1、Designation: F744M 10Standard Test Method forMeasuring Dose Rate Threshold for Upset of DigitalIntegrated Circuits (Metric)1This standard is issued under the fixed designation F744M; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the measurement of the thresh-old level of radiation dose rate that causes upset i
3、n digitalintegrated circuits under static operating conditions. The radia-tion source is either a flash X-ray machine (FXR) or an electronlinear accelerator (LINAC).1.2 The precision of the measurement depends on thehomogeneity of the radiation field and on the precision of theradiation dosimetry an
4、d the recording instrumentation.1.3 The test may be destructive either for further tests or forpurposes other than this test if the integrated circuit beingtested absorbs a total radiation dose exceeding some predeter-mined level. Because this level depends both on the kind ofintegrated circuit and
5、on the application, a specific value mustbe agreed upon by the parties to the test (6.8).1.4 Setup, calibration, and test circuit evaluation proceduresare included in this test method.1.5 Procedures for lot qualification and sampling are notincluded in this test method.1.6 Because of the variability
6、 of the response of differentdevice types, the initial dose rate for any specific test is notgiven in this test method but must be agreed upon by the partiesto the test.1.7 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.8 Thi
7、s standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Document
8、s2.1 ASTM Standards:2E665 Practice for Determining Absorbed Dose VersusDepth in Materials Exposed to the X-Ray Output of FlashX-Ray Machines3E666 Practice for CalculatingAbsorbed Dose From Gammaor X RadiationE668 Practice for Application of Thermoluminescence-Dosimetry (TLD) Systems for DeterminingA
9、bsorbed Dosein Radiation-Hardness Testing of Electronic DevicesE1894 Guide for Selecting Dosimetry Systems for Applica-tion in Pulsed X-Ray SourcesF526 Test Method for Measuring Dose for Use in LinearAccelerator Pulsed Radiation Effects Tests3. Terminology3.13.1.1 determined integrated circuitintegr
10、ated circuitwhose output is a unique function of the inputs; the outputchanges if and only if the input changes (for example, AND-and OR-gates).3.1.2 dose rateenergy absorbed per unit time and per unitmass by a given material from the radiation to which it isexposed.3.1.3 dose rate threshold for ups
11、etminimum dose rate thatcauses either: (1) the instantaneous output voltage of anoperating digital integrated circuit to be greater than thespecified maximum LOW value (for a LOW output level) orless than the specified minimum HIGH value (for a HIGHoutput level), or (2) a change of state of any stor
12、ed data.3.1.4 non-determined integrated circuitintegrated circuitwhose output or internal operating conditions are not uniquefunctions of the inputs (for example, flip-flops, shift registers,and RAMs).1This test method is under the jurisdiction of ASTM Committee F01 onElectronics and is the direct r
13、esponsibility of Subcommittee F01.11 on Nuclear andSpace Radiation Effects.Current edition approved May 1, 2010. Published June 2010. Originallyapproved in 1981. Last previous edition approved in 2003 as F744M 97 (2003).DOI: 10.1520/F0744M-10.2For referenced ASTM standards, visit the ASTM website, w
14、ww.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM Interna
15、tional, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Summary of Test Method4.1 The test device and suitable dosimeters are irradiated byeither an FXR or a linac. The test device is operating but understatic conditions. The output(s) of the test device and of
16、 thedosimeters are recorded.4.2 The dose rate is varied to determine the rate whichresults in upset of the test device.4.3 For the purposes of this test method, upset is consideredto be either of the following:4.3.1 An output voltage transient exceeding a predeter-mined value, or4.3.2 For devices ha
17、ving output logic levels which are notunique functions of the input logic levels, such as flip-flops, achange in the logic state of an output.4.3.3 For non-determined integrated circuits, a change ofstate of an internal storage element or node.4.4 A number of factors are not defined in this test met
18、hod,and must be agreed upon beforehand by the parties to the test:4.4.1 Total ionizing dose limit (see 1.3),4.4.2 Transient values defining an upset (see 4.3.1),4.4.3 Temperature at which the test is to be performed (see6.7),4.4.4 Details of the test circuit, including output loading,power supply le
19、vels, and other operating conditions (see 7.4,10.3, and 10.4),4.4.5 Choice of radiation pulse source (see 7.7),4.4.6 Radiation pulse width (see 7.7.2),4.4.7 Sampling (see 8.1),4.4.8 Need for total ionizing dose measurement (see 6.8,7.6, and 10.1),4.4.9 Desired precision of the upset threshold (see 1
20、0.8),and4.4.10 Initial dose rate (see 1.6 and 10.5).5. Significance and Use5.1 Digital integrated circuits are specified to operate withtheir inputs and outputs in either a logical 1 or a logical 0 state.The occurrence of signals having voltage levels not meetingthe specifications of either of these
21、 levels (an upset condition)may cause the generation and propagation of erroneous data ina digital system.5.2 Knowledge of the radiation dose rate that causes upsetin digital integrated circuits is essential for the design, produc-tion, and maintenance of electronic systems that are required toopera
22、te in the presence of pulsed radiation environments.6. Interferences6.1 Air IonizationA spurious component of the signalmeasured during a test can result from conduction through airionized by the radiation pulse. The source of such spuriouscontributions can be checked by measuring the signal whileir
23、radiating the test fixture in the absence of a test device. Airionization contributions to the observed signal are generallyproportional to the applied field, while those due to secondaryemission effects (6.2) are not. The effects of air ionizationexternal to the device may be minimized by coating e
24、xposedleads with a thick layer of paraffin, silicone rubber, or noncon-ductive enamel or by making the measurement in a vacuum.6.2 Secondary EmissionAnother spurious component ofthe measured signal can result from charge emission from, orcharge injection into, the test device and test circuit.4This
25、maybe minimized by shielding the surrounding circuitry andirradiating only the minimum area necessary to ensure irradia-tion of the test device. Reasonable estimates of the magnitudeto be expected of current resulting from secondary-emissioneffects can be made based on the area of metallic targetmat
26、erials irradiated (see Note 1). Values generally rangebetween 1011and 1010As/cm2Gy, but the use of a scatterplate with an intense beam may increase this current (7.7.2).NOTE 1For dose rates in excess of 108-Gy(Si)/s, the photocurrentsdeveloped by the package may dominate the device photocurrent. Car
27、eshould be taken in the interpretation of the measured photoresponse forthese high dose rates.6.3 OrientationThe effective dose to a semiconductorjunction can be altered by changing the orientation of the testdevice with respect to the irradiating beam. Most integratedcircuits may be considered “thi
28、n samples” (in terms of therange of the radiation). However, some devices may havecooling studs or thick-walled cases that can act to scatter theincident beam, thereby modifying the dose received by thesemiconductor chip. Care must be taken in the positioning ofsuch devices.6.4 Dose EnhancementHigh
29、atomic number materialsnear the active regions of the integrated circuit (package,metallization, die attach materials, etc.) can cause an enhanceddose to be delivered to the sensitive regions of the device whenit is irradiated with bremsstrahlung. Therefore, when an FXR isused as the radiation sourc
30、e, calculations should be performedto determine the possibility and extent of this effect.6.5 Electrical NoiseSince radiation test facilities are in-herent sources of r-f electrical noise, good noise-minimizingtechniques such as single-point ground, filtered d-c supplylines, etc., must be used in th
31、ese measurements.6.6 TemperatureDevice characteristics are dependent onjunction temperature; hence, the temperature of the test shouldbe controlled. Unless the parties to the test agree otherwise,measurements shall be made at room temperature (24 6 6C).6.7 Beam Homogeneity and Pulse-to-Pulse Repeata
32、bilityThe intensity of a beam from an FXR or a LINAC is likely tovary across its cross section. Since the pulse-shape monitor isplaced at a different location than the device under test, themeasured dose rate may be different from the dose rate towhich the device was exposed. The spatial distributio
33、n andintensity of the beam may also vary from pulse to pulse. Thebeam homogeneity and pulse-to-pulse repeatability associatedwith a particular radiation source should be established by athorough characterization of its beam prior to performing ameasurement.6.8 Total Ionizing DoseEach pulse of the ra
34、diation sourceimparts an ionizing dose to both the device under test and thedevice used for dosimetry. The total ionizing dose deposited in4Sawyer, J. A., and van Lint, V. A. J., “Calculations of High-Energy SecondaryElectron Emission,” Journal of Applied Physics, Vol 35, No. 6, June 1964, pp.170617
35、11.F744M 102a semiconductor device can change its operating characteris-tics. As a result, the response that is measured after severalpulses may be different from that characteristic of an unirra-diated device. Care should be exercised to ensure that the totalionizing dose delivered to the test devi
36、ce is less than theagreed-upon maximum value. Care must also be taken toensure that the characteristics of the dosimeter have notchanged due to the accumulated dose.7. Apparatus7.1 Regulated d-c Power SupplyA power supply withfloating outputs to produce the voltages required to bias theintegrated ci
37、rcuit under test.7.2 Recording DevicesA single dual-beam, or two single-beam oscilloscopes equipped with transient digitizers, record-ing media, and appropriate displays. The bandwidth capabili-ties of the recording devices shall be such that the radiationresponses of the integrated circuit and the
38、pulse-shape monitor(7.6) are accurately displayed and recorded.7.3 CablingTo adequately complete the connection of thetest circuit in the exposure area with the power supply andoscilloscopes in the data area. Shielded twisted pair or coaxialcables may be used to connect the power supplies to the bia
39、spoints of the test circuit; however, coaxial cables properlyterminated at the oscilloscope input are required for the signalleads.7.4 Test Circuit (see Fig. 1)Although the details of testcircuits for this test must vary depending on the kind ofintegrated circuit to be tested and on the specific par
40、ameters ofthe circuit which are to be measured, Fig. 1 provides theinformation necessary for the design of a test circuit for mostpurposes.The capacitor, C, provides an instantaneous source ofcurrent as may be required by the integrated circuit during theradiation pulse. Its value must be large enou
41、gh that thedecrease in the supply voltage during a pulse is less than 10 %.The capacitor, C, should be paralleled by a small (approxi-mately 0.01 F) low-inductance capacitor to ensure thatpossible inductive effects of the large capacitor are offset. Bothcapacitors must be located as close to the int
42、egrated circuitsocket as possible, consistent with the space needed forconnection of the current transformer and for any shielding thatmay be necessary. The switch, S, provides means to place theoutput of the integrated circuit (here a NAND gate) in either alogic LOW or a logic HIGH state. The arran
43、gement of thegrounding connections provides that only one ground exists, atthe point of measurement. This eliminates the possibility ofground loops and reduces the common-mode signals present atthe terminals of the measurement instruments. The resistor, R0,is the termination for the coaxial cable an
44、d has a value within2 % of the characteristic cable impedance.All unused inputs tothe test device are connected as agreed upon between theparties to the test. The output of the test device may be loaded,as agreed upon between the parties to the test. To preventloading of the output of the test devic
45、e by the coaxial cable,one may use a line driver that has a high input impedance andadequate bandwidth and voltage swing to reproduce accuratelyat the output end of the coaxial cable, the waveforms appearingat the line-driver input.7.5 Radiation Pulse-Shape MonitorUse one of the fol-lowing to develo
46、p a signal proportional to the dose ratedelivered to the test device:7.5.1 Fast Signal Diodein the circuit configuration of Fig.2. The resistors, R1, serve as high-frequency isolation and mustbe at least 20V. The capacitor, C, supplies the charge duringthe current transient; its value must be large
47、enough that thedecrease in voltage during a current pulse is less than 10 %.The capacitor, C, should be paralleled by a small (approxi-mately 0.01 F) low-inductance capacitor to ensure thatpossible inductive effects of the large capacitor are offset. Theresistor, R0, is to provide the proper termina
48、tion (within 62%)FIG. 1 Example of a Test Circuit for a NAND GateF744M 103for the coaxial cable used for the signal lead. This is thepreferred apparatus for this purpose.7.5.2 P-I-N Diodein the circuit configuration of Fig. 2 asdescribed in 7.5.1. Care should be taken to avoid saturationeffects.7.5.
49、3 PCDa photoconducive detector. Diamond or GaAsare typical PCD active materials. This active dosimeter has avery rapid, picoseconds response to the ionizing dose in theactive material.7.5.4 Current Transformer mounted on a collimator at theoutput window of the linear accelerator so that the primaryelectron beam passes through the opening of the transformerafter passing through the collimator. The current transformermust have a bandwidth sufficient to ensure that the currentsignal is accurately displayed. Rise time must be less than 10% of the pulse wi
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