ASTM F1892-98
(Guide)Standard Guide for Ionizing Radiation (Total Dose) Effects Testing of Semiconductor Devices
Standard Guide for Ionizing Radiation (Total Dose) Effects Testing of Semiconductor Devices
SCOPE
1.1 This guide presents background and guidelines for establishing an appropriate sequence of tests and data analysis procedures for determining the ionizing radiation (total dose) harness of microelectronic devices for dose rates below 300 rd(SiO2)/s. These tests and analysis will be appropriate to assist in the determination of the ability of the devices under test to meet specific hardness requirements or to evaluate the parts for use in a range of radiation environments.
1.2 The methods and guidelines presented will be applicable to characterization, qualification, and lot acceptance of silicon-based MOS and bipolar discrete devices and integrated circuits. They will be appropriate for treatment of the effects of electron and photon irradiation.
1.3 This guide provides a framework for choosing a test sequence based on general characteristics of the parts to be tested and the radiation hardness requirements or goals for these parts.
1.4 This guide provides for tradeoffs between minimizing the conservative nature of the testing method and minimizing the required testing effort.
1.5 Determination of an effective and economical hardness test typically will require several kinds of decisions. A partial enumeration of the decisions that typically must be made is as follows:
1.5.1 Determination of the Need to Perform Device Characterization-For some cases it may be more appropriate to adopt some kind of worst case testing scheme that does not require device characterization. For other cases it may be most effective to determine the effect of dose-rate on the radiation sensitivity of a device. As necessary, the appropriate level of detail of such a characterization also must be determined.
1.5.2 Determination of an Effective Strategy for Minimizing the Effects of Irradiation Dose Rate on the Test Result-The results of radiation testing on some types of devices are relatively insensitive to the dose rate of the radiation applied in the test. In constrast, many MOS devices and some bipolar devices have a significant sensitivity to dose rate. Several different strategies for managing the dose rate sensitivity of test results will be discussed.
1.5.3 Choice of an Effective Test Methodology-The selection of effective test methodologies will be discussed.
1.6 Low Dose Requirements-Hardness testing of MOS and bipolar microelectronic devices for the purpose of qualification or lot acceptance is not neceassary when the required hardness is 100 rd(SiO2) or lower.
1.7 Sources-This guide will cover effects due to device testing using irradiation from photon sources, such as 60Co y irradiators, 137Cs y irradiators, and low energy (approximately 10 keV) X-ray sources. Other sources of test radiation such as linacs, Van de Graaff sources, Dymnamitrons, SEM's and flash X-ray sources occasionally are used but are outside the scope of this guide.
1.8 Displacement damage effects are outside the scope of this guide, as well.
1.9 The values stated in SI units are to be regarded as the standard.
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Designation: F 1892 – 98
Standard Guide for
Ionizing Radiation (Total Dose) Effects Testing of
Semiconductor Devices
This standard is issued under the fixed designation F 1892; 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.
INTRODUCTION
This guide is designed to assist investigators in performing ionizing radiation effects testing of
semiconductor devices, commonly termed total dose testing. When actual use conditions, which
includes dose, dose rate, temperature, and bias conditions and the time sequence of application of
these conditions, are the same as those used in the test procedure, the results obtained using these test
methods apply without qualification. For some part types, results obtained when following this guide
are much more broadly applicable. There are many part types, however, where care must be used in
extrapolating test results to situations that do not duplicate all aspects of the test conditions in which
the response data were obtained. For example, some linear bipolar devices and devices containing
metal oxide semiconductor (MOS) structures require special treatment. This guide provides direction
for appropriate testing of such devices.
1. Scope 1.5.1 Determination of the Need to Perform Device
Characterization—For some cases it may be more appropriate
1.1 This guide presents background and guidelines for
to adopt some kind of worst case testing scheme that does not
establishing an appropriate sequence of tests and data analysis
require device characterization. For other cases it may be most
procedures for determining the ionizing radiation (total dose)
effective to determine the effect of dose-rate on the radiation
hardness of microelectronic devices for dose rates below 300
sensitivity of a device. As necessary, the appropriate level of
rd(SiO )/s. These tests and analysis will be appropriate to assist
detail of such a characterization also must be determined.
in the determination of the ability of the devices under test to
1.5.2 Determination of an Effective Strategy for Minimizing
meet specific hardness requirements or to evaluate the parts for
the Effects of Irradiation Dose Rate on the Test Result—The
use in a range of radiation environments.
results of radiation testing on some types of devices are
1.2 The methods and guidelines presented will be applicable
relatively insensitive to the dose rate of the radiation applied in
to characterization, qualification, and lot acceptance of silicon-
the test. In contrast, many MOS devices and some bipolar
based MOS and bipolar discrete devices and integrated cir-
devices have a significant sensitivity to dose rate. Several
cuits. They will be appropriate for treatment of the effects of
different strategies for managing the dose rate sensitivity of test
electron and photon irradiation.
results will be discussed.
1.3 This guide provides a framework for choosing a test
1.5.3 Choice of an Effective Test Methodology—The selec-
sequence based on general characteristics of the parts to be
tion of effective test methodologies will be discussed.
tested and the radiation hardness requirements or goals for
1.6 Low Dose Requirements—Hardness testing of MOS and
these parts.
bipolar microelectronic devices for the purpose of qualification
1.4 This guide provides for tradeoffs between minimizing
or lot acceptance is not necessary when the required hardness
the conservative nature of the testing method and minimizing
is 100 rd(SiO ) or lower.
the required testing effort.
1.7 Sources—This guide will cover effects due to device
1.5 Determination of an effective and economical hardness
testing using irradiation from photon sources, such as Co g
test typically will require several kinds of decisions. A partial
irradiators, Cs g irradiators, and low energy (approximately
enumeration of the decisions that typically must be made is as
10 keV) X-ray sources. Other sources of test radiation such as
follows:
linacs, Van de Graaff sources, Dymnamitrons, SEM’s, and
flash X-ray sources occasionally are used but are outside the
This guide is under the jurisdiction of ASTM Committee F-01 on Electronics
scope of this guide.
and is the direct responsibility of Subcommittee F01.11 on Quality Hardness
1.8 Displacement damage effects are outside the scope of
Assurance.
this guide, as well.
Current edition approved May 10, 1998. Published November 1998.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F 1892
1.9 The values stated in SI units are to be regarded as the 3.2.9 ionizing radiation effects, n—the changes in the elec-
standard. trical parameters of a microelectronic device resulting from
radiation-induced trapped charge.
2. Referenced Documents
3.2.9.1 Discussion—Ionizing radiation effects are some-
times referred to as“ total dose effects.”
2.1 ASTM Standards:
3.2.10 low dose rate sensitive, adj—used to refer to a
E 170 Terminology Relating to Radiation Measurements
bipolar part that shows enhanced radiation induced damage at
and Dosimetry
dose rates below about 50 rd(SiO )/s.
E 666 Practice for Calculating Absorbed Dose from Gamma
3.2.10.1 Discussion—In this guide, doses and dose rates are
or X Radiation
specified in rd(SiO ) as contrasted with the use of rd(Si) in
E 668 Practice for the Application of Thermoluminescence-
other related standards. The reason is that for ionizing radiation
Dosimetry (TLD) Systems for Determining Absorbed Dose
effects in silicon based microelectronic components, it is the
in Radiation-Hardness Testing of Electronic Devices
energy deposited in the SiO gate, field, and spacer oxides that
E 1249 Practice for Minimizing Dosimetry Errors in Radia- 2
is responsible for the radiation-induced degradation effects. For
tion Hardness Testing of Silicon Electronic Devices Using
high energy irradiation, for example, Co photons, the differ-
Co-60 Sources
ence between dose deposited in Si and SiO typically is
E 1250 Test Method for Application of Ionization Cham-
negligible. For X-ray irradiation, approximately 10 keV photon
bers to Assess the Low Energy Gamma Component of
energy, the energy deposited in Si under some circumstances
Cobalt-60 Irradiators Used in Radiation-Hardness Testing
may be approximately 1.8 times the energy deposited in SiO .
of Silicon Electronic Devices
For additional details, see Guide F 1467.
E 1275 Practice for Use of a Radiochromic Film Dosimetry
3.2.11 not in-flux test, n—electrical measurements made on
System
devices at any time other than during irradiation.
F 1467 Guide for Use of an X-Ray Tester (’ 10 keV
3.2.12 qualification, n—testing to determine the adequacy
Photons) in Ionizing Radiation Effects Testing of Semicon-
of a part to meet the requirements of a specific application.
ductor Devices and Microcircuits
3.2.13 rad, n—the rad symbol, rd, is a commonly used unit
2.2 Military Specifications:
for absorbed dose, defined in terms of the SI unit of absorbed
MIL-STD-883, Method 1019, Ionizing Radiation (Total
dose as 1 rd 5 0.01 Gy.
Dose) Test Method
3.2.14 remote tests, n—electrical measurements made on
MIL-HDBK-814 Ionizing Dose and Neutron Hardness As-
devices that are removed physically from the irradiation
surance Guidelines for Microcircuits and Semiconductor
location for the measurements.
Devices
3.2.15 time dependent effects (TDE), n—the time dependent
3. Terminology growth and annealing of ionizing radiation induced trapped
charge and interface states and the resulting transistor or IC
3.1 For terms relating to radiation measurements and do-
parameter changes caused by these effects.
simetry, see Terminology E 170.
3.2.15.1 Discussion—Similar effects also take place during
3.2 Definitions of Terms Specific to This Standard:
irradiation. Because of the complexity of time dependent
3.2.1 accelerated annealing test, n—procedure utilizing
effects, alternative, but not inconsistent, definitions may prove
elevated temperature to accelerate time-dependent growth and
useful. Two of these are: the complex of time-dependent
annealing of trapped charge.
processes that alter trapped oxide change (DN ) and interface
3.2.2 category A, n—used to refer to a bipolar part that is ot
trap density (DN ) in an MOS or bipolar structure during and
it
not low dose rate sensitive.
after irradiation; and, the effects of these processes upon device
3.2.3 category B, n—used to refer to a bipolar part that is
or circuit characteristics or performance, or both.
low dose rate sensitive.
3.2.4 characterization, n—testing to determine the effect of
4. Summary of Guide
dose, dose-rate, bias, temperature, etc. on the radiation induced
4.1 This guide is designed to provide an introduction and
degradation of a part.
direction to the purposes, methods, and strategies of total
3.2.5 gray, adj—the gray (Gy) symbol, is the SI unit of
ionizing dose testing.
absorbed dose, defined as 1 Gy 5 1 J/kg (1 Gy 5 100 rd).
4.1.1 Purposes—Device or system hardness may be mea-
3.2.6 in-flux tests, n—measurements made in-situ while the
sured for several different purposes. These may include device
test device is in the radiation field.
characterization, device qualification, lot acceptance, line
3.2.7 in-situ tests, n—electrical measurements made on
qualification, and studies of device physics.
devices during, or before-and-after, irradiation while they
4.1.2 Methods:
remain in the irradiation location.
4.1.2.1 An ionizing radiation effects test consists of per-
3.2.8 in-source tests, n—an in-flux test.
forming a set of electrical measurements on a device, exposing
the device to ionizing radiation while appropriately biased, and
then performing a set of electrical measurements either during
Annual Book of ASTM Standards, Vol 12.02.
or after irradiation.
Annual Book of ASTM Standards, Vol 10.04.
4.1.2.2 Because several factors enter into the effects of the
Available from the Standardization Documents Order Desk, Building 4, Section
D, 700 Robbins Ave., Philadelphia, PA 19111–5094. radiation on the device, parties to the test must establish and
F 1892
agree to a variety of conditions before the validity of the test will place an upper or lower bound on the excursions that may
can be established or before the results of any one test can be be anticipated for a given device parameter.
compared with those of another. Conditions that must be 4.2 The choice of optimal procedures for the performance of
established and agreed to include the following: total ionizing dose testing typically involves resolution of the
(a) Radiation Source—The type of radiation source ( Co, conflicts between the following four competing requirements:
X-ray, etc.) that is to be used. 4.2.1 Test Fidelity—It is necessary that a test reproduce the
results to be expected in the projected application environment
NOTE 1—The ionizing dose response of many device types has been
to an acceptable degree of precision. The test methodology
shown to depend on the type of ionizing radiation to which the device is
chosen has a strong effect on the precision of the result.
subjected. The selection of a suitable radiation source for use in such a test
must be based on the understanding that the gamma or electron radiation Typically, however, greater test fidelity must be balanced
source will induce a device response that then should be correlated to the
against greater cost. In addition, many environments cannot be
response anticipated in the device application.
reproduced in the laboratory. Often it may be necessary to have
an adequate command of device physics in order to devise
(b) Dose Rate Range—The range of dose rates within which
laboratory tests that adequately match or bound the perfor-
the radiation exposures must take place (see 6.4).
mance to be expected in actual use.
NOTE 2—The response of many devices has been shown to be highly
4.2.2 Reproducibility—It is important to have test proce-
dependent on the rate at which the dose is accumulated. There must be a
dures that can be depended upon to give approximately the
demonstrated correlation between the response of the device under the
same result each time when used by different laboratories.
selected test conditions and the rate at which the device would be expected
Failure to achieve this goal may have significant contract
to accumulate dose in its intended application.
implications. Obtaining this goal typically requires careful
(c) Operating Conditions—The test circuit, electrical biases
attention to the control of experimental variables and to the
to be applied, and the electrical operating sequence, if appli-
development of accurate dosimetry methods.
cable, for the part during irradiation (see 6.3). This includes the
4.2.3 Single-Valued Result—For some purposes, it is desir-
use of in-flux or not in-flux testing.
able to have a test that can be used to simply categorize parts
(d) Electrical Parameters—The measurements that are to be
and that gives one answer for each part. For example, labeling
made on the test devices before, during (if appropriate), and
of parts for the military parts system is facilitated if such a
after (if appropriate) irradiation.
characterization is available. On the other hand, the search for
(e) Time Sequence—The exposure time, the elapsed time
a simple characterization scheme must not be allowed to
between exposure and post-exposure measurements, and the
obscure real dependencies on dose rate, temperature, bias, etc.,
time between irradiations (see 6.5).
which may have a significant effect on operational hardness.
(f) Irradiation Levels—The dose(s) to which the test device
Care must be taken to extrapolate appropriately from the
is to be exposed between measurements (see Practice E 666).
conditions that lead to the test rating to those conditions to be
(g) Dosimetry—The dosimetry technique (TLDs, calorim-
expected in use.
eters, diodes, etc.) to be used. This depends to some extent on
4.2.4 Testability—It is, of course, desirable to obtain a test
the radiation source selection.
that is economical in its use of time, equipment, and personnel.
(h) Temperature—Exposure, measurement, and storage tem-
The perfect test typically will be too expensive to perform. The
perature ranges (see 6.5 and 6.6).
goal is to determine an optimal balance between expense and
(i) Experimental Configuration—The physical arrangement
reliability of results.
of the radiation source, test unit, radiation shielding, and any
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