ASTM F1893-98
(Guide)Guide for Measurement of Ionizing Dose-Rate Burnout of Semiconductor Devices
Guide for Measurement of Ionizing Dose-Rate Burnout of Semiconductor Devices
SCOPE
1.1 This guide defines the detailed requirements for testing microcircuits for short pulse high dose-rate ionization-induced failure. Large flash x-ray (FXR) machines operated in the photon mode, or FXR e-beam facilities are required because of the high dose-rate levels that are necessary to cause burnout. Two modes of test are possible (1) survival test, and (2) A failure level test.
1.2 The values stated in International System of Units (SI) are to be regarded as standard. No other units of measurement are included in this standard.
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Designation: F 1893 – 98
Guide for
Measurement of Ionizing Dose-Rate Burnout of
Semiconductor Devices
This standard is issued under the fixed designation F 1893; 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 (2) parametric failure—a device failure where the device
under test, DUT fails parametric measurements after exposure.
1.1 This guide defines the detailed requirements for testing
3.1.3.1 Discussion—Functional or parameteric failures may
microcircuits for short pulse high dose-rate ionization-induced
be caused by total ionizing dose mechanisms. See interferences
failure. Large flash x-ray (FXR) machines operated in the
for additional discussion.
photon mode, or FXR e-beam facilities are required because of
3.1.4 survival test—A “pass/fail” test performed to deter-
the high dose-rate levels that are necessary to cause burnout.
mine the status of the device after being exposed to a
Two modes of test are possible: (1) A survival test, and (2)A
predetermined dose-rate level. The survival test is usually
failure level test.
considered a destructive test.
1.2 The values stated in International System of Units (SI)
3.1.5 burnout level test—a test performed to determine the
are to be regarded as standard. No other units of measurement
actual dose-rate level where the device experiences burnout.
are included in this standard.
3.1.5.1 Discussion—In such a test, semiconductor devices
2. Referenced Documents
are exposed to a series of irradiations of differing dose-rate
levels. The maximum dose rate at which the device survives is
2.1 ASTM Standards:
determined for worst-case bias conditions. The failure level
E 666 Practice for Calculating Absorbed Dose from Gamma
test is always a destructive test.
or X-Radiation
E 668 Practice for the Application of Thermoluminescence-
4. Summary of Guide
Dosimetry (TLD) Systems for Determining Absorbed Dose
4.1 Semiconductor devices are tested for burnout after
in Radiation-Hardness Testing of Electronic Devices
exposure to high ionizing dose-rate radiation. The measure-
3. Terminology ment for high-dose-rate burnout may be a survival test con-
sisting of a pass/fail measurement at a predetermined level; or
3.1 Definitions:
it may be a failure level test where the actual dose-rate level for
3.1.1 dose rate—energy absorbed per unit time per unit
burnout is determined experimentally.
mass by a given material that is exposed to the radiation field
4.2 The following quantities are unspecified in this guide
(Gy/s, rd/s).
and must be agreed upon between the parties to the test:
3.1.2 high dose-rate burnout—permanent damage to a
4.2.1 The maximum ionizing (total dose to which the
semiconductor device caused by abnormally large currents
devices will be exposed, and
flowing in junctions and resulting in a discontinuity in the
4.2.2 The maximum high dose rate to which the devices will
normal current flow in the device.
be exposed.
3.1.2.1 Discussion—This effect strongly depends on the
mode of operation and bias conditions. Temperature may also
5. Significance and Use
be a factor in damage to the device should latchup occur prior
5.1 The use of FXR radiation sources for the determination
to failure. Latchup is known to be temperature dependent.
of high dose-rate burnout in semiconductor devices is ad-
3.1.3 failure condition—a device is considered to have
dressed in this guide. The goal of this guide is to provide a
undergone burnout failure if the device experiences one of the
systematic approach to testing for burnout.
following conditions.
5.2 The different type of failure modes that are possible are
(1) functional failure—a device failure where the device under
defined and discussed in this guide. Specifically, failure can be
test, (DUT) fails the pre-irradiation functional tests following
defined by a change in device parameters, or by a catastrophic
exposure.
failure of the device.
5.3 This guide can be used to determine the survivability of
This guide is under the jurisdiction of Committee F-1on Electronics, and is the
a device, that is, that the device survives a predetermined level;
direct responsibility of Subcommittee F01.11 on Quality and Hardness Assurance.
or the guide can be used to determine the survival dose-rate
Current edition approved May 10, 1998. Published July 1998.
Annual Book of ASTM Standards, Vol. 12.02.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
F 1893
capability of the device. However, since this latter test is may be desirable to perform the burnout test using at least two
destructive, the minimum dose-rate level for failure must be different output conditions.
determined statistically. 6.5.3 Operating Voltage—Unless otherwise specified, test-
ing shall be performed using maximum operating voltages. The
6. Interferences
test setup shall be configured such that the transient power
6.1 There are several interferences that need to be consid-
supply photocurrent shall not be limited by the external circuit
ered when this test procedure is applied.
resistance or lead inductance. Power supply stiffening capaci-
6.2 Ionizing Dose Damage—Devices may be permanently
tors shall be included to keep the power supply voltage from
damaged by the accumulation of ionizing dose. This limits the
varying more than 10 % of the specified value during and after
number of radiation pulses that can be applied during burnout
the radiation pulse.
testing. The ionizing dose sensitivity depends on fabrication
6.6 Over-Stress—The high dose-rate burnout test should be
techniques and device technology. Metal oxide, semiconductor
considered destructive. Peak photocurrents in excess of 2 to 3
(MOS) devices are especially sensitive to ionizing dose dam-
amperes can occur during these tests. These large currents can
age, however, bipolar devices with oxide-isolated sidewalls
produce localized metalization, or semiconductor melting that
may also be affected by low levels of ionizing dose. The
is not readily detected by electrical testing, or both, but may
maximum ionizing total dose exposure of the test devices must
adversely affect device reliability. Devices that exceed manu-
not exceed fifty percent (50 %) of the typical ionizing dose
facturer’s absolute limits for current or power during burnout
failure level of the specific part type to ensure that a device
testing should not be used in high-reliability applications.
failure is caused by burnout, and not by an ionizing total dose.
6.7 Test Temperatures—Testing shall be performed at am-
6.2.1 Radiation Level Step Size—The size of the steps
bient temperature, or at a temperature agreed upon between the
between successive radiation levels limits the accuracy of the
parties to the test. If testing is performed in a vacuum,
determination of the burnout failure level.
overheating may be an issue, and temperature control is
6.3 Latchup—Some types of integrated circuits are suscep-
required.
tible to latchup during transient radiation exposure. If latchup
7. Apparatus
occurs, the device will not function correctly until power is
temporarily removed and reapplied. Permanent damage (burn- 7.1 General—The apparatus used for testing should include
out) may also occur during latchup, primarily caused by a as a minimum, the radiation source, dosimetry equipment, a
substantial increase in power supply current that leads to test circuit board, line drivers, cables and electrical instrumen-
increased power dissipation, localized heating, or both. tation to measure the transient response, provide bias, and
Latchup is temperature dependent and testing at elevated perform functional tests. Precautions shall be observed to
temperature is required to establish worst-case operating con- obtain an electrical measurement system with ample shielding,
ditions for latchup. Latchup testing is addressed elsewhere. satisfactory grounding, and low noise from electrical interfer-
6.4 Charge Build-up Damage—Damage to a device may ence or from the radiation environment.
occur due to direct electron irradiation of the DUT leads. When 7.1.1 Radiation Source—The most appropriate radiation
using direct electron irradiation of the DUT leads. When using source for high dose-rate burnout testing is a FXR machine.
direct electron irradiations, (see Section 7), all device leads The required dose rate for burnout cannot usually be achieved
must be shielded from the electron beam to reduce charge using an electron linear accelerator (LINAC) because LINACs
pickup that could cause abnormally large voltages to be typically cannot produce a sufficiently high dose rate over the
generated on internal circuitry and produce damage not related critical active area of the device under test. Linear accelerators
to ionizing dose-rate burnout. shall be used only with agreement of all parties to the test.
6.5 Bias and Load Conditions—The objective of the test is 7.1.2 Flash X-ray (Photon Mode)—The choice of facilities
to determine the dose-rate survivability of the test devices depends on the available dose rate as well as other factors
when tested under worst case conditions. including photon spectrum, pulse width and end-point energy.
6.5.1 Input Bias—Unless otherwise specified, the input bias The selection of the pulse width is affected by; (a), the dose
condition shall be chosen to provide the worst-case operating rate required, and (b), the ionizing dose accumulation per
conditions. For example, for digital devices, input pins that are pulse. Finally, the FXR end-point energy for the photon made
in the high state should be tied directly to the supply voltage. must be greater than 1 MeV to ensure device penetration.
For analog devices, input voltages generally should be at the 7.1.3 Flash X-ray (E-beam Mode)—An FXR operated in
maximum levels expected to be used. For both digital and the e-beam mode generally provides a higher dose rate than
analog devices, it is desirable to perform the burnout test using similar machines operated in the photon mode. However,
at least two different input conditions, such as minimum input testing in the e-beam mode requires that appropriate precau-
levels and maximum input levels, or alternately with half the tions be taken and special test fixtures be used to ensure
inputs tied high and the remaining tied low. meaningful results. The beam produces a large magnetic field,
6.5.2 Output Loading—Unless otherwise specified, the which may interfere with the instrumentation, and can induce
DUT outputs shall be chosen to provide the worst-case large circulating currents in device leads and metals. The beam
conditions for device operation. For digital devices, worst case also produces air ionization, induced charge on open leads, and
conditions should include maximum fan-out. For analog de- unwanted cable currents and voltages. E-beam testing is
vices, worst-case conditions should include maximum output generally performed with the DUT mounted in a vacuum to
voltage or load current. For both digital and analog devices, it reduce air ionization effects. Special dosimetry techniques are
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
F 1893
spectrum, the method used to calibrate the PIN diode, and the location of
required to ensure proper measurement of the dose. Finally, the
the PIN diode relative to the DUT.
FXR endpoint energy must be greater than 2 MeV to ensure
device penetration. some necessary precautions are:
7.2.4 Opti-chromic Dosimeters—Opti-chromic dosimeters
7.1.3.1 The electron beam must be constrained to the region
have many of the same advantages as TLDs. These devices are
that is to be irradiated. Support circuits and components must
relatively small, passive, inexpensive, and retain accurate dose
be shielded.
information for months between irradiation and measurement
7.1.3.2 The electron beam must be stopped within the test
of dose. The useful dose range of these devices is 400rd(Si) to
chamber and returned to the FXR to prevent unwanted currents
20Krd(Si). The device response is nearly linear with dose.
in cables and secondary radiation in the exposure room.
Opti-chromic dosimeters are calibrated in a Co cell using
7.1.3.3 All cables and wires must be protected from expo-
NIST traceable exposures. The dose response is independent of
sure to prevent extraneous currents. These currents may be
dose rate up to 10 rd(Si)/s.
caused by direct deposition of the beam in cables, or by
7.3 Test Circuit—The test circuit shall contain the device
magnetic coupling of the beams into the cable.
under test, wiring, and auxiliary components as required. It
7.1.3.4 All cables and cable entries must be shielded from
shall allow the application of power and bias signals at the
electromagnetic radiation caused by the firing of the FXR
device inputs and outputs. Power supply stiffening capacitors
machine.
shall be included to keep the power supply voltage from
7.1.3.5 An evacuated chamber for the test is required to
changing more than 10 % of its specified value during and after
reduce the effects of air ionization.
the radiation pulse (see 8.4). Capacitors placed across the
7.2 Dosimetry Equipment—Dosimetry equipment shall in-
supply voltage shall be located as close to the DUT as possible,
clude the following:
but shall not be exposed to the radiation beam. The test circuit
(a) a system for measuring ionizing dose, such as a
shall allow the device under test to be tested under worst case
thermoluminescent dosimeter (TLD) or calorimeter,
conditions (see 6.4).
(b) a pulse shape monitor, and
7.3.1 Materials—Test circuit materials and components
(c) a dosimeter that allows the dose rate to be determined
shall not cause attenuation or scattering, which will perturb the
from electronic measurements, for example, a positive intrinsic
uniformity of the beam at the test device position. The DUT
negative (PIN) detector, Faraday cup, secondary emission
shall be oriented so that its surface is perpendicular to the
monitor, or current transformer.
radiation beam.
NOTE 1—PIN represents a semiconductor structure consisting of highly 7.4 Cabling—Cabling shall be provided to connect the test
P and N regions on the two sides of an i
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