The contribution of nuclear reactions to heavy ion single event upset cross-section measurements in a high-density SEU hardened SRAM

Abstract

Heavy ion irradiation was simulated using a Geant4 based Monte-Carlo transport code. Electronic and nuclear physics were used to generate statistical profiles of charge deposition in the sensitive volume of an SEU hardened SRAM. Simulation results show that materials external to the sensitive volume can affect the experimentally measured cross-section curve.

Sub-LET Threshold SEE Cross Section Dependency With Ion Energy

“…These events, product of nuclear reactions, are experimentally visible in the so-called sub-Linear Energy Transfer (LET) threshold region, in which the primary ions have LET values too low to induce SEEs through direct ionization. In fact, as was predicted through calculations in [2], [3] and measured inorbit in [4], the contribution from heavy ion induced nuclear reactions can be dominant (by over two orders of magnitude) for an interplanetary environment and a radiation hardened component with respect to the traditional, direct ionization based prediction methods.…”

Compact Modeling and Simulation of Heavy Ion Induced Soft Error Rate in Space Environment: Principles and Validation

“…The contribution to the SER of nuclear reactions below the threshold LETs makes the problem more difficult, necessitating the use of the Monte Carlo simulation-based approach [23,27,28]. Monte Carlo methods have also been used for the description of deviations from the isolated SV approximation [29].…”

“…The radiation-hardened memories are typically characterized by relatively high critical LETs when the contribution to SER from the subthreshold region C    must be accurately estimated. Particularly, such data with a pronounced subthreshold region in cross sections for 4 Mbit 0.25 µm RHBD SRAM's were presented in [23]. We have used in this case the full "logarithmic" form of the cross section approximation (7) to accurately interpolate the test data both in the above threshold and in the subthreshold regions.…”

“…9. Approximation of the cross section data (adapted from [23]) with equation (7) Bogorad et al [24] provided the results of the SER calculations and some on-orbit SER data for the same SRAMs. In-flight data [24] 1.8×10 -10 errors/bit/day A comparison between the IRPP calculations [24] and our compact simulations with the parameters in Fig.…”

Practicality of evaluating soft errors in commercial sub-90 nm CMOS for space applications

“…Most of the detailed soft error calculations that have been done to date -i.e., [10,28,[47][48][49] -rely on detailed technology information. This is often not available or affordable to obtain for standard commercial products.…”