T3.5 Substrate sensitivity to irradiation [M12-M30]

This task will evaluate the sensitivity of reference POI substrate (T3.1) as well as developed alternative substrates (T3.2) to the ionizing irradiation similar to what electronics experience when operating in space conditions. This point is a key feature to properly estimate the need for specific packaging conditions which will impact the complexity and the cost of the final product. Moreover, substrate optimization may be necessary as a trade-off between substrate performance and its radiation hardness may exist. One can think e.g., about optimization of porosification process (in terms of size, depth of pore, used chemicals and annealing steps) to reduce radiation-induced degradation (e.g., positive charge and interface states build-up during radiation). Predictive simulations of INC using radiation GEANT-4 simulator will allow to minimize shots and be more efficient. UCL will manage the radiation campaign at University Cyclotron facility (CRC). Total Ionizing Dose effect using both gamma-rays from Co-60 and protons will be studied. Furthermore 50 MeV protons will be used to study possible displacement damages (DD) on certain, the most promising materials. Following the specifications for 5G direct connectivity Satellite NGSO constellation at 600 km polar orbiting with life-time duration of 7 years and adding certain security margin, our radiation tests will consider reaching ~20 krad (Si) for TID and 5e10 protons(50MeV)/cm2 for DD tests. The most promising materials will be pushed to a limit of 100krad TID test. The same test vehicle developed in T3.1 will be used. Pre- and post-radiation tests will be realized to extract the degradation of the main device parameters as a result of oxide charge and interface state build-up, possible atom displacement, and hence carrier mobility, resistivity, ... degradations. Degradation of FoM will be correlated with degradation of basic material parameters (oxide charges, interface traps, ...) and with predictive GEANT-4 simulations by INC. This will allow to get an insight into radiation mechanisms responsible for the device/structure degradation, their particularities and further inclusion into predictive simulations/modelling. Reversibility of radiation-induced changes/degradation will be analysed. Obtained results will be benchmarked in T3.6.