The temperature dependence of single event upset （SEU） measurement both in commercial bulk and silicon on insulator （SOI） static random access memories （SRAMs） has been investigated by experiment in the Heavy Ion Research Facility in Lanzhou （HIRFL）. For commercial bulk SRAM, the SEU cross section measured by 12C ions is very sensitive to the temperature. The temperature test of SEU in SOl SRAM was conducted by 209Bi and 12C ions, respectively, and the SEU cross sections display a remarkable growth with the elevated temperature for 12C ions but keep constant for 209Bi ions. The impact of temperature on SEU measurement was analyzed by Monte Carlo simulation. It is revealed that the SEU cross section is significantly affected by the temperature around the threshold linear energy transfer of SEU occurrence. As the SEU occurrence approaches saturation, the SEU cross section gradually exhibits less temperature dependency. Based on this result, the experimental data measured in HIRFL was analyzed, and then a reasonable method of predicting the on-orbit SEU rate was proposed.
Monte Carlo simulations reveal considerable straggling of energy loss by the same ions with the same energy in fully-depleted silicon-on-insulator （FDSOI） devices with ultra-thin sensitive silicon layers down to 2.5 rim. The absolute straggling of deposited energy decreases with decreasing thickness of the active silicon layer. While the relative straggling increases gradually with decreasing thickness of silicon films and exhibits a sharp rise as the thickness of the silicon film descends below a threshold value of 50 nm, with the dispersion of deposited energy ascending above ~10%. Ion species and energy dependence of the energy-loss straggling are also investigated. For a given beam, the dispersion of deposited energy results in large uncertainty on the actual linear energy transfer （LET） of incident ions, and thus single event effect （SEE） responses, which pose great challenges for traditional error rate prediction methods.
Nano-scale Hf/HfO2-based resistive random-access-memory （RRAM） devices were fabricated. The cross-over between top and bottom electrodes of RRAM forms the metal-insulator-metal sandwich structure. The electrical responses of RRAM are studied in detail, including forming process, SET process and RESET process. The correlations between SET voltage and RESET voltage, high resistance state and low resistance state are dis- cussed. The electrical characteristics of RRAM are in a strong relationship with the compliance current in the SET process. The conduction mechanism ofnano-scale Hf/HfO2-based RRAM can be explained by the quantum point contact model.
Experimental evidence is presented showing obvious azimuthal dependence of single event upsets(SEU) and multiple-bit upset(MBU) patterns in radiation hardened by design(RHBD) and MBU-sensitive static random access memories(SRAMs), due to the anisotropic device layouts. Depending on the test devices, a discrepancy from 24.5% to 50% in the SEU cross sections of dual interlock cell(DICE) SRAMs is shown between two perpendicular ion azimuths under the same tilt angle. Significant angular dependence of the SEU data in this kind of design is also observed, which does not fit the inverse-cosine law in the effective LET method. Ion trajectory-oriented MBU patterns are identified, which is also affected by the topological distribution of sensitive volumes. Due to that the sensitive volumes are periodically isolated by the BL/BLB contacts along the Y-axis direction, double-bit upsets along the X-axis become the predominant configuration under normal incidence.Predominant triple-bit upset and quadruple-bit upset patterns are the same under different ion azimuths(Lshaped and square-shaped configurations, respectively). Those results suggest that traditional RPP/IRPP model should be promoted to consider the azimuthal and angular dependence of single event effects in certain designs.During earth-based evaluation of SEE sensitivity, worst case beam direction, i.e., the worst case response, should be revealed to avoid underestimation of the on-orbit error rate.
We predict proton single event effect(SEE)error rates for the VATA160 ASIC chip on the Dark Matter Particle Explorer(DAMPE) to evaluate its radiation tolerance.Lacking proton test facilities,we built a Monte Carlo simulation tool named PRESTAGE to calculate the proton SEE cross-sections.PRESTAGE is based on the particle transport toolkit Geant4.It adopts a location-dependent strategy to derive the SEE sensitivity of the device from heavy-ion test data,which have been measured at the HI-13 tandem accelerator of the China Institute of Atomic Energy and the heavy-ion research facility in Lanzhou.The AP-8,SOLPRO,and August 1972 worst-case models are used to predict the average and peak proton fluxes on the DAMPE orbit.Calculation results show that the averaged proton SEE error rate for the VATA160 chip is approximately 2.17×10^(-5)/device/day.Worst-case error rates for the Van Allen belts and solar energetic particle events are 1-3 orders of magnitude higher than the averaged error rate.
Kai XiDi JiangShan-Shan GaoJie KongHong-Yun ZhaoHai-Bo YangTian-Qi LiuBin WangBing YeJie Liu
