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Abstract: We irradiated commercial SRAMs with wide-spectrum neutrons at different temperatures. We observed that, depending on the vendor, the soft error rate either increases or slightly decreases with temperature, even in devices belonging to the same technology node. SPICE simulations were used to investigate the temperature dependence of the cell feedback time and restoring current. The shape and magnitude of the particle-induced transient current is discussed as a function of temperature. The variability in the response is attributed to the balance of contrasting factors, such as cell speed reduction and increased diffusion with increasing temperature. [Copyright &y& Elsevier]

Abstract: We studied the impact of previous X-ray irradiation on the sensitivity of floating gate cells to heavy-ion upsets, to emulate the concurrent occurrence of both total ionizing dose and single event effects in the space environment. An increasing heavy-ion upset cross section for increasing total dose was measured, especially with low-LET particles, where the enhancement can be bigger than one order of magnitude. We attributed this behaviour to the combination of the threshold voltage shifts induced by X-rays and heavy ions. [Copyright &y& Elsevier]

Abstract: Besides being widely used in virtually all terrestrial applications requiring non-volatile storage, Flash memories are arousing increasing interest with regards to space applications. This work presents new original data on the occurrence of destructive events and supply current spikes in NAND Flash memories exposed to heavy ions. Interestingly enough, these phenomena occur irradiating the devices even in stand-by mode. We examined the dependence of these effects on Linear Energy Transfer (LET) and flux of impinging ions, we used different test protocols, and shielded different blocks of the memory. Our analysis shows that the permanent loss of functionality occurs only with high-LET ions and usually with high particle flux, originating from damage to the charge pumps, likely due to Single Event Gate Rupture. We also show that there is not necessarily a correlation between irreversible damage and supply current spikes, as previously believed, even though they both originate in the charge pump circuitry. [Copyright &y& Elsevier]

Robustness of InAlN/GaN devices under proton radiation is investigated. Several proton fluences ranging from 1 × 10 14 to 4 × 10 14 have been considered on two typologies of devices. Displacement damage is found to be the major responsible of device DC degradation leading to threshold voltage positive shift, ON resistance increase and drain current decrease, in all cases well correlated with proton fluence. Negligible difference is noticed in displacement damage effects measured on different device typologies. Furthermore, device geometry does not influence the impact of proton radiation on main DC parameters, either if gate width or length are considered. Radiation significantly affects trapping properties. A good correlation between the so-called current collapse increase and proton fluence is demonstrated when a high gate drain voltage value is imposed as trapping condition. Moreover radiation enhances the contribution of dynamic ON resistance and transconductance peak variation on current collapse increase. [ABSTRACT FROM AUTHOR]