IEC 60749-18:2019

IEC 60749-18 ®
Edition 2.0 2019-04
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Semiconductor devices – Mechanical and climatic test methods –
Part 18: Ionizing radiation (total dose)

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IEC 60749-18 ®
Edition 2.0 2019-04
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Semiconductor devices – Mechanical and climatic test methods –

Part 18: Ionizing radiation (total dose)

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.080.01 ISBN 978-2-8322-6832-2

– 2 – IEC 60749-18:2019 RLV © IEC 2019
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Test apparatus . 8
4.1 Choice of apparatus . 8
4.2 Radiation source . 8
4.3 Dosimetry system . 8
4.4 Electrical test instruments . 8
4.5 Test circuit board(s) . 8
4.6 Cabling . 9
4.7 Interconnect or switching system . 9
4.8 Environmental chamber . 9
4.9 Irradiation temperature chamber . 9
5 Procedure . 9
5.1 Test plan . 9
5.2 Sample selection and handling . 9
5.3 Burn-in . 10
5.4 Dosimetry measurements . 10
5.5 Lead/aluminium (Pb/Al) container . 10
5.6 Radiation level(s) . 10
5.7 Radiation dose rate . 10
5.7.1 Radiation dose rate determination . 10
5.7.2 Condition A . 10
5.7.3 Condition B . 11
5.7.4 Condition C . 11
5.7.5 Condition D . 11
5.7.6 Condition E . 11
5.8 Temperature requirements . 11
5.8.1 Room temperature radiation . 11
5.8.2 Elevated temperature irradiation . 12
5.8.3 Cryogenic temperature irradiation . 12
5.9 Electrical performance measurements . 12
5.10 Test conditions . 12
5.10.1 Choice of test conditions. 12
5.10.2 In-flux testing . 12
5.10.3 Remote testing . 13
5.10.4 Bias and loading conditions . 13
5.11 Post-irradiation procedure . 13
5.12 Extended room temperature annealing test . 14
5.12.1 Choice of annealing test . 14
5.12.2 Need to perform an extended room temperature annealing test . 14
5.12.3 Extended room temperature annealing test procedure . 14
5.13 MOS accelerated annealing test . 15
5.13.1 Choice of MOS accelerated annealing test . 15
5.13.2 Need to perform accelerated annealing test . 15

5.13.3 Accelerated annealing test procedure . 16
5.14 Test procedure for bipolar and BiCMOS linear or mixed signal devices with
intended application dose rates less than 0,5 Gy(Si)/s . 16
5.14.1 Need to perform ELDRS testing . 16
5.14.2 Determination of whether a part exhibits ELDRS. 17
5.14.3 Characterization of ELDRS parts to determine the irradiation conditions
for production or lot acceptance testing . 17
5.14.4 Low dose rate or elevated temperature irradiation test for bipolar or
BiCMOS linear or mixed-signal devices . 18
5.15 Test report . 18
6 Summary . 18
Bibliography . 22

Figure 1 – Flow diagram for ionizing radiation test procedure for MOS and digital
bipolar devices. 20
Figure 2 – Flow diagram for ionizing radiation test procedure for bipolar (or BiCMOS)
linear or mixed-signal devices . 21

– 4 – IEC 60749-18:2019 RLV © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SEMICONDUCTOR DEVICES –
MECHANICAL AND CLIMATIC TEST METHODS –

Part 18: Ionizing radiation (total dose)

FOREWORD
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International Standard IEC 60749-18 has been prepared by IEC technical committee 47:
Semiconductor devices.
This second edition cancels and replaces the first edition published in 2002. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) updates to subclauses to better align the test method with MIL-STD 883J, method 1019,
including the use of enhanced low dose rate sensitivity (ELDRS) testing;
b) addition of a Bibliography, which includes ASTM standards relevant to this test method.
The text of this International Standard is based on the following documents:
FDIS Report on voting
47/2539/FDIS 47/2554/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 60749 series, published under the general title Semiconductor
devices – Mechanical and climatic test methods, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The “colour inside” logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this publication using a colour printer.

– 6 – IEC 60749-18:2019 RLV © IEC 2019
SEMICONDUCTOR DEVICES –
MECHANICAL AND CLIMATIC TEST METHODS –

Part 18: Ionizing radiation (total dose)

1 Scope
This part of IEC 60749 provides a test procedure for defining requirements for testing
packaged semiconductor integrated circuits and discrete semiconductor devices for ionizing
radiation (total dose) effects from a cobalt-60 ( Co) gamma ray source. Other suitable
radiation sources can be used.
This standard provides an accelerated annealing test for estimating low dose rate ionizing
radiation effects on devices. This annealing test is important for low dose rate or certain other
applications in which devices may exhibit significant time-dependent effects.
There are four tests presented in this procedure:
a) a standard room temperature irradiation test;
b) an irradiation at elevated temperature/cryogenic temperature test;
c) an accelerated annealing test;
d) an enhanced low dose rate sensitivity (ELDRS) test.
The accelerated annealing test estimates how dose rate ionizing radiation effects on devices
is important for low dose rate or certain other applications in which devices can exhibit
significant time-dependent effects. The ELDRS test determines if devices with bipolar linear
components exhibit sensitivity to enhanced radiation-induced damage at low dose rates.
This document addresses only steady-state irradiations, and is not applicable to pulse type
irradiations.
It is intended for military- and aerospace-related applications.
This document may can produce severe degradation of the electrical properties of irradiated
devices and thus should be is considered a destructive test.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp

3.1
ionizing radiation effects, pl
changes in the electrical parameters of a device or integrated circuit resulting from radiation-
induced charge
Note 1 to entry: These are also referred to as total dose effects.
3.2
in-flux test
electrical measurements made on devices during irradiation exposure
3.3
internal dose pattern
logic condition of all elements within a logic circuit during radiation exposure
3.4
non in-flux test
electrical measurements made on devices at any time other than during irradiation
3.5
remote test
electrical measurements made on devices that are physically removed from the radiation
location
3.6
time-dependent effect
TDE
significant degradation in electrical parameters caused by the growth or annealing, or both, of
radiation-induced trapped charge after irradiation
Note 1 to entry: Similar effects also take place during irradiation.
Note 2 to entry: This note applies to the French language only.
3.7
accelerated annealing test
procedure utilizing elevated temperature to accelerate time-dependent effects
3.8
enhanced low dose rate sensitivity
ELDRS
part that shows enhanced radiation-induced damage at dose rates below 0,5 Gy(Si)/s
Note 1 to entry: This note applies to the French language only.
3.9
overtest
factor that is applied to the specification dose to determine the test dose level that the
samples have to pass to be acceptable at the specification level
Note 1 to entry: An overtest factor of 1,5 means that the parts should be tested at 1,5 times the specification dose.
3.10
parameter delta design margin
PDDM
design margin that is applied to the radiation-induced change in an electrical parameter
Note 1 to entry: For a PDDM of 2 the change in a parameter at a specified dose from the pre-irradiation value is
multiplied by two and added to the pre-irradiation value to see if the sample exceeds the post-irradiation parameter
limit. For example, if the pre-irradiation value of base current I is 30 nA and the post-irradiation value at 200 Gy(Si)
b
– 8 – IEC 60749-18:2019 RLV © IEC 2019
is 70 nA (change in I is 40 nA), then for a PDDM of 2 the post-irradiation value would be 110 nA
b
(30 nA + 2 x 40 nA). If the allowable post-irradiation limit is 100 nA, the part would fail.
4 Test apparatus
4.1 Choice of apparatus
The apparatus shall consist of the radiation source, electrical test instrumentation, test circuit
board(s), cabling, interconnect board or switching system, an appropriate dosimetry
measurement system, and an environmental chamber (if required for time-dependent effects
measurements). Adequate precautions shall be observed to obtain an electrical measurement
system with sufficient insulation, ample shielding, satisfactory grounding, and suitable low
noise characteristics.
4.2 Radiation source
The radiation source used in the test shall be the uniform field of a Co gamma ray source.
Uniformity of the radiation field in the volume where devices are irradiated shall be within ±10 %
as measured by the dosimetry system, unless otherwise specified. The intensity of the gamma
Co source shall be known with an uncertainty of no more than ±5 %. Field
ray field of the
uniformity and intensity can be affected by changes in the location of the device with respect
to the radiation source and the presence of radiation absorption and scattering materials.
4.3 Dosimetry system
An appropriate dosimetry system shall be provided that is capable of carrying out the
measurements called for in 5.3 (see Bibliography).
4.4 Electrical test instruments
All instrumentation used for electrical measurements shall have the stability, accuracy, and
resolution required for accurate measurement of the electrical parameters. Any
instrumentation required to operate in a radiation environment shall be appropriately shielded.
4.5 Test circuit board(s)
Devices to be irradiated shall either be mounted on or connected to circuit boards together
with any associated circuitry necessary for device biasing during irradiation or for in situ
measurements. Unless otherwise specified, all device input terminals and any others
which may can affect the radiation response shall be electrically connected during irradiation,
i.e. not left floating.
The geometry and materials of the completed board shall allow uniform irradiation of the
devices under test. Good design and construction practices shall be used to prevent
oscillations, minimize leakage currents, prevent electrical damage and obtain accurate
measurements. Only sockets that are radiation resistant and do not exhibit significant
leakages (relative to the devices under test) shall be used to mount devices and associated
circuitry to the test board(s).
All apparatus used repeatedly in radiation fields shall be checked periodically for physical or
electrical degradation. Components which are placed on the test circuit board, other than
devices under test, shall be insensitive to the accumulated radiation or they shall be shielded
from the radiation. Test fixtures shall be made such that materials will not perturb the
uniformity of the radiation field intensity on the devices under test.
Leakage current shall be measured outside the field of radiation. With no devices installed in
the sockets, the test circuit board shall be connected to the test system such that all expected
sources of noise and interference are operative. With the maximum specified bias for the test
device applied, the leakage current between any two terminals shall not exceed 10 % of the
lowest current limit value in the pre-irradiation device specification.

Test circuit boards used to bias devices during accelerated annealing must shall be capable
of withstanding the temperature requirements of the accelerated annealing test and shall be
checked before and after testing for physical and electrical degradation.
4.6 Cabling
Cables connecting the test circuit boards in the radiation field to the test instrumentation shall
be as short as possible. If long cables are necessary, line drivers may can be required. The
cables shall have low capacitance and low leakage to ground, and low leakage between wires.
4.7 Interconnect or switching system
This system shall be located external to outside the radiation environment location, and
provides the interface between the test instrumentation and the devices under test. It is part
of the entire test system and subject to the limitation specified in 4.5 for leakage between
terminals.
4.8 Environmental chamber
The environmental chamber for time-dependent effects testing, if required, shall be capable of
maintaining the selected accelerated annealing temperature within ±5 °C.
4.9 Irradiation temperature chamber
The irradiation temperature chamber, if required for elevated temperature irradiation should
be capable of maintaining a circuit under test at 100 °C ± 5 °C while it is being irradiated. The
chamber should be capable of raising the temperature of the circuit under test from room
temperature to the irradiation temperature within a reasonable time prior to irradiation and
cooling the circuit under test from the irradiation temperature to room temperature in less than
20 min following irradiation. The irradiation bias shall be maintained during the heating and
cooling. The method for raising, maintaining and lowering the temperature of the circuit under
test can be by conduction through a heat sink using heating and cooling fluids, by convection
using forced hot and cool air, or other means that will achieve the proper results. For
cryogenic temperature irradiations, the chamber should be capable of maintaining the test
device/unit at the required cryogenic temperature within ±5 °C (e.g., liquid helium or liquid
nitrogen) while it is being irradiated. The chamber should be capable of maintaining the
cryogenic temperature of the test device/unit during post-irradiation electrical testing.
5 Procedure
5.1 Test plan
The test devices shall be irradiated and subjected to accelerated annealing testing (if required
for time-dependent effects testing) as specified by a test plan. This plan shall specify the
device description, irradiation conditions, device bias conditions, dosimetry system, operating
conditions, measurement parameters and conditions and accelerated annealing test
conditions (if required).
5.2 Sample selection and handling
Only devices that have passed the electrical specifications as defined in the test plan shall be
submitted to radiation testing. Unless otherwise specified, the test samples shall be randomly
selected from the parent population and identically packaged. Each part shall be individually
identifiable to enable pre- and post-irradiation comparison. For device types that are
electrostatic discharge (ESD)-sensitive, proper handling techniques shall be used to prevent
damage to the devices.
– 10 – IEC 60749-18:2019 RLV © IEC 2019
5.3 Burn-in
For some devices, there are differences in the total dose radiation response before and after
burn-in. Unless it has been shown by prior characterization or by design that burn-in has a
negligible effect (parameters remain within post-irradiation specified electrical limits) on the
total dose radiation response, then one of the following functions must shall take place:
a) the manufacturer shall subject the radiation samples to the specified burn-in conditions
prior to conducting total dose radiation testing; or
b) the manufacturer shall develop a correction factor, (which is acceptable to the parties to
the test) taking into account the changes in total dose response resulting from subjecting
the product to burn-in. The correction factor shall then be used to accept the product for
total dose response without subjecting the test samples to burn-in.
5.4 Dosimetry measurements
The radiation field intensity at the location of the device under test shall be determined prior
to testing by dosimetry or by source decay correction calculations, as appropriate, to ensure
conformance to the test level and uniformity requirements.
The dose applied to the device under test shall be determined in one of two ways:
a) by measurement during the irradiation with an appropriate dosimeter; or
Co source intensity in
b) by correcting a previous dosimetry value for the decay of the
the intervening time. Appropriate correction shall be made to convert from the measured
or calculated dose in the dosimeter material to the dose in the device under test.
5.5 Lead/aluminium (Pb/Al) container
Test specimens shall be enclosed in a Pb/Al container to minimize dose enhancement effects
caused by low-energy scattered radiation. A minimum of 1,5 mm of lead (Pb), surrounding an
inner shield of at least 0,7 mm aluminium (Al) is required. This Pb/Al container produces an
approximate charged particle equilibrium for Si and for thermoluminescence dosimetries
(TLDs) such as CaF2. The radiation field intensity shall be measured inside the Pb/Al
container (1) initially, (2) when the source is changed, or (3) when the orientation or
configuration of the source, container or test-fixture is changed. This measurement shall be
performed by placing a dosimeter (e.g. a TLD) in the device-irradiation container at the
approximate test-device position. If it can be demonstrated that low energy scattered radiation
is small enough that it will not cause dosimetry errors due to dose enhancement, the Pb/Al
container may be omitted.
5.6 Radiation level(s)
The test devices shall be irradiated to the dose level(s) specified in the test plan within ±10 %.
If multiple irradiations are required for a set of test devices, then the post-irradiation electrical
parameter measurements shall be performed after each irradiation.
5.7 Radiation dose rate
5.7.1 Radiation dose rate determination
CAUTION: For the application of some bipolar and biCMOS devices to space-level dose rates,
testing at condition A dose rates may not provide worst case results. These are devices that
fail due to reduced transistor gain.
NOTE For those bipolar and biCMOS devices, where the application involves space-level dose rates and the
excess base current has been observed to increase at decreasing dose rates, testing may be accomplished at
the lowest dose rate of interest in accordance with Condition C in order to obtain a conservative estimate of the
device performance.
The radiation dose rate for bipolar and BiCMOS linear or mixed-signal parts used in
applications where the maximum dose rate is below 0,5 Gy(Si)/s shall be determined as
described in 5.14. Parts used in low dose rate applications, unless they have been
demonstrated to not exhibit an ELDRS response shall use condition C, condition D, or
condition E.
A flow diagram for ionizing test procedures for MOS and digital bipolar devices is shown in
Figure 1. A flow diagram for ionizing radiation test procedure for bipolar
(or BiCMOS) linear or mixed-signal devices is shown in Figure 2.
NOTE Devices that contain both MOS and bipolar devices can require qualification to multiple subconditions to
ensure that both ELDRS and traditional MOS effects are evaluated.
5.7.2 Condition A
For condition A (standard condition), the dose rate shall be between 0,5 Gy(Si)/s and
3 Gy(Si)/s for integrated circuits and between 0,5 Gy(Si)/s and 20 Gy(Si)/s for discrete
semi-conductor devices. The dose rates may be different for each radiation dose level in
a series; however, the dose rate shall not vary by more than ±10 % during each irradiation.
5.7.3 Condition B
For condition B, for MOS devices only, if the maximum dose rate is < less than 0,5 Gy(Si)/s in
the intended application, the parties to the test may can agree to perform the test at a dose
rate greater than or equal to the maximum dose rate of the intended application. Unless the
exclusions in 5.13.2 b) are met, the accelerated annealing test of 5.13.3 shall be performed.
5.7.4 Condition C
For condition C, (as an alternative) the test may be performed at the dose rate of the intended
application if this is agreed to by the parties to the test. Where the final user is not known, the
test conditions and results shall be made available in the test report with each purchase order.
5.7.5 Condition D
For condition D, for bipolar or BiCMOS linear or mixed-signal devices only, the parts shall be
irradiated at less than or equal to 0,1 mGy(Si)/s.
5.7.6 Condition E
For condition E, for bipolar or BiCMOS linear or mixed-signal devices only, the parts shall be
irradiated with the accelerated test conditions determined by characterization testing as
discussed in 5.14.3. The accelerated test may include irradiation at an elevated temperature.
5.8 Temperature requirements
5.8.1 Room temperature radiation
Since radiation effects are temperature dependent, devices under test shall be irradiated in an
ambient temperature of 24 °C ± 6 °C as measured at a point in the test chamber in close
proximity to the test fixture. The electrical measurements shall be performed in an ambient
temperature of 25 24 °C ± 5 6 °C. If devices are transported to and from a remote electrical
measurement site, the temperature of the test devices shall not be allowed to increase by
more than 10 °C from the irradiation environment. If any other temperature range is required,
it shall be specified.
Caution: Annealing at ambient temperatures above the irradiation temperature can be
significant, especially for the extended times allowed for the time between irradiations at low
dose rate (condition D). It is important to ensure that the temperature of the parts is
maintained within the above stated requirements to minimize annealing.

– 12 – IEC 60749-18:2019 RLV © IEC 2019
5.8.2 Elevated temperature irradiation
For bipolar or BiCMOS linear or mixed-signal devices irradiated using the condition E
elevated temperature irradiation test, devices under test shall be irradiated in an ambient
temperature determined by characterization testing (see 5.14.3) as measured at a point in the
test chamber in close proximity to the test fixture (see 4.8 for details on raising and lowering
the irradiation temperature).
5.8.3 Cryogenic temperature irradiation
For test devices/units operated in cryogenic temperature applications, the devices/units shall
be irradiated at cryogenic temperature (see 4.8) and maintained at cryogenic temperature for
post exposure characterization testing (see 5.11). The test device/units shall remain at
cryogenic temperature throughout all irradiations and characterization testing until the final
total dose exposure and characterization have been completed.
5.9 Electrical performance measurements
The electrical parameters to be measured and functional tests to be performed shall be
specified in the test plan. As a check on the validity of the measurement system and pre- and
post-irradiation data, at least one control sample shall be measured using the operating
conditions provided in the governing device specifications. For automatic test equipment,
there is no restriction on the test sequence provided that the rise in the device junction
temperature is minimized. For manual measurements, the sequence of parameter
measurements shall be chosen to allow the shortest possible measurement period. When a
series of measurements is made, the tests shall be arranged so that the lowest power
dissipation in the device occurs in the earliest measurements and the power dissipation
increases with subsequent measurements in the sequence.
The pre- and post-irradiation electrical measurements shall be carried out on the same
measurement system and the same sequence of measurements shall be maintained for each
series of electrical measurements of devices in a test sample. Pulse-type measurements of
electrical parameters should be used as appropriate to minimize heating and subsequent
annealing effects. Devices which will be subjected to the accelerated annealing testing (see
5.13) may be given a pre-irradiation burn-in to eliminate burn-in related failures.
5.10 Test conditions
5.10.1 Choice of test conditions
The use of in-flux or non in-flux testing shall be specified in the test plan. (This may can
depend on the intended application for which the data are being obtained.) The use of in-flux
testing may can help to avoid variations introduced by post-irradiation time-dependent effects.
However, errors may can occur for the situation where a device is irradiated in-flux with static
bias, but where the electrical testing conditions require the use of dynamic bias for a
significant fraction of the total irradiation period. Non-in-flux testing generally allows for more
comprehensive electrical testing, but can be misleading if significant post-irradiation time-
dependent effects occur.
5.10.2 In-flux testing
Each test device shall be checked for operation within specifications prior to being irradiated.
After the entire system is in place for the in-flux radiation test, it shall be checked for proper
interconnections, leakage (see 4.5), and noise level. To ensure the proper operation and
stability of the test set-up, a control device with known parameter values shall be measured at
all operational conditions called for in the test plan. This measurement shall be carried out
either before the insertion of test devices or upon completion of the irradiation after removal
of the test devices or both.
5.10.3 Remote testing
Unless otherwise specified, the bias shall be removed and the device leads placed in
conductive foam (or similarly shorted) during transfer from the irradiation source to a remote
tester and back again for further irradiation. This minimizes post-irradiation time-dependent
effects.
5.10.4 Bias and loading conditions
Bias conditions for test devices during irradiation or accelerated annealing shall be within
±10 % of those specified by the test plan. The bias applied to the test devices shall be
selected to produce the greatest radiation-induced damage or the worst-case damage for the
intended application, if known. The bias, loading and internal dose-pattern conditions shall
remain constant throughout a step-wise total ionizing dose exposure and anneal. If any of the
bias, loading or internal dose-pattern conditions are not at the worst-case condition, then a
justification for the conditions used shall be provided in the test plan and test report. While
maximum voltage is often worst case some bipolar linear device parameters (e.g. input bias
current or maximum output load current) exhibit more degradation with 0 V bias. The specified
bias shall be maintained on each device in accordance with the test plan. Bias shall be
checked immediately before and after irradiation. Care shall be taken in selecting the loading
such that the rise in the junction temperature is minimized.
5.11 Post-irradiation procedure
Unless otherwise specified, the following time intervals shall be observed:
a) The time from the end of an irradiation to the start of electrical measurements shall be a
maximum of 1 h for condition A. For conditions B, C, D and E, the time from the end of an
irradiation to the start of electrical measurements may be equal to 10 % of the incremental
irradiation time up to (but not exceeding) 72 h if this time is greater than 1 h, otherwise it
shall be a maximum of 1 h. As an option for remote electrical testing, for conditions A, B,
C, D and E, parts may be packed in dry ice until the start of electrical testing, but only if
packed within 15 min after the completion of irradiation. While in dry ice, the part leads
shall be shorted, the parts shall be verifiably maintained at a maximum temperature of
−60 °C, and the time from completion of irradiation until the start of electrical testing may
not exceed 72 h. The electrical testing shall be conducted after the parts have been
restored to room temperature but within 30 min after the parts are removed from the dry
ice. Electrical testing shall be as specified in 5.8.1. The times at room temperature and
the times and temperature for the dry ice procedure may be different if demonstrated by a
characterization test as described in 5.11 c) below.
b) The time to perform the electrical measurements and to return the device for a
subsequent irradiation, if any, shall be within 2 h of the end of the prior irradiation for
condition A. For conditions B, C, D and E, the time to perform the electrical measurements
and to return the device for a subsequent irradiation, if any, may be equal to 20 % of the
incremental irradiation time up to (but not exceeding) 120 h if this time is greater than 2 h,
otherwise it shall be a maximum of 2 h. As an option for continued additional irradiation
when parts are electrically tested at a remote location, for conditions A, B, C, D and E
parts may be packed in dry ice until the start of irradiation, but only if packed within
15 min after the completion of electrical testing. While in the dry ice, the part leads shall
be shorted, the parts shall be verifiably maintained at a maximum temperature of −60 °C,
and the time from completion of electrical testing until the start of irradiation may not
exceed 72 h. The radiation exposure shall begin after the parts have been restored to
room temperature but within 30 min after the parts are removed from the dry ice. The
times at room temperature and the times and temperature for the dry ice procedure may
be different if demonstrated by a characterization test as described in 5.11 c) below.
c) If the dry ice test method is used, the characterization test shall be performed on
annealing at the particular technology node of study to demonstrate that the annealing will
be less than 10 % for all critical parameters compared to room temperature data taken
within 1 h after irradiation. Other times and temperatures than those listed in 5.11 a) and
5.11 b) may be considered as part of the characterization test. However, the time for
electrical measurements following irradiation shall not exceed 72 h and the time between

– 14 – IEC 60749-18:2019 RLV © IEC 2019
successive irradiations shall not exceed 120 h. For example, if the manufacturer’s cold
temperature specification limit is higher than −60 °C this higher temperature may be
allowed. For another example, if the parts show very little annealing at room temperature
following condition A irradiation, the 1-h and 2-h limits could be increased. For any
exceptions to the times and temperatures in 5.11 a) and 5.11 b) it shall be demonstrated
that the annealing under these different conditions is within 10 % for all critical parameters
compared to room temperature data taken within 1 h after irradiation, or the appropriate
time limit for the irradiation test condition, if greater than 1 h. The characterization test
results shall be included with the test report as specified in 5.15.
To minimize time-dependent effects, these intervals shall be as short as possible. The
sequence of parameter measurements shall be maintained constant throughout the
tests series.
5.12 Extended room temperature annealing test
5.12.1 Choice of annealing test
The tests of 5.2 to 5.11 are known to be overly conservative for some devices in a very low
dose rate environment (e.g. dose rates characteristic of space missions). The extended room
temperature annealing test provides an estimate of the performance of a device in a very low
dose rate environment even though the testing is performed at a relatively high dose rate
(e.g. 0,5 Gy
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