F. Wrobel

Simulation of nucleon-induced nuclear reactions in a simplified SRAM structure: scaling effects on SEU and MBU cross sections

Academic 128/spl times/128 bit structures are simulated to study soft error cross sections induced by high-energy nucleons (n/p) in SRAM memories. The distributions of secondary ions are obtained by the nuclear high energy transport code and analyzed in terms of energy deposited in the sensitive volume of each memory cell. Multiple-bit upset cross sections are compared to single-event upset cross sections, and trends associated with scaling effects are presented.

Criterion for SEU occurrence in SRAM deduced from circuit and device Simulations in case of neutron-induced SER

A reliable criterion for SEU occurrence simulation is presented. It expresses the relationship existing at threshold between the magnitude and duration of the ion-induced parasitic pulse. This criterion can be obtained by both three-dimensional device and SPICE simulations. Using this criterion, the simulated and experimental SER on 130 and 250 nm technologies are shown to be in good agreement.

Incidence of multi-particle events on soft error rates caused by n-Si nuclear reactions

Neutron reactions with silicon nuclei can be responsible for much of the soft errors rate (SER) observed, for instance, in high density memories. The nuclear reactions create ionizing particles that then can induce charge collection at sensitive nodes. In many cases, the nuclear reaction produces a shower of ions. Models for the prediction of SER are much more complicated if all the simultaneously created ions must be considered. In this paper, we examine the proportion of events in which a shower of particles is actually involved. Spallation reaction effects for incident neutrons in the 50-2000 MeV energy range are analyzed using a simple spherical structure. Calculations are performed using BRIC (B_ruyeres le Chatel I_ntra-nuclear C_ascade), an improved version of HETC (High Energy Transport Code). The results show that the proportion of events actually due to showers is less than 2% of the total number of SERs.

Contribution of SiO/sub 2/ in neutron-induced SEU in SRAMs

The aim of this work is to show the contribution of nuclear events occurring with oxygen nuclei in SRAM-oxide such as SiO/sub 2/ and emphasize that they are likely to increase the soft error rate by about several tens of percent. Recoil energies are calculated with a dedicated subroutine, which accounts for elastic and nonelastic reactions in the 5-150-MeV energy range. SEU cross sections are evaluated using the criterion of critical energy deposited in a cubic sensitive volume.

MC-ORACLE: A tool for predicting Soft Error Rate

Natural radiation is known to be a source of microelectronics failure. For instance, neutrons, protons, heavy ions, and alpha particles have all been implicated in the occurrence of soft errors in memory devices. To predict the reliability of electronics devices we developed a tool called MC-ORACLE. This Monte Carlo application is based on the common empirical soft error criterion for a critical charge deposited in a parallelepiped sensitive volume. MC-ORACLE is able to deal with complex structures composed of various materials. It provides single and multiple error cross sections as well as the soft error rate.

Monte-Carlo simulations to quantify neutron-induced multiple bit upsets in advanced SRAMs

This paper presents a new 3D methodology to simulate Multiple Bit Upsets in commercial SRAMs. Experiments are performed at the Los Alamos neutron facility on 90, 130, and 250 nm SRAMs and compared to Monte-Carlo simulations. A discussion on ions inducing MBUs is also proposed.

Dose rate effects in bipolar oxides : Competition between trap filling and recombination

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.

A review of DASIE code family: contribution to SEU/MBU understanding

DASIE (the detailed analysis of secondary ion effect) is the name of a code family dedicated to the SEE rate prediction. This paper presents a review of DASIE code family and its contributions to SEU (single event upset) and MBU (multiple bit upset) understanding.

Prediction of Multiple Cell Upset Induced by Heavy Ions in a 90 nm Bulk SRAM

The PHISco simulation tool was known to be able to predict the SEU cross section for incident ions. This tool is improved in this work to also predict the MCU rate. Experimental and predicted results are shown to be in good agreement on a 90 nm bulk SRAM. The simulated SRAM structure includes the N-well, which is known to be a barrier to the charge carriers.

Hafnium and Uranium Contributions to Soft Error Rate at Ground Level

Current technologies are sensitive to low Linear Energy Transfer particles such as alphas. These particles can be spontaneously produced by some radioactive elements, called alpha-emitters. Here, we investigate two examples of emitters, Hafnium and Uranium. By calculating the disintegration rate in a modern technology with hafnium dioxide, we show that hafnium has no incidence on Soft Error Rate. Moreover, from Monte Carlo simulations, we point out that natural Uranium concentration in a silicon wafer lead to a Soft Error Rate comparable to that due to neutrons at ground level.