Radiation Effects

Ionizing radiation can cause unwanted effects in semiconductor devices. Energetic Protons, Neutrons, Heavy Ions, and Alpha particles can strike sensitive regions of the transistor, causing various failures, or Single-Event Effects (SEE), such as:

• Single-Event Upsets (SEUs)
• Single-Event Transients (SETs)
• Single-Event Functional Interrupt (SEFI)

These terms and the failure modes they describe are explained in detail in the Conference Papers below. While SEUs, SETs, and SEFIs cannot be prevented, their effects in CMOS re-configurable logic devices can be mitigated (click on the Applications link on the left for mitigation information).

Characterizing Radiation Effects

Sensitivity to Radiation Effects is dependent on many factors, including transistor geometry and cell layout. Certain CMOS technologies, such as SRAM, are very sensitive to SEE. Other technologies, such as the CMOS Configuration Latch design used in Xilinx devices, are less sensitive to SEE.

To understand the sensitivities of a particular device, extensive radiation testing must be undertaken. In cooperation with the Single-Events Consortium, Xilinx tests all QPro™ FPGA and PROM devices at particle accelerators throughout the United States. Test results are analyzed and reported by experts in the SEE Consortium (more information about the SEE Consortium is available by clicking on the SEE Consortium link on the left).

Radiation Effects Conference Material

Detailed information about radiation effects in semiconductor devices is reported by a wide range of researchers at three main international conferences:

• The Nuclear Space Radiation Effects Conference (NSREC)
• The Military Applications of Programmable Logic Devices Conference
• The Radiation Effects on Components and Systems Organization Conference

Conference Papers

• "NSEU Sensitivity of SRAM-based FPGAs"

MAPLD 2003 Paper C5. Joe Fabula, Austin Lesea, Carl Carmichael, and Saar Drimer
Xilinx, Inc.
Abstract: fabula_a.html


• "Consequences and Categories of SRAM FPGA Configuration SEUs"

MAPLD 2003 Paper C6. Paul Graham(1), Michael Caffrey(1), Michael Wirthlin(2), Eric Johnson(2), and Nathan Rollins(2)
(1) Los Alamos National Laboratory
(2) Brigham Young University
Abstract: graham_a.pdf
Presentation: c6_graham_s.pdf
Paper: c6_graham_p.pdf


• "Single-Event Upsets in SRAM FPGAs"
  MAPLD 2002 Paper P8. "Single-Event Upsets in SRAM FPGAs"
  Michael Caffrey(1), Paul Graham(1), Eric Johnson(1), and Michael
  Wirthlin(2)
  (1) Los Alamos National Laboratory
  (2) BYU
  Abstract: caffrey1_a.pdf
  Presentation: p8_caffrey_s.pdf
  Paper: p8_caffrey_p.pdf
  
• "Total Ionizing Dose Performance of SRAM-based FPGAs and supporting PROMs"

MAPLD 2000 Paper C2. Joe Fabula and Howard Bogrow, Xilinx, Inc.
Abstract: Fabula_A.pdf
Presentation: C2_Fabula_S.pdf
Paper: C2_Fabula_P.pdf


• "Radiation Test Results of the Virtex™ FPGA and ZBT SRAM for Space Based Reconfigurable Computing"

MAPLD 1999 Paper C2. Earl Fuller and Paul Caffrey, Los Alamos National Laboratory
Presentation: C2_Caffrey_Fuller_S.pdf
Paper: C2_Fuller_P.pdf
Abstract: caffrey.pdf


• "Radiation Tolerance of High-Density FPGAs"

MAPLD 1998 Paper B6. Peter Alfke and Rick Padovani, Xilinx, Inc.
Abstract: B6.htm
Paper: B6_Alfke.PDF


• "Neutron Single Event Upsets In SRAM-Based FPGAs"

NSREC 1998. Mattias Ohlsson(1), Peter Dyreklev(1), Karin Johansson(1), and Peter Alfke(2).
(1) Ericsson Saab Avionics AB
(2) Xilinx, Inc.
Paper: FPGA_NSREC98.pdf