1、Designation: F773M 10Standard Practice forMeasuring Dose Rate Response of Linear IntegratedCircuits (Metric)1This standard is issued under the fixed designation F773M; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t 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 practice covers the measurement of the response oflinear integrated circuits, under given operating conditions, topu
3、lsed ionizing radiation. The response may be either transientor more lasting, such as latchup. The radiation source is eithera flash X-ray machine (FXR) or an electron linear accelerator(LINAC).1.2 The precision of the measurement depends on thehomogeneity of the radiation field and on the precision
4、 of theradiation dosimetry and the recording instrumentation.1.3 The test may be considered to be destructive either forfurther tests or for other purposes if the total radiation ionizingdose exceeds some predetermined level or if the part shouldlatch up. Because this level depends both on the kind
5、ofintegrated circuit and on the application, a specific value mustbe agreed upon by the parties to the test. (See 6.10.)1.4 Setup, calibration, and test circuit evaluation proceduresare included in this practice.1.5 Procedures for lot qualification and sampling are notincluded in this practice.1.6 B
6、ecause response varies with different device types, thedose rate range for any specific test is not given in this practicebut must be agreed upon by the parties to 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
7、 This 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 Docu
8、ments2.1 ASTM Standards:2E666 Practice for CalculatingAbsorbed Dose From Gammaor X RadiationE668 Practice for Application of Thermoluminescence-Dosimetry (TLD) Systems for DeterminingAbsorbed Dosein Radiation-Hardness Testing of Electronic DevicesE1894 Guide for Selecting Dosimetry Systems for Appli
9、ca-tion in Pulsed X-Ray SourcesF526 Test Method for Measuring Dose for Use in LinearAccelerator Pulsed Radiation Effects Tests3. Terminology3.1 Definitions:3.1.1 dose rateenergy absorbed per unit time and per unitmass by a given material from the radiation to which it isexposed.3.1.2 dose rate induc
10、ed latchupRegenerative device ac-tion in which a parasitic region (e.g., a four (4) layer p-n-p-n orn-p-n-p path) is turned on by a photocurrent generated by apulse of ionizing radiation and remains on for an indefiniteperiod of time after the photocurrent subsides. The device willremain latched as
11、long as the power supply delivers voltagegreater than the holding voltage and current greater than theholding current. Latchup may disrupt normal circuit operationin some portion of the circuits, and may also cause catastrophicfailure due to local heating of semiconductor regions, metalli-zations or
12、 bond wires.3.1.2.1 DiscussionLatchup is very sensitive at highervoltages and maximum voltage.The observance of latchup willbe seen readily if these operation conditions are achieved.3.1.3 dose rate responsethe change that occurs in anobserved characteristic of an operating linear integrated circuit
13、induced by a radiation pulse of a given dose rate.3.1.4 latchup windowA latchup window is the phenom-enon in which a device exhibits latchup in a specific range of1This practice is under the jurisdiction of ASTM Committee F01 on Electronicsand is the direct responsibility of Subcommittee F01.11 on N
14、uclear and SpaceRadiation Effects.Current edition approved May 1, 2010. Published June 2010. Originallyapproved in 1982. Last previous edition approved in 2003 as F773M 96 (2003).DOI: 10.1520/F0773M-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Serv
15、ice at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.dose rates. Above and below this range, the
16、device does notlatchup. A device may exhibit more than one latchup window.This phenomenon has been observed for some complimentarymetal-oxide-semiconductor (CMOS) logic devices, oxide side-wall logic and large scale integration (LSI) memories and mayoccur in the other devices.3.1.5 upset thresholdTh
17、e minimum dose rate at which thedevice upsets. However, the reported measured upset thresholdshall be the maximum dose rate at which the device does notupset and which the transient disturbance of the outputwaveform and or supply current remains within the specifiedlimits.4. Summary of Practice4.1 T
18、he test device and suitable dosimeters are irradiated bya pulse from either an FXR or a LINAC while the test deviceis operating under agreed-upon conditions. The responses ofthe test device and of the dosimeters are recorded.4.2 The response of the test device to dose rate is recordedover a specifie
19、d dose rate range.4.3 A number of factors are not defined in this practice, andmust be agreed upon beforehand by the parties to the test.4.3.1 Total dose limit (see 1.3),4.3.2 Electrical parameters of the test device whose re-sponses are to be measured (see 10.10),4.3.3 Temperature at which the test
20、 is to be performed (see6.7),4.3.4 Details of the test circuit, including output loading,power supply levels, and other operating conditions (see 7.4and 10.3),4.3.5 Choice of radiation pulse source (see 6.9 and 7.9),4.3.6 Pulse width (see 6.9 and 7.9.2),4.3.7 Sampling (see 8.1),4.3.8 Need for total
21、ionizing dose measurement (see 6.10,7.8, and 10.1.1),4.3.9 An irradiation plan which includes the dose rate rangeand the minimum number of dose rate values to be used in thatrange (see 10.6 and 10.9), and4.3.10 Appropriate functional test (see 10.4 and 10.8).5. Significance and Use5.1 There are many
22、 kinds of linear integrated circuits. Anygiven linear integrated circuit may be used in a variety of waysand under various operating conditions within the limits ofperformance specified by the manufacturer. The procedures ofthis practice provide a standardized way to measure thedose-rate response of
23、 a linear integrated circuit, under operat-ing conditions similar to those of the intended application,when the circuit is exposed to pulsed ionizing radiation.5.2 Knowledge of the responses of linear integrated circuitsto radiation pulses is essential for the design, production, andmaintenance of e
24、lectronic systems that are required to operatein 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. Such spurious contributions canbe checked by
25、 measuring the signal while irradiating the testfixture in the absence of a test device. Air ionization contribu-tions to the observed signal are generally proportional toapplied field, while those due to secondary emission effects(6.2) are not. The effects of air ionization external to the devicema
26、y be minimized by coating exposed leads with a thick layerof paraffin, silicone rubber, or nonconductive enamel, or bymaking 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 devi
27、ce and test circuit.3This 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 expectedmagnitude of current resulting from secondary-emission effectscan be made based on the area o
28、f metallic target materialsirradiated.NOTE 1For dose rates in excess of 108Gy (Si)/s, the photocurrentsdeveloped by the package may dominate the device photocurrent. Careshould be taken in the interpretation of the measured photoresponse forthese high dose rates.Values of current density per unit do
29、se rate generally rangebetween 1011and 1010A/cm2per Gy(Si)/s. The use of ascatter plate (7.9.2) may increase these values.6.3 OrientationThe effective ionizing dose to a semicon-ductor junction can be altered by changing the orientation ofthe test device with respect to the irradiating beam. Mostint
30、egrated circuits may be considered “thin samples” (in termsof the range of the radiation). However, some devices mayhave cooling studs or thick-walled cases that can act to scatterthe incident beam, thereby modifying the dose received by thesemiconductor chip. Position such devices carefully with th
31、edie normal to the beam.6.4 Dose EnhancementHigh atomic number materialsnear the active regions of the integrated circuit (package,metallization, die attach materials, etc.) can deliver an en-hanced dose to the sensitive regions of the device due tosecondary electron emission from the high atomic nu
32、mbermaterial when it is irradiated with an FXR. The possibility andextent of this effect should be considered.6.5 Electrical NoiseSince radiation test facilities are in-herent sources of r-f noise, good noise-minimizing techniquessuch as single-point ground, filtered dc supply lines, etc., mustbe us
33、ed in these measurements (see Fig. 1).6.6 DosimetryAccurate, reproducible calibration of dose-rate monitors is difficult. For this reason, dosimetry is apt toprovide the single most substantial source of error in dose-ratedeterminations.6.7 TemperatureDevice characteristics are dependent onjunction
34、temperature; hence, the temperature of the test shouldbe controlled. Unless otherwise agreed upon by the parties tothe test, dose rate testing shall be performed at 24 6 6C.(Temperature should be specified in the test plan or testprocedure).3Sawyer, J. A., and van Lint, V. A. J., “Calculations of Hi
35、gh-Energy SecondaryElectron Emission,” Journal of Applied Physics, Vol 35, No. 6, June 1964, pp.17061711.F773M 1026.8 Beam Homogeneity and Pulse-to-Pulse RepeatabilityThe 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
36、 different location than the device under test, themeasured dose rate may be different from the dose rate towhich the device was exposed. The spatial distribution andintensity of the beam may also vary from pulse to pulse. Thebeam homogeneity and pulse-to-pulse repeatability associatedwith a particu
37、lar radiation source should be established by athorough characterization of its beam prior to performing ameasurement.6.9 Pulse WidthThe response observed in a dose rate testmay be dependent on the width of the radiation pulse. This factmust be considered when selecting a radiation source, or whenco
38、mparing data taken at different times or at different radiationtest facilities.6.10 Total Ionizing DoseEach pulse of the radiationsource imparts an ionizing dose to both the device under testand the device used for dosimetry. The total ionizing doseaccumulated in a semiconductor device will cause pe
39、rmanentdamage which can change its operating characteristics. As aresult, the response that is measured after several pulses maybe different from that characteristic of an unirradiated device.Care should be exercised to ensure that the total ionizing dosedelivered to the test device is less than the
40、 agreed-uponmaximum value. Care must also be taken to ensure that thecharacteristics of the dosimeter have not changed due to theaccumulated dose.7. Apparatus7.1 Regulated DC Power Supplies with floating outputs toproduce the voltages required to bias the integrated circuitunder test.7.2 Recording D
41、evicessuch as oscilloscopes equippedwith cameras, transient digitizers with appropriate displays, orother suitable instruments. The bandwidth capabilities of therecording devices shall be such that the radiation responses ofthe integrated circuit and the pulse-shape monitor (7.6) areaccurately displ
42、ayed and recorded.NOTE 2Depending on the kind of measurement, dc instruments,spectrum analyzers, current transformers, or other instruments may berequired to measure and record the response of the test device.7.3 Cabling to complete adequately the connection of thetest circuit in the exposure area w
43、ith the power supply andrecording devices in the data area. Shielded twisted pair orcoaxial cables may be used to connect the power supplies to thebias points of the test circuit; however, coaxial cables properlyterminated at the recording device inputs are required for thesignal leads.7.4 Test Circ
44、uit, as shown in Fig. 1. Although the details oftest circuits for this test must vary depending on the kind ofelectronic component tested and on the specific electricalparameters of the test device to be measured, the example ofFig. 1 provides the information necessary for the design of atest circui
45、t for most purposes. The capacitor, C1(typically 10F), provides an instantaneous source of current as may berequired by the test device during the radiation pulse. Its valuemust be large enough that the decrease in the supply voltageduring a pulse is less than 10 %. Capacitor C1should be placedin pa
46、rallel with a small (approximately 0.1 F) low-inductancecapacitor, C2, to ensure that possible inductive effects of thelarge capacitor are offset. Both capacitors must be located asclose to the test device as possible, consistent with the spaceneeded for any shielding that may be necessary. The arra
47、nge-ment of the grounding connections provides that there are noground loops and that only one ground exists. This reducesboth the possibility of ground loops and common-mode signalspresent at the terminals of the measurement instruments. Theresistors, R0, are terminations for the coaxial cables, an
48、d havevalues within2%ofthecharacteristic impedances of theirrespective cables. All unused inputs to the test device areconnected as agreed upon by the parties to the test. Theoutput(s) of the test device may be loaded, as agreed upon byFIG. 1 Example of a Test CircuitF773M 103the parties to the test
49、. To prevent loading of the output of thetest device by the coaxial cable, line drivers having a high inputimpedance and adequate bandwidth, linearity, and dynamicrange may be used to reproduce accurately at the output end ofthe coaxial cable the waveforms appearing at the line driverinputs.7.5 Signal Sourcesas required to provide the agreed-uponoperating conditions of the test device and to perform suitablefunctional tests.7.6 Radiation Pulse-Shape MonitorOne of the followingto develop a signal proportional to the dose rate delivered to thetest device.7
