E. Lorfevre

Physical Model for the Low-Dose-Rate Effect in Bipolar Devices

A physical model of the dose-rate effect in bipolar junction transistors is proposed, based on competition between trapping and recombination of radiation-induced carriers in the oxide. The initial recombination of the carriers is considered in this model, taking into account the temperature effect. The general trends obtained with this model are in very good agreement with experimental data. It is also shown that the dose rate effect depends significantly on oxide quality

Estimation of low-dose-rate degradation on bipolar linear integrated circuits using switching experiments

The low-dose-rate response of five bipolar integrated circuits is evaluated on the basis of switching experiments. Such experiments consist of performing first a high-dose-rate irradiation followed by a low-dose-rate irradiation. Based on these experiments, a time-saving method to predict the low-dose-rate degradation of bipolar linear microcircuits is proposed. This approach provides a good estimate of the low-dose-rate degradation.

The Use of a Dose-Rate Switching Technique to Characterize Bipolar Devices

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.

In Flight Measurements of Radiation Environment on Board the French Satellite JASON-2

This paper presents particle flux measurements (protons and electrons) obtained with the ICARE-NG detector on the JASON-2 orbit (1336 km alt., 66° incl.) for the period June 2008-Aug. 2010. At this altitude, the South Atlantic Anomaly is greatly broadened as compared to lower altitudes. Proton flux measurements are made in the range 27.5-290 MeV and electron flux in the range 1.6-3.6 MeV. A great care was taken to assess the influence of the satellite on the particle measurements. Comparison of measurements with the results of the AP8 MIN model are given for protons, taken into account environment anisotropy.

Review and Analysis of the Radiation-Induced Degradation Observed for the Input Bias Current of Linear Integrated Circuits

It is shown that the variety of shapes of the input current versus dose curve observed in several ICs is due to circuit effects, depending on the architecture, the value of the currents and the bias conditions. When stages are cascaded, the degradation of the second stage may add or subtract current to the collector current of the input transistor. The variations of the collector currents can be evaluated using the variations of the supply current. It is then possible to model the compensation effects using basic equations and study the impact of irradiation conditions. In some cases, the effect of biasing the circuit during irradiation is to reduce the compensation mechanism leading to an stronger increase in the input current. When a peak shaped degradation curve is recorded, annealing may either induce an additional degradation or a recovery depending on which side of the peak irradiation has brought the circuit.

Accelerated Irradiation Method to Study Synergy Effects in Bipolar Integrated Circuits

An accelerated irradiation technique is used to study dose-ASET synergy effects. The impact of TID on SET is found to be identical when the dose rate is switched from high to low or from low to high.

Online dosimetry based on optically stimulated luminescence materials

A version of the Optically Stimulated Luminescence (OSL) sensor specifically developed to monitor the dose online in radiation facilities is presented and calibrated with /sup 60/Co. The lowest dose measurable at the extremity of a 20 m cable is 0.3 mGy.

Investigation on the SEL Sensitive Depth of an SRAM Using Linear and Two-Photon Absorption Laser Testing

Linear and two-photon laser testing is used to investigate the single-event latchup sensitive depth of SRAM CY7C1069 embedded in CARMEN satellite experiment. Results are discussed and compared with heavy ion and flight data.

In flight observation of proton induced destructive single event phenomena

MEX Experience Module is a part of CARMEN2 instrument launched in June 22 2008 aboard JASON2 satellite. This scientific instrument is dedicated to the study of the effects of space radiation environment on various electronic devices. Among all the phenomena studied in this experiment, this paper focuses on the data collected on destructive SEEs: Latch-up on commercial SRAMs and Burnout on power MOSFETs.

Bias Effects on Total Dose-Induced Degradation of Bipolar Linear Microcircuits for Switched Dose-Rate Irradiation

Accelerated test techniques are needed in order to qualify bipolar devices intended for use in low dose rate environments. Indeed, low dose rate is known to enhance degradation of bipolar devices. Moreover, the bias of microcircuits is known to play a significant role in device degradation. In this work, bipolar microcircuits are irradiated with different bias configurations during the irradiation. It is shown that the bias configuration leading to the worst-case degradation is dose-rate dependent. Moreover, if a time-saving evaluation technique based on dose-rate switching is to be used, the effect of bias has to be investigated. In this work, this time-saving technique, the switched dose-rate technique, is applied for the first time to evaluate the behavior of dynamics parameters of a bipolar IC irradiated all pins grounded, and also to evaluate the behavior of static and dynamics parameters of bipolar ICs irradiated under several bias configurations. Good agreement is found between the predictive curve obtained with the switched dose-rate technique and the low dose rate data.