Study of the Impact of the LHC Radiation Environments on the Synergistic Displacement Damage and Ionizing Dose Effect on Electronic Components

Analysis of Bipolar Integrated Circuit Degradation Mechanisms Against Combined TID–DD Effects

“…A first observation that can be made regarding the previously discussed TID data is that the higher degradation observed in the past with protons was certainly due to the difference in dose rate between the gamma and the proton experiment. Indeed, it can be seen that the degradation response obtained with the gamma source at an ionizing dose rate of 620 Gy(SiO2).h -1 is practically the same as the proton response showed in [3] where the current drops suddenly around a TID of 500 Gy(SiO2). This indicates that at this high ionizing dose rate, the TID degradation mechanisms seem to dominate over the DD ones at this DDD/TID ratio.…”

“…To gather more information on the internal degradation mechanisms, new irradiations against TID have been performed besides the one presented in our previous work [3]. During these irradiations, not only the output current was monitored but also the output current as a function of the voltage supply characteristic at different irradiation steps.…”

“…For instance, at CERN for radiation qualification purposes the Proton Irradiation Facility (PIF) of the Paul Scherrer Institute (PSI) is widely used. It provides proton energies ranging from 30 MeV up to 220 MeV, which corresponds to DDD/TID ratios ranging from 3 to 6  10 -4 , which is rather low compared to levels that have to be reached to be representative of the LHC environments [3], which are ranging from 10 -4 up to 10 -2 . Mixing different types of particles and energies would allow achieving values over the whole range, for instance, electrons allow to obtain ratios in the 10 -5 range while neutron facilities with strong gamma contributions allow reaching the 10 -3 range.…”

“…Then, using different test locations, targets, and shielding, the facility can achieve a wide range of DDD/TID ratios as shown in previous work [3]. Three different irradiations at different ratios indicated in Table II were performed to study the impact of combined TID-DD effects on the circuit response at different DDD/TID ratios.…”

“…In our previous work [3], the same approach was followed and a similar methodology to qualify components against combined TID-DD based on the assessment of the dependency between degradation or failure rate with the DD over TID rate ratio. An example of the application of this methodology was proposed with a bipolar IC whose observed changes in degradation profiles with different DDD/TID ratios were assumed to be due to degradation interactions at the internal circuit level.…”