Single-Event Effects (SEE) Testing Bootcamp at the
Texas A&M University (TAMU) Cyclotron Institute
Module 03: Basic SEE & Test Execution
Definitions
Megan Casey
NASA Goddard Space Flight Center
1
Rob Davies
Jet Propulsion Laboratory
To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
TYPES OF SEES
2To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Radiation Effects on EEE Parts: Single Event Effects (SEE)
Permanent? Name DescriptionN
on
-destr
uctive
“Soft”
Err
or
SEU Single Event Upset Bi-stable circuit element, e.g. memory cell, flips state due to
charge pulse
SEFI Single Event Functional Interrupt An SEU that occurs in a control register thereby changing
the operating characteristics of a microcircuit
SET Single Event Transient Spurious pulses in analog circuitry
Destr
uctive
“Hard
” E
rror
SEL Single Event Latchup High current state caused by ion turning on a parasitic
structure in a microcircuit. Clears only through power cycle.
SEB Single Event Burnout High current state in power transistors, diodes.
SEGR Single Event Gate Rupture Breakdown of the gate oxide of power MOSFET due to a
single ion strike.
SEDR Single Event Dielectric Rupture Large current through a dielectric driven by the voltage
across the dielectric. Caused by ion passage temporarily
lowering resistance of the dielectric.
3To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Types of SEE
• What are single-event effects (SEEs)?
o Any measurable or observable change in state or performance of a microelectronicdevice, component, subsystem, or system (digital or analog) resulting from a singleenergetic-particle strike.
• Types of SEEs include:
o SET – Transient
o SEU – Upset
o SEFI – Functional Interrupt
o SEL – Latchup
o SEB – Burnout
o SEGR – Gate Rupture
o SEDR – Dielectric Rupture
To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.4
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Radiation Effects on EEE Parts: Single Event Effects (SEE)
5
Non-destructive SEEs Destructive SEEs
SET SEU SEFI SEL SEB SEGR SEDR
Memories
Logic (Latches)
Logic (Combinational)
Microprocessors
Analog or Mixed Signal
Circuits
Photonics
FPGAs
ASICs
Power MOSFETs
Other Power Devices
Converters
Adapted from “DOT/FAA/TC-15/62: Single Event Effects Mitigation Techniques Report”
https://www.faa.gov/aircraft/air_cert/design_approvals/air_software/media/TC-15-62.pdf
To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Nondestructive SEE – SET
• A momentary voltage excursion (voltage spike) at a node in an integrated circuit caused by a
single energetic-particle strike.
6To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Nondestructive SEE – SET
• When an ion strikes a circuit, energy is deposited in the material. As the incident particle passes
through the IC, it loses energy by interacting with the atoms that make up the IC.
Ei
EoTCAD simulations courtesy of Kaitlyn Ryder.
7To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Nondestructive SEE – SET
• This energy loss will result in the excitation of the electrons in the semiconductor.
± ±±
±±
±±
±±
TCAD simulations courtesy of Kaitlyn Ryder.
8To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Nondestructive SEE – SET
• These free carriers will transport through the semiconductor.
±± ±
±
±±
±±
±
TCAD simulations courtesy of Kaitlyn Ryder.
9To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Nondestructive SEE – SET
• If the event occurs within the sensitive volume, then a transient current pulse results on the
circuit node(s) attached to the SV. In general, more energy would imply a more severe effect.
TCAD simulations courtesy of Kaitlyn Ryder.
10To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Nondestructive SEE – SET
• As device sizes/technology/fabrication node decrease, the number of sensitive
nodes/transistors that may collect charge from a single ion strike increases.
• Critical charge also decreases with device size. Decreased critical charge
results in increased SEE sensitivity, which results in increased single-event
error rates.Well ContactDrainSource
Gate
Figure adapted from DasGupta, M.S. Thesis,
Vanderbilt University, 2007
11To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Nondestructive SEE – SEU
• A soft error caused by the signal induced by a single energetic-particle strike.
• Worst-case test conditions for SEU are minimum operating voltage and
maximum clock frequency (if applicable).
E. P. Wilcox and M. J. Campola, "A TID and SEE Characterization of Multi-Terabit COTS 3D NAND
Flash," 2019 IEEE Radiation Effects Data Workshop, San Antonio, TX, USA, 2019, pp. 1-7.
12To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Nondestructive SEE – SEFI
• A soft error that causes the component to reset, lock-up, or otherwise
malfunction in a detectable way, but does not require power cycling of the
device (off and back on) to restore operability, unlike single-event latch-up
(SEL), or result in permanent damage as in single event burnout (SEB).
Transmitted Image Example of SEFI Example of SEFI
Figures from “Heavy Ion Test Report for the AD9364 RF Transceiver,”
https://nepp.nasa.gov/files/28554/NEPP-TR-2016-Chen-15-071-AD9364-T031716-TN44752.pdf
13To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Destructive SEE – SEL
• An abnormal high-current state in a device caused by the passage of a single
energetic particle through sensitive regions of the device structure and resulting in the
loss of device functionality.
• Worst-case test conditions for SEL are maximum operating voltage and maximum
operating temperature.
14To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Destructive SEE – SEL
• SEL may cause permanent damage to the device. If the device is not
permanently damaged, power cycling of the device (off and back on) is
necessary to restore normal operation.
• SEL in a CMOS device occurs when the passage of a single particle induces
the creation of parasitic bipolar (p-n-p-n) shorting power to ground.
15To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Destructive SEE – SEL
• For a variety of CMOS devices, high-current density conditions during SEL may
produce non-catastrophic, permanent interconnect damage from melting.
o SEL circumvention efforts should take this type of damage into account, especially since it
occurs over very short time periods and is difficult to observe without some form of surface
analysis.
• Small ejected metal spheres emerged as a signature for identifying this type of
damage.
16To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Destructive SEE – SEB• An event in which a single energetic-particle strike induces a localized high-current state in a
device that results in catastrophic failure.
• Worst case test conditions for SEGR are low operating temperatures. Room temperature is
usually considered acceptable.
• Typically, can be mitigated by a current-limiting resistor placed between the drain and power
supply during testing, but there is no way to mitigate in space
Quenched SEB Catastrophic SEB
Figures from “Recent Radiation Test Results for Trench Power MOSFETs,”
https://nepp.nasa.gov/files/28959/2017-Lauenstein-NSREC-Paper-DW-MOSFETs-TN44382.pdf
17To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Destructive SEE – SEGR
• An event in which a single energetic-particle strike results in a breakdown and subsequent
conducting path through the gate oxide of a MOSFET.
o An SEGR is manifested by an increase in gate leakage current and can result in either the
degradation or the complete failure of the device.
• Like SEB, the worst case test conditions for SEGR are low operating temperatures. Room
temperature is usually considered acceptable.
18To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Destructive SEE – SEDR
• Destructive rupture of any dielectric layer by a single ion strike. This
leads to leakage currents under bias and can be observed in power
MOSFETs, linear integrated circuits (with internal capacitors), or as
stuck bits in digital devices.
19To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
TYPES OF SEE TESTS
20To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Types of SEE Tests – Heavy Ion
• Can be used for both destructive and nondestructive SEE testing
o Different ions with different energies (and therefore LETs) allow for
generating cross-section curves that can be used to calculate upset rates
for a given radiation environment
• Terrestrial heavy ion SEE testing occurs in facilities with lower
energies than ions have in space
o Requires ensuring sufficient range of ions to reach sensitive volumes
o Deprocessing may be required. This may include:
» Delidding or decapsulating parts
» Thinning of devices
21To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Types of SEE Tests – Heavy Ion• Heavy ion facilities include:
o Texas A&M University Cyclotron Institute
o Lawrence Berkeley National Lab 88” Cyclotron
o Brookhaven National Lab Tandem Van de Graaff
o University of Jyväskylä RADiation Effects Facility (RADEF)
o Université Catholique de Louvain Heavy Ion Facility (HIF)
o Grand Accélérateur National d'Ions Lourds (GANIL)
• High energy heavy ion facilities include:
o NASA Space Radiation Lab at Brookhaven
o CERN High Energy Accelerator Mixed Field (CHARM)
22
22
To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Types of SEE Tests – Laser
• Can be used for both destructive and nondestructive SEE testing
• Laser SEE testing allows for precise identification of the locations of sensitive volumes
• There are typically two approaches to laser SEE testing: single photon absorption (front-side) and two photon absorption (back-side)
• TPA/back-side laser testing requires a highly polished substrate for the laser to penetrate through to the sensitive volumes
o High dopant concentrations can also reduce the laser penetration
• SPA/front-side laser testing can only be used on devices without heavy metal overfill
23To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Types of SEE Tests – Proton
• Can be used for both destructive and nondestructive SEE testing
• Can be used to bound heavy-ion SEE risk [Ladbury SEE 2017]
• Typically test with 100s of MeV protons for SEEs
Coverage from1E11 200 MeV protons/cm2 Coverage from1E7 heavy ions/cm2
24To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Types of SEE Tests – X-Rays
• Can be used for both destructive and non-
destructive SEE testing
• X-rays provide a pulsed, focused beam that
penetrates metallization and creates an ion
track similar to an ion
• Relatively new technique for SEE testing
• Interaction depends on atomic number (Z)
of target material and photon energy
o X-ray interacts with tightly bound electrons
25To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Types of SEE Tests – Neutron
• Can be used for destructive or non-destructive SEE testing
• Neutrons impinge on semiconductor devices and there is a
probability for a nuclear reaction to occur with the material in the
device.
o This nuclear reaction can produce one or more energetic charged particles
which can deposit energy (or charge) along its path until its energy is
depleted and it stops.
• There are two neutron sources at LANSCE: a high-energy neutron
source with energies from ~1 MeV to 600 MeV and a low-energy
neutron source that produces from sub-thermal neutrons to
approximately 1 MeV.
26To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Types of SEE Tests – Electron
• Electron SEE testing is very similar to proton SEE testing, but the mass of an electron is ~2000 times smaller.
• Smaller mass results in lower likelihood of generating secondary heavy ions (indirect ionization).
• It is only recently at the very small technology nodes that we are starting to observe low-energy-electron-induced SEEs from direct ionization.
• Natural space environments with heavy electron concentrations are Jupiter/Europa and the van Allen belts around the Earth
• Irradiating with electrons can cause a build up of electrons on test boards and cables/wires if not properly grounded or shielded. This build-up can result in shorting of the tested device/board.
27To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
TEST PLANNING
28To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Device Constraints
• Devices under test (DUTs) can range from very simple transistors to
the most complex systems on a chip (SOC)
o This range implies test set implementations can vary just as widely
• At the top level, the following are the key items to begin planning
with:
o Datasheet and
o Application requirements (mission specific or range for “generic” research)
• We note that implementing a test set hinges greatly on the DUT
type and requirements, however, detailed discussion of this is out of
scope for this talk.
29To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Device Complexity• Number of inputs/outputs
• Data rates
• Physical part/die size
• Flip-chip
• Roll angle (directionality of devices)
30To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Device Preparation
• Ion’s range of penetration is short compared to
packaging materials
o Cannot use protons for everything
• What is the package style and die material?
o Are there heat sinks?
• Methods: mechanical, chemical, and
electromagnetic (ablation lasers)
Open a can
XeF2 Si etch
M. R. Shaneyfelt, et al., SEE Symposium, 2011.
SOI SRAM
InGaP MMIC
16-bit DAC
31To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Test Setup – Boards
• On-board vs off-board data processing
• Real-time measurement vs post-processing
• Distance from equipment
• Distance from DUT
http://www.bnl.gov/medical/NASA/CAD/NSRL_Facility_and
_Target_Room.asp
Labyrinth is over
30 m long!
32To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Test Setup – Temperature• Sometimes you want to include temperature as a
variable in your test setup, and sometimes temperature is a consequence of your test design that still has to be considered
• Room temperature
o These are the most common tests and typically the easiest to implement
o Heatsinks and blower fans
» Simplest techniques for removing heat from high-currentor high-power devices
o Water coolant system
» Another technique for cooling high-current/power devices
o Forced air using dry nitrogen
• Cold temperature
o Dewar
» Requires access to liquid nitrogen and takes time to pump up/down
• High temperature
o Heaters are most often used for SEL testing
33To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Data Capture – Nondestructive SEEs
• How you capture the data is going to be determined by the kinds of SEEs you expect to observe:
o SETs typically are captured by an monitoring the output of interest on an oscilloscope
» This will provide information about transient duration (pulsewidth) and size (amplitude), as well as directionality (negative- or positive-going)
» There are also on- and off-chip circuits at the output that can be added to provide some SET information
o SEUs will often be simply counted post-irradiation (most common in memories), but may be captured with an oscilloscope (if the circuit is a latch chain or the output is clocked and read out)
o SEFIs often manifest as large numbers of SEUs in a single block/column/row, so the same techniques for data capture as SEU testing is required with additional back-end processing to parse addresses of upsets
» Supply voltages should also be monitored because SEFIs may also be accompanied by increased currents
34To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Data Capture – Destructive SEEs
• How you capture the data is going to be determined by the kinds of SEEs you
expect to observe:
o Generally, destructive SEEs are almost always identified by increases in current, so
monitoring the supplies is necessary.
o If a mitigation circuit is employed, the ability to “raise a flag” to identify when an
SEL/SEB/SEGR has occurred is necessary. Then, the number of times the flag has been
raised can be counted to calculate SEE rates.
35To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Data Capture – Statistics
• Data should be reproducible, so good statistics are necessary
• To ensure good statistics, these are some conditions that should be considered:
o Number of test devices
» This is especially critical for destructive SEE testing
» Part cost, beam time cost can also impact the number of devices that can be tested
o Error bars
» Few SEEs at a given LET result in large error bars, while high numbers of SEEs result in small error bars. Large error bars are commonly observed in low probability events, such as near the threshold LET. These are broadly referred to as counting statistics.
• Error can also be introduced through other sources, including beam start/stop, flux, spot size/uniformity, dead time, straggling/degrader, …
36To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Requirements – Dual and Competing Nature(s)
• Programmatic
o Cost
o Schedule
o Personnel
o Availability
o Criticality
o RISK!
• Technical
o Device
o Packaging
o Beam/facility
o Application
o Data Capture
Dual Nature 2: Flight Project versus ResearchHow we plan and prepare for a test will also vary with this trade space
All tests are driven by requirements and objectives in one manner or another
37To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Flight Project Requirements
• When planning a test for a flight project, considerations may include:
o Acceptance criteria
» Error or fail rate (System or Device)
» Minimum device hardness level
» Error definition and application information
o User application(s)
» Circuit
» Criticality
o Programmatic constraints
• The bottom line is that flight project tests are usually application specific and designed to get a specific answer, such as:
o Is the SEL threshold higher than X?
o Will I see an effect more than once every 10 days?
38To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Research Requirements
• These are less specific than requirements for flight projects and may include
o Generic technology/device hardness
o Application range
o Angular exploration
o Frequency exploration
o Beam characteristics such as ion/energy/range effects
o Error propagation, charge sharing, etc…
o Programmatic constraints
• The bottom line is that all requirements and objectives should be “in plan”, i.e., considered prior to test and included in test plan development.
39To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Test Set Requirements
• Test set requirements are a set of derived requirements from the mission/DUT/facility requirements
o Example: requirement for a test in vacuum may be different than one in air
• Knowing how a DUT performs is one thing, but defining requirements for a test system is clearly separate
o Test set requirements should encompass actual application range or have sufficient flexibility such that modifications can be made on site easily
• Mission Requirements generally have ranges of operation.
o The test set should accommodate this range in areas such as:
» Min, max, and typical (speed, temperature, voltage)
» Vary inputs
» Note the difference between static tests and dynamic tests
» Output loading
• We note that a test plan should provide full details, schematics, figures, photos, etc. of test method/set
40To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.
Speakers: Megan Casey, GSFC; Rob Davies, JPL
Generic vs. Specific SEE Testing
• Lot-specific
o Manufacturing changes
o Multiple fabrication facilities
• Application-specific
o Feedback resistors/capacitors result in timeconstants that could affect duration of transients
o Bias voltages, load currents/resistances, etc., couldchange results
o Generic data is more broadly applicable to futureapplications, but may not be the most realistic
o Mitigation techniques should also be tested if beingused during flight
41To be presented by Megan Casey at the Radiation Effects Bootcamp,
virtual event, Texas A&M University, March 15-18, 2021.