Space Radiation Effects in Electronic Components.

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Space Radiation Effectsin Electronic Components.

• Len Adams
• Professor Associate, Brunel Univ.
• Consultant to Spur Electron.
• For PA and Safety Office.
• May 2003

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Space Radiation Effects in Electronic
ComponentsStructure of Presentation

• Space radiation environment
• Radiation effects in electronic components.
• Radiation testing
• Use of commercial components
• Guide to comrad-uk resource
• Open discussion

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Space Radiation EnvironmentOverview

• Complex and Dynamic
• Trapped Radiation Belts of energetic
  electrons and protons
• Cosmic Rays (Energetic Ions)
• Solar Event protons

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Space Radiation EnvironmentTrapped Radiation

• Electrons and Protons are trapped in the Earths
  magnetic field, forming the Van Allen belts.
• Electrons up to 7 MeV
• Protons up to a few hundred MeV.

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Electron Belts
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Proton Belts
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Space Radiation EnvironmentTransiting Radiation

• Very high energy Galactic Cosmic Rays originating
  from outside the solar system
• Solar Events. (X-rays, protons and heavy ions)

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Space Radiation EnvironmentGalactic Cosmic Rays

• 85 Protons, 14 Alpha particles, 1 Heavy
  Nuclei.
• Energies up to GeV
• Expressed in terms of Linear Energy Transfer
  (LET) for radiation effects purposes

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Space Radiation EnvironmentSolar Flares

• Occur mostly near first and last year of solar
  maximum
• Solar Events, composed mainly of protons with
  minor constituent of alpha particles, heavy ions
  and electrons

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Space Radiation EnvironmentSouth Atlantic Anomaly

• Distortion of the earths magnetic field allows
  the proton belts to extend to very low altitudes
  in the region of South America
• Low Earth Orbiting satellites will be exposed to
  high energy protons in this region

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Space Station. 1 year dose-depth curve.
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Space Station . Non-Ionizing Energy Loss
spectrum.
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Space Station. Orbit averaged LET spectra
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Space Station. Proton flux as a function of
orbital time.
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Radiation Effects in Components(1) IONIZATION

• Mechanism Charge generation, trapping and
  build-up in insulating layers.
• Due to Electrons, Protons.
• Main Effects Parameter drift. Increased leakage
  currents. Loss of noise immunity. Eventual
  functional failure

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Radiation Effects in Components(2) DISPLACEMENT
DAMAGE

• Mechanism Disruption of crystal lattice
• Due to Protons
• Main Effects Reduced gain, increased ON
  resistance, reduced LED output, reduced charge
  transfer efficiency in CCDs.

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Radiation Effects in Components(3) SINGLE EVENT

• Mechanism Dense path of localised ionization
  from a single particle hit
• Due to Cosmic rays, high energy protons.
• Main Effects Transient current pulses, variety
  of transient and permanent Single Event Effects

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Single Event Current Pulse
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SEU Mechanism in CMOS bistable
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Radiation Effects in Components(4) Single Event
Effects in detail

• Latch-up. Permanent, potentially destructive
• Bit flips (Single Event Upset) in bistables
• High Anomalous Current (HAC), snap-back
• Heavy Ion Induced Burn-out in power MOS
• Single Event Gate Rupture (SEGR)
• Single Event Transient, noise pulses, false
  outputs
• Soft Latch (device or system lock up)

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Typical Single Event Transient Requirements.

• Output voltage swing of rail voltage to ground
  and ground to rail voltage.
• Duration
• 15 microseconds for Op-Amps.
• 10 microseconds for comparators, voltage
  regulators and voltage references.
• 100 nanoseconds for opto-couplers.

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Radiation TestingSpecifications and Standards

• Total Ionizing Dose
• SCC-22900 (ESA-SCC)
• Mil Std 883E Method 1019.6 (DESC)
• ASTM F1892 (includes ELDRS)
• Single Event
• SCC-29500 (ESA-SCC)
• EIA/JEDEC Standard EIA/JESD57
• ASTM F1192

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Radiation TestingImportant Considerations

• Choice of radiation source.
• Specifications and Standards
• Worst case or application bias
• Test software
• Number of samples
• Traceability
• Databasing

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Radiation TestingChoice of Source

• Total Ionizing Dose Co-60 gamma or
• 1-3 MeV electrons (Linac or VdG)
• Displacement Damage Protons (10-20 MeV),
  Neutrons (1 MeV), Electrons (3-5 MeV)
• Single Event Heavy Ion Accelerator (ESA-Louvain
  HIF), Proton Accelerator (ESA-PSI PIF)
• Cf-252 CASE laboratory system.

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Typical Radiation Verification (RVT) requirements.
TECHNOLOGY REQUIREMENT DOSE RATE
Bipolar Transistor Data gt 10 yrs High or Low
MOS Transistor All diffusion lots High or Low
Linear ICs All diffusion lots Low
MOS Digital ICs Data gt 1 yr High or Low
Bipolar Digital ICs Data gt 10 yrs Low
ASICs, FPGA. Data gt 2 yrs Low
MOS RAM, ROM Data gt 2 yrs High or Low
Bipolar RAM, ROM Data gt 6 yrs Low
Optoelectronics All diffusion lots High or Low
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Technologies generally considered to be radiation
tolerant ( 300 krad)

• Diodes (other than zener).
• TTL logic (e.g. 54xx series).
• ECL (Emitter Coupled Logic).
• GaAs (Gallium Arsenide) technologies.
• Microwave devices.
• Crystals.
• Most passives.

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Radiation TestingSample Size/Traceability

• Sample Size
• Total Ionizing Dose. Minimum 5 samples. 4 test,
  1 reference.
• Single Event. 3 samples recommended.
• Traceability
• Use single Lot-Date-Code for test and flight
  hardware.

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Dose-rates for testing.

• - High Dose Rate
• SCC 22900 Window 1. 1-10 rads/sec.
• MIL883E 1019.6. 50-300 rads/sec.
• Low Dose Rate
• SCC 22900 Window 2. 0.01-0.1 rads/sec.
• MIL883E 1019.6. 0.01 rads/sec.
• Elevated Temp. 0.5-5 rads/sec.

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Radiation TestingTest Software (Single Event)

• Test pattern dependence. All 1, All 0, Alternate
  1-0, Chequerboard, MOVI.
• Different sensitivities for different registers.
• Dead Time. (detect flip/record/rewrite)
• How to test Processors (Golden Chip ?)
• Possibility to run application software ?
• Beware of software/hardware interaction.

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Radiation TestingAnd finally

• TEST IT LIKE YOU FLY IT
• FLY IT LIKE YOU TEST IT
• (Ken LaBel. GSFC)

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Use of Commercial Components

• The use of commercial technology does NOT
  necessarily result in cost-saving.
• Cost of Ownership is the important consideration.
• First choice should always be QML or Space
  Quality components if available.

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Why Use Commercial Technology ?

• Complexity of functions
• Performance
• Availability (limited number of QML/Space
  suppliers).

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What are the drawbacks of commercial technology?

• Little or no traceability
• Rapid and unannounced design and process changes.
• Rapid obsolescence
• Packaging Issues (Plastic).
• - Effect of burn-in on radiation response
• - Deep dielectric charging in space (?)

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COTS Hardness Assurance

• Define the hazard
• Evaluate the hazard
• Define requirements
• Evaluate device usage
• Discuss with designers
• Iterate process as necessary

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Risk Assessment Mitigation

• Components list review by a radiation expert
• Good Radiation Design Margin (2-5)
• Fully characterise key components
• Limit the use of new technologies
• Eliminate or shield marginal technologies
• Maintain awareness of developments in radiation
  effects
• Do not cut back on testing
• Look for system solutions

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Countermeasures/MitigationTotal Ionizing Dose.

• Additional shielding. Only effective in electron
  dominated environments.
• Cold redundancy (sparing). Not effective for
  all technologies.
• Generous derating.
• Robust electronic design. High drive currents,
  low fan-out or loading. Large gain margins, high
  noise immunity etc.

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Countermeasures/Mitigation. Single Event Effects

• Note that additional shielding is NOT effective.
• Ensure systems are not sensitive to transient
  effects.
• Use fault tolerant design techniques.
• Use Error Detection and Correction for critical
  circuits.
• Ensure systems can re-boot autonomously.

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COMRAD-UKAn integrated Web resource of
components radiation effects data.
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Why Integrated Web Resource ?

• COMRAD provides more than a database.
• it includes
• Components radiation effects database.
• A tutorial handbook.
• Links to radiation effects sites.
• Links to manufacturers sites.
• Links to publications in .pdf format.
• Experts Forum for technical discussions.

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Available from COMRAD-UK Home Page
Terms Links Glossary
Index Search Total Dose
Heavy Ion Neutron Proton
Sponsors Manufacturers Seminars
Handbook Publications News Experts Forum
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(No Transcript)
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Origins of COMRAD-UK Database

• ESA RADFX (on discs)
• Database Round Table (RADECS 1993)
• Discussions with Space Agencies, Scientific
  Institutes and Industry
• Discussions with CERN LHC Project and Detector
  groups.

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Aims of COMRAD-UK Database

• To be informative not regulatory.
• To contain recent data and be continuously
  updated.
• To provide data summary and detailed tabulated
  data (if available).
• To provide contact details for the test
  authority.
• To be expandable for High-Energy Physics and
  Avionics

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COMRAD-UK Database status.

• 700 Total Dose records
• 280 Single Event Records
• Being updated on a monthly basis
• Primary data resources
• IEEE NSREC Data Workshop and Proceedings
• RADECS Data Workshop and Proceedings
• ESA Contract Reports.
• IEEE Publications.
• CERN reports and publications

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Origins of COMRAD-UK Handbook

• ESA Radiation Design Handbook. PSS-609
• Handbook of Radiation Effects. OUP 1993.
• The use of commercial components in aerospace
  technology. BNSC Contract Report 1999.
• Participation in CERN RD-49 collaboration.
  Hardened microelectronics and commercial
  components.
• Various international seminars and workshops over
  past 5 years.

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Aims of COMRAD-UK Handbook

• A brief (100 page) tutorial guide to the space
  application of components.
• To assist in the assessment of components in the
  COMRAD database for any particular mission.
• Provides guidance on Hardness Assurance
  practices.
• Discusses the application of commercial
  components.

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Handbook Contents

• The Space Radiation Environment
• Radiation Effects Prediction Techniques
• Radiation Effects in Electronic Components
• Designing Tolerant Systems
• Radiation Effects Databases
• Radiation Testing
• Hardness Assurance Management
• Recommended Procurement Practices

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COMRAD-UKExperts Forum

• The Experts Forum allows users to post queries
  on the Web-site.
• These will, as far as possible, be answered by
  Spur Electron but it is also possible for other
  users to provide an input and start a discussion.

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Summary

• COMRAD-UK is a Web based integrated source of
  components radiation effects data.
• COMRAD-UK is co-sponsored by the British National
  Space Centre and maintained on their behalf by
  SPUR-Electron.
• The site is under continuous development
• - comments and suggestions are welcome.
• comrad-uk.net
• radinfo_at_spurelectron.com

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Hardness Assurance in the real world

• WE HAVENT GOT THE MONEY
• SO WEVE GOT TO THINK.
• (Lord Rutherford 1871-1937)