Thermal Neutron-Induced SEUs in the LHC Accelerator Environment

Matteo Cecchetto,Oliver Stein,Carlo Cazzaniga,Frederic Wrobel,Cristina Bahamonde Castro,Matteo Brucoli,Marta Bagatin,Alessandro Paccagnella,Luigi Esposito,Giuseppe Lerner,Kacper Bilko,Ruben Garcia Alia,Maris Tali,Salvatore Danzeca,Simone Gerardin,Yacine Kadi

doi:10.1109/tns.2020.2997992

Abstract

In addition to high-energy hadrons, which include neutrons, protons, and pions above 20 MeV, thermal neutrons (ThNs) are a major concern in terms of soft error rate (SER) for electronics operating in the large hadron collider (LHC) accelerator at the European Organization for Nuclear Research (CERN). Most of the electronic devices still contain Boron-10 inside their structure, which makes them sensitive to ThNs. The LHC radiation environment in different tunnel and shielded areas is analyzed through measurements and FLUKA simulations, showing that the ThN fluence can be considerably higher than the high-energy one, up to a factor of 50. State-of-the-art commercial-off-the-shelf (COTS) components such as SRAM, field-programmable gate arrays (FPGA), and Flash memories of different technologies are studied to derive the expected single-event upset (SEU) rate due to ThNs, relative to the high-energy hadron contribution. We find that for the studied parts and most of the accelerator applications, ThNs are the dominating source of upsets with respect to the high energy particles yielding even to neglect the latter in some cases. Indeed, they can induce, in electronics, up to more than 90% of the total upsets. The estimation is performed also for ground-level and avionic applications, and although in general, ThNs are not the main source of SER, in Flash memories they can play the same role as high energy neutrons. Related radiation hardness assurance (RHA) considerations for the qualification of components and systems against ThNs are presented.

Highlights

S INGLE-EVENT upsets (SEUs) in electronic devices to be installed in the complex of the large hadron collider (LHC) accelerator are typically associated with highly energetic particles, whereas as will be outlined in this article, thermal neutrons (ThNs) can play an equal or even dominant role for certain locations and components
The presence of 10B has been avoided in recent technologies with the removal of Borophosphosilicate glass (BPSG), it is still present inside the electronic devices as p-doping and near the back end of line (BEOL) structure as tungsten coating for the plugs connecting the drain to the copper layers [2]–[4]
The HEH cross sections can be obtained in different manners, with monoenergetic neutron/proton beams [at the Paul Scherrer Institut (PSI), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), and RADiation Effects Facility (RADEF)] or with a broad energy spectrum (CHARM and Chip Irradiation (ChipIr))

Summary

Introduction

S INGLE-EVENT upsets (SEUs) in electronic devices to be installed in the complex of the large hadron collider (LHC) accelerator are typically associated with highly energetic particles, whereas as will be outlined in this article, thermal neutrons (ThNs) can play an equal or even dominant role for certain locations and components. The presence of 10B has been avoided in recent technologies with the removal of Borophosphosilicate glass (BPSG), it is still present inside the electronic devices as p-doping and near the back end of line (BEOL) structure as tungsten coating for the plugs connecting the drain to the copper layers [2]–[4]. These atoms of 10B originate from the B2H6 etcher gas used to improve the adhesion of tungsten in the trench contacts [5], [6]. The critical charge to trigger upsets has decreased and, when lowering the supply

Objectives

Results

Conclusion