ASTM F1262M-95(2002)
(Guide)Standard Guide for Transient Radiation Upset Threshold of Digital Integrated Circuits
Standard Guide for Transient Radiation Upset Threshold of Digital Integrated Circuits
SIGNIFICANCE AND USE
Digital logic circuits are used in system applications where they are exposed to pulses of radiation. It is important to know the minimum radiation level at which transient failures can be induced, since this affects system operation.
SCOPE
1.1 This guide is to assist experimenters in measuring the transient radiation upset threshold of silicon digital integrated circuits exposed to pulses of ionizing radiation greater than 103 Gy (Si)/s.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:F 1262M–95 (Reapproved 2002)
Standard Guide for
Transient Radiation Upset Threshold Testing of Digital
Integrated Circuits (Metric)
This standard is issued under the fixed designation F 1262M; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope mined by the logic signals at its inputs at the same time (except
for small time delays caused by the propagation delay of
1.1 This guide is to assist experimenters in measuring the
internal logic elements).
transient radiation upset threshold of silicon digital integrated
3.1.1.1 Discussion—Combinational circuits contain no in-
circuits exposed to pulses of ionizing radiation greater than 10
ternal storage elements. Hence, the output signals are not a
Gy (Si)/s.
functionofanysignalsthatoccurredatpasttimes.Examplesof
1.2 This standard does not purport to address all of the
combinational circuits include gates, adders, multiplexers and
safety concerns, if any, associated with its use. It is the
decoders.
responsibility of the user of this standard to establish appro-
3.1.2 complex circuit response mechanisms—For medium
priate safety and health practices and determine the applica-
scale integration (MSI) and higher devices it is useful to define
bility of regulatory limitations prior to use.
three different categories of devices in terms of their internal
2. Referenced Documents design and radiation response mechanisms.
3.1.3 over-stressed device—A device that has conducted
2.1 ASTM Standards:
more than the manufacturer’s specified maximum current, or
E 666 Practice for Calculating Absorbed Dose From
dissipated more than the manufacturer’s specified maximum
Gamma or X Radiation
power.
E 668 Practice for Application of Thermoluminescence-
3.1.3.1 Discussion—In this case the DUT is considered to
Dosimetry(TLD)SystemsforDeterminingAbsorbedDose
be overstressed even if it still meets all of the manufacturer’s
in Radiation-Hardness Testing of Electronic Devices
specifications. Because of the overstress, the device should be
F 867M Guide for Ionizing Radiation Effects (Total Dose in
evaluated before using it in any high reliability application.
Radiation-Hardness Testing of Electronic Devices
3.1.4 sequential logic—A digital logic system with the
2.2 Military Standards:
property that its output state at a given time depends on the
Method 1019 in MIL-STD-883. Steady-State Total Dose
sequence and time relationship of logic signals that were
Irradiation Procedure
previously applied to its inputs.
Method 1021 in MIL-STD-883. Dose Rate Threshold for
3.1.4.1 Discussion—Examples of sequential logic circuits
Upset of Digital Microcircuits.
include flip-flops, shift registers, counters, and arithmetic logic
3. Terminology
units.
3.1.5 state vector—A state vector completely specifies the
3.1 Definitions:
logic condition of all elements within a logic circuit.
3.1.1 combinational logic—A digital logic system with the
3.1.5.1 Discussion—For combinational circuits, the state
property that its output state at a given time is solely deter-
vector includes the logic signals that are applied to all inputs:
for sequential circuits, the state vector must also include the
This guide is under the jurisdiction of ASTM Committee F01 on Electronics
sequence and time relationship of all input signals. In this
and is the direct responsibility of Subcommittee F01.11 on Nuclear and Space
guide the output states will also be considered part of the state
Radiation Effects.
Current edition approved Dec. 10, 2002. Published May 2003. Originally vector definition. For example, an elementary 4-input NAND
approved in 1995. Last previous edition approved in 1995 as F 1262M – 95.
gate has 16 possible state vectors, 15 of which result in the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
same output condition (“1” state). A 4-bit counter has 16
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
possible output conditions, but many more state vectors be-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
cause of its dependence on the dynamic relationship of various
Discontinued. Replaced by F 1893. See 1997 Annual Book of ASTM Standards,
input signals.
Vol 10.04.
4 3.1.6 upset response—The electrical response of a circuit
Available from Standardization Documents Order Desk, Bldg. 4, Section D,
when it is exposed to a pulse of transient ionizing radiation.
700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F 1262M–95 (2002)
3.1.6.1 Discussion—Two types of upset response can occur: (12) Device temperature during test.
4.3 The state vectors in which the device is to be irradiated
(1) transient output error, for which the instantaneous output
are determined from the basic (see 8.2.1) and topological
voltage of an operating digital circuit is greater than a predetermined
analysis, (see 8.2.2) or both.
value (for a low output condition) or less than a predetermined value
(for a high output condition), and the circuit spontaneously recovers to
its pre-irradiation condition after the radiation pulse subsides. The
5. Significance and Use
predetermined values mentioned above are agreed to by all parties
5.1 Digital logic circuits are used in system applications
participating in the test and should be included in the test plan.
(2) stored logic state error, for which there is a change in the state
where they are exposed to pulses of radiation. It is important to
of one or more internal logic elements that does not recover spontane-
know the minimum radiation level at which transient failures
ously after the radiation pulse. Because the radiation changes the state
can be induced, since this affects system operation.
vector, the circuit spontaneously recovers to a different logic state.This
does not imply the change will always be immediately observable on a
6. Interferences
circuit output. However, the circuit can be restored to its original state
vector by re-initializing it afterwards.
6.1 Accumulated Ionizing Dose—Many devices may be
3.1.6.2 Discussion—Although the term upset response is
permanently damaged by the accumulated ionizing dose they
usually used to describe output voltage responses, some are exposed to during upset testing. This limits the number of
devices, such as open collector gates, are better characterized
radiation pulses that can be applied during transient upset
by measuring the output current. Upset response also includes testing. Accumulated ionizing dose sensitivity depends on
thetransientcurrentsthatareinducedinthepowersupplyleads
fabrication techniques and device technology. Metal oxide
(sometimes very large) as well as the response of the device semiconductor (MOS) devices are especially sensitive to
inputs, although in most applications the input response is not
accumulated ionizing dose damage. Newer bipolar devices
significant. with oxide-isolated sidewalls may also be affected by low
levels of accumulated ionizing dose. The maximum ionizing
4. Summary of Guide
dose to which devices are exposed must not exceed 10 % (see
4.1 Fortransientradiationupsetthresholdtests,thetransient
8.4.5) of the typical ionizing dose failure level of the specific
output voltage and the condition of internal storage elements,
part type.
or both, is measured at a succession of radiation levels to
6.2 Dosimetry Accuracy—Since this guide ultimately deter-
determine the radiation level for which transient voltage or
mines the dose rate at which upset occurs, dosimetry accuracy
functional test errors first occur. An oscilloscope, digital
inherently limits the accuracy of the guide.
storage oscilloscope, transient digitizer or similar instrument is
6.3 Latchup—Some types of integrated circuits may be
used to measure the output transient voltage. Functional tests
drivenintoalatchupconditionbytransientradiation.Iflatchup
are made immediately after irradiation to detect internal
occurs, the device will not function properly until power is
changesinstateinducedbytheradiation.Thedeviceisinitially
temporarily removed and reapplied. Permanent damage may
biased and set up in a predetermined condition. The test
also occur.Although latchup is an important transient response
conditions are determined from topological analyses or by
mechanism, this procedure is not applicable to latchup testing.
testing the device in all possible logic state combinations.
Functional testing after irradiation is required to detect internal
4.2 A number of factors are not defined in this guide and
changes of state, and this will also detect latchup.
must be agreed upon beforehand by the parties to the test.
6.4 Package Response—At dose rates above 10 Gy (Si)/s
These factors are described in the test plan.As a minimum the
the response may be dominated by the package response rather
test plan must specify the following:
than the response of the integrated circuit device being tested.
(1) Pulse width, energy spectrum, and type of radiation
For high speed devices, this may include lead/bondwire effects
source,
with upsets caused solely by the radiation pulse’s rise and fall
(2) Voltage and electrical loading conditions on each pin of
rates rather than dose rate. Package effects can be minimized
the device during testing,
by adequately decoupling the power supply with appropriate
(3) Resolution and accuracy required for the upset response
high-speed capacitors.
threshold of individual devices, along with the method used to
6.5 Steps Between Radiation Levels—The size of the steps
vary the radiation level,
between successive radiation levels limits the accuracy with
(4) Failure criterion for transient voltage upset, output
which the dose rate upset threshold is determined. Cost
current, and power supply current as applicable,
considerations and ionizing dose damage limit the number of
(5) Measuring and reporting I , transient output voltage
pp
radiation levels that can be used to test a given device.
and transient output current levels,
(6) Functional test to be made after irradiation, 6.6 Limited Number of State Vectors—Cost, testing time,
(7) Power supply and operating frequency requirements, and cumulative ionizing radiation usually make it necessary to
(8) State vectors used for testing, restrict upset testing to a small number of state vectors. These
(9) Radiation levels to use for transient response measure- state vectors must include the most sensitive conditions in
ments, order to avoid misleading results. An analysis is required to
(10) Recommendedradiationlevelatwhichtobeginthetest select the state vectors used for radiation testing to make sure
sequence, and that circuit and geometrical factors that affect the upset
(11) Procedure to adjust the dose rate during testing. response are taken into account.
F 1262M–95 (2002)
7. Apparatus response to transient ionizing radiation is much smaller than
that of the circuit being measured (see Note 4).
7.1 The equipment and information required for this guide
includes an electrical schematic of the test circuit, a logic
NOTE 4—Although line drivers are normally not placed in the direct
diagram of the device to be tested, a transient radiation
radiation beam, there is always some stray radiation that may affect the
line driver. Furthermore, replacement currents in the wiring that connects
simulation source, dosimetry equipment, and electrical equip-
the line driver to the circuit under test may also introduce a spurious
ment for the measurement of the device response and func-
response.
tional testing. If the alternate topological analysis approach is
to be used, (see 8.2.2) then a photomicrograph or composite
7.3.3 General Purpose Test Equipment—Power supplies,
mask drawing of the device is also needed.
pulse generators, cables and termination resistors that are
7.2 Radiation Simulation and Dosimetry Apparatus: required to bias the device and establish its internal operating
conditions are needed.
7.2.1 Transient Radiation Source—A pulsed high energy
electron or bremsstrahlung source that can provide a dose rate
7.3.4 Transient Response Measuring Device—An oscillo-
in excess of the upset response threshold level of the device scope, transient digitizer or similar device shall be used to
being tested at the pulse width specified in the test plan is
measure the transient response of the device under test. The
needed.Alinear accelerator (LINAC) with electron energies of bandwidth and sensitivity of this equipment must be compat-
10 to 25 MeV is preferred (see Note 1), although in some
ible with the pulse width and measurement criteria in the test
instances a flash X ray with end point energy above 2.0 MeV plan.
may be utilized (see Note 2 and Note 3). It is usually much
7.3.5 Functional Test System—Asystem that is set up to test
more difficult to synchronize a flash X-ray pulse with circuit
the functional operation of the device under test while it is in
operation, which limits the applicability of a flash X ray.
the radiation test fixture is required. This may consist of (1)
general purpose equipment such as pulse generators,
NOTE 1—Linac radiation pulses are made from a train of discrete
oscilloscopes/transient digitizers, or logic analyzers, (2)a
“micropulses” occurring at the linac radio frequency (RF). This high
commercial integrated circuit test system, or (3) a custom test
frequencypulsestructurecouldcauseerroneousresultsforhighfrequency
devices under test such as gallium arsenide. This has not yet been directly circuit/fixture. The specific requirements of the functional test
observed.
system depend on the specifications and requirements of the
NOTE 2—The absorption coefficient of photons in silicon and packag-
device under test and are included in the test plan.
ing materials is relatively flat at energies above 2 MeV, and has a nearly
7.3.6 Temperature Measuring Equipment—A thermometer,
constant ratio to the absorption coefficient of typical dosimetry systems.
calorimeter, or other temperature measuring device that can
At lower energies absorption coefficients increase, which can introduce
measure the ambient temperature with an accuracy of at least
large dosimetry errors if the end point energy in a bremsstrahlung source
63°C.
is below 2.0 MeV.
NOTE 3—Because of dose enhancement and attenuation, a transport
calculation is generally required to relat
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