mode

Academic and industrial research interest in terrestrial radiation effects of electronic devices has expanded over the last years from avionics and military applications to commercial applications as well. At the same time, the need for faster and more reliable memories has given growth to new memory technologies such as Magnetic (magneto-resistive) Random Access Memories (MRAM), a promising new non-volatile memory technology that will probably replace in the future the current SRAM and FLASH based memories. In this paper, we evaluate the soft error resilience of a commercial toggle MRAM in static and dynamic test mode, under neutron radiation with energies of 25, 50 and 80 MeV as well as under a Californium (Cf-252) alpha source.

Multiple Cell Upset Classification in Commercial SRAMs

While single bit upsets on memories and storage elements are mitigated with either the use of redundancy and/or error correction codes, Multiple-Cell-Upsets (MCU) may become a significant threat to the integrity of systems when the corrupted cells belong to the same word. In this paper, we identify four types of MCUs as they were recorded during several irradiations under an atmospheric-like neutron beam (ISIS facility). An analysis is done on the underlying reasons of occurrence of each MCU type, as well as their shapes and sizes in order to classify them. The results of this work concern a commercial 90 nm SRAM that was tested under an atmospheric neutron beam in static and dynamic mode. It is shown that, when the memory is in dynamic mode, not only the typical MCUs that involve a few flipped cells may appear but also large clusters of upsets are possible to occur with hundreds or even thousands of cells being affected.

Determining Realistic Parameters for the Double Exponential Law that Models Transient Current Pulses

We calculated Single Event Upset (SEU) cross-section as well as the neutron Soft Error Rate (SER) at ground level for three SRAMs (90 nm, 65 nm an 40 nm). For this purpose, we first investigate the transient current pulse induced at each drain electrode, by using the diffusion model for the transient current pulses. Then, we performed the same simulations by replacing each transient current by a simple double exponential law model, for which the parameters were set in order to keep the same fundamental parameters of the diffusion model such as total charge, maximum value of current and its corresponding occurrence time. Our results show a little systematic increase of the cross section while using the double exponential law. Moreover, we showed that only two parameters of the double exponential law are actually required to investigate Single Event Upsets. Finally, we provided for the 90-nm some analytical expression in order to estimate the distribution of parameters that appear in the double exponential law.

Dynamic Test Methods for COTS SRAMs

In previous works, we have demonstrated the importance of dynamic mode testing of SRAM components under ionizing radiation. Several types of failures are difficult to expose when the device is tested under static (retention) mode. With the purpose of exploring and defining the most complete testing procedures and reveal the potential hazardous behaviors of SRAM devices, we present novel methods for the dynamic mode radiation testing of SRAMs. The proposed methods are based on different word address accessing schemes and data background: Fast Row, Fast Column, Pseudorandom, Adjacent (Gray) and Inverse Adjacent (Gray). These methods are evaluated by heavy ion and atmospheric-like neutron irradiation of two COTS SRAMs of 90 nm and 65 nm technology.

Modeling and Investigations on TID-ASETs Synergistic Effect in LM124 Operational Amplifier From Three Different Manufacturers

The synergistic effect between Total Ionizing Dose (TID) and Analog Single Event Transient (ASET) in LM124 operational amplifiers (opamps) from three different manufacturers is investigated. This effect is clearly identified on only two manufacturers by three, highlighting manufacturer dependent. In fact, significant variations were observed on both the TID sensitivity and the ASET response of LM124 devices from different manufacturers. Hypotheses are made on the cause of the differences observed. A previously developed ASET simulation tool is used to model the transient response. The effects of TID on devices are taken into account in the model by injecting the variations of key electrical parameters obtained during Co60 irradiation. An excellent agreement is observed between the experimental responses and the model outputs, independently of the TID level, the bias configuration and the manufacturer of the device.

Energy Dependence of Tungsten-Dominated SEL Cross Sections

The energy dependence of proton-induced Single Event Latchup (SEL) failures is investigated for different Static Random Access Memories (SRAMs) and an Analog-to-Digital Converter (ADC) through experimental measurements in the 30-230 MeV range. It is observed that for several of them, the measurements are not compatible with a saturation below the maximum energy tested. A Monte Carlo based model is proposed that explains the observed cross section increase through the presence of tungsten near the sensitive region and is used to extrapolate the SEL cross section to larger energies. The significant cross section increases expected by the model up to 3 GeV are quantified and discussed, potentially having a strong impact on the failure rate for energetic environments such as high-energy accelerators or the avionics contexts.

SEE Measurements and Simulations Using Mono-Energetic GeV-Energy Hadron Beams

Single Event Upset (SEU) measurements were performed on the ESA SEU Monitor using mono-energetic GeV-energy hadron beams available in the North Experimental Area at CERN. A 400 GeV proton beam in the H4IRRAD test area and a 120 GeV mixed pion and proton beam at the CERN-EU high Energy Reference Field facility (CERF) were used for this purpose. The resulting cross section values are presented and discussed as well as compared to the several hundred MeV case (typical for standard test facilities) from a physical interaction perspective with the intention of providing a more general understanding of the behavior. Moreover, the implications of the cross section dependence with energy above the several hundred MeV range are analyzed for different environments. In addition, analogous measurements are proposed for Single Event Latchup (SEL), motivated by discussed simulation results. Finally, a brief introduction of the future CHARM (CERN High-energy AcceleratoR Mixed facility) test installation is included.

SEL Cross Section Energy Dependence Impact on the High Energy Accelerator Failure Rate

We use a single event latchup (SEL) model calibrated to heavy ion (HI) and proton data below 230 MeV to extrapolate the proton cross section to larger energies and evaluate the impact of the potential cross section increase with energy on the SEL rate in different environments. We show that in the case of devices with a large LET onset for HI and a certain amount of tungsten near the sensitive volume (SV), the calculated failure rates for energetic environments based on monoenergetic test data can significantly underestimate the real value. In addition, we show through measurements using a 480 MeV beam and an inspection of the devices architecture that the model was successful in estimating the SEL cross section and tungsten volume per cell.

Modeling dose effects in electronics devices: Dose and temperature dependence of power MOSFET

Abstract A new TCAD modeling tool taking into account dose effects is presented: E.CO.R.C.E. It allows a study of dose and temperature dependence on a power MOSFET. Modeling results are compared to experimental data. It is shown that threshold voltage shift at room temperature can be modeled with a good accuracy using only one hole trap level. However, temperature effect on threshold voltage shift cannot be fitted with less than four hole traps levels. More generally, this tool allows a better understanding of mechanisms involved during irradiation.