Predicting the low-dose-rate degradation of bipolar technologies is one of the main issues for circuits intended for use in the ionizing-radiation environment of space because of the enhanced low-dose-rate sensitivity (ELDRS). In this letter, ELDRS is shown to be related to competition between trapping and recombination of radiation-induced carriers in the oxide. The presented model is shown to be in good agreement with experimental data. It is also shown that this effect is strongly dependent on the oxide quality.

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Expérience GANIL/IRRSU

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We have investigated material susceptibilities to atmospheric neutrons by calculating nuclear cross sections for every natural element from carbon to bismuth. The alpha emitters that can be present in microelectronic devices have also been identified. To improve the performance of microelectronic devices, the semiconductor industry has introduced a number of chemical elements in the device process. These elements experience a natural flux of neutrons and can also contain natural radioactive isotopes. In both cases, device reliability can be compromised. We show that, at ground level, the introduction of an element may be more important than the effect of neutrons.

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Soft error mitigation schemes inherently lead to penalties in terms of area usage, power consumption and/or performance metrics. This work provides a radiation hardening efficiency analysis of two possible selective node hardening based on standard cells: Gate Sizing and Transistor Stacking. The impact on the Single-Event Transient cross-section, layout area and leakage current is discussed. The results indicate that both techniques provide the same area overhead and high efficiency for low particle linear energy transfer. Further, although transistor stacking exhibits lower static power consumption, gate sizing still presents the best trade-off between area, performance and reliability.

Thin silicon oxide layers on silicon substrates are investigated by scanning probe microscopy before and after irradiation with 210 MeV Au+ ions. After irradiation and complete chemical etching of the silicon oxide layer, silicon bumps grown on the silicon surface are observed. It is shown that each impinging ion induces one silicon bump at the interface. This observation is consistent with the thermal spike theory. Ion energy loss is transferred to the oxide and induces local melting. Silicon-bump formation is favored when the oxide and oxide-silicon interface are silicon rich.