0000000000493834
AUTHOR
M. Bonanomi
Neutron-induced soft errors in advanced Flash memories
Atmospheric neutrons are a known source of Soft Errors (SE), in static and dynamic CMOS memories. This paper shows for the first time that atmospheric neutrons are able to induce SE in Flash memories as well. Detailed experimental results provide an explanation linking the Floating Gate (FG) cell SE rate to the physics of the neutron-matter interaction. The neutron sensitivity is expected to increase with the number of bits per cell and the reduction of the feature size, but the SE issue is within the limit of current ECC capabilities and will remain so in the foreseeable future.
Traces of errors due to single ion in floating gate memories
Single, high energy, high LET, ions impacting on a Floating gate array at grazing or near-grazing angles lead to the creation of long traces of FGs with corrupted information. Every time a FG is crossed by a single ion, it experiences a charge loss which permanently degrades the stored information. If the ion crosses more than one FG, the threshold voltage of all those FGs interested by its track will be degraded.
Can Atmospheric Neutrons Induce Soft Errors in NAND Floating Gate Memories?
Atmospheric neutrons can interact with the matter inside a microelectronic chip and generate ionizing particles, which in turn can change the state of one or more memory bits [soft error (SE)]. In this letter, we show that SEs are possible in Flash memories, although with extremely low probabilities. While this problem will increase for future technologies, we do not expect SEs to be the reliability limiting factor for further floating gate scaling.
Effect of Ion Energy on Charge Loss From Floating Gate Memories
Heavy ions typical of the space environment have energies which exceed by orders of magnitude those available at particle accelerators. In this paper we are irradiating state of the art floating gate memories by using both a medium energy (SIRAD) and a high energy (RADEF) facilities. The corruption of stored information decreases when increasing ion energy. The proposed model deals with the broader track found for higher energy ions. Implications for testing procedures and for reliability considerations are discussed.