1、Designation: F1190 11Standard Guide forNeutron Irradiation of Unbiased Electronic Components1This standard is issued under the fixed designation F1190; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A nu
2、mber in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide strictly applies only to the exposure ofunbiased silicon (Si) or gallium arsenide (GaAs) semiconduc-tor components (integrated
3、 circuits, transistors, and diodes) toneutron radiation from a nuclear reactor source to determinethe permanent damage in the components. Validated 1-MeVdisplacement damage functions codified in National Standardsare not currently available for other semiconductor materials.1.2 Elements of this guid
4、e, with the deviations noted, mayalso be applicable to the exposure of semiconductors com-prised of other materials except that validated 1-MeV displace-ment damage functions codified in National standards are notcurrently available.1.3 Only the conditions of exposure are addressed in thisguide. The
5、 effects of radiation on the test sample should bedetermined using appropriate electrical test methods.1.4 This guide addresses those issues and concerns pertain-ing to irradiations with reactor spectrum neutrons.1.5 System and subsystem exposures and test methods arenot included in this guide.1.6 T
6、his guide is applicable to irradiations conducted withthe reactor operating in either the pulsed or steady-state mode.The range of interest for neutron fluence in displacementdamage semiconductor testing range from approximately 109to 10161-MeV n/cm2.1.7 This guide does not address neutron-induced s
7、ingle ormultiple neutron event effects or transient annealing.1.8 This guide provides an alternative to Test Method1017.3, Neutron Displacement Testing, a component of MIL-STD-883 and MIL-STD-750. The Department of Defense hasrestricted use of these MIL-STDs to programs existing in 1995and earlier.1
8、.9 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 Do
9、cuments2.1 ASTM Standards:2E264 Test Method for Measuring Fast-Neutron ReactionRates by Radioactivation of NickelE265 Test Method for Measuring Reaction Rates and Fast-Neutron Fluences by Radioactivation of Sulfur-32E668 Practice for Application of Thermoluminescence-Dosimetry (TLD) Systems for Dete
10、rminingAbsorbed Dosein Radiation-Hardness Testing of Electronic DevicesE720 Guide for Selection and Use of Neutron Sensors forDetermining Neutron Spectra Employed in Radiation-Hardness Testing of ElectronicsE721 Guide for Determining Neutron Energy Spectra fromNeutron Sensors for Radiation-Hardness
11、Testing of Elec-tronicsE722 Practice for Characterizing Neutron Fluence Spectrain Terms of an Equivalent Monoenergetic Neutron Fluencefor Radiation-Hardness Testing of ElectronicsE1249 Practice for Minimizing Dosimetry Errors in Radia-tion Hardness Testing of Silicon Electronic Devices UsingCo-60 So
12、urcesE1250 Test Method for Application of Ionization Chambersto Assess the Low Energy Gamma Component ofCobalt-60 Irradiators Used in Radiation-Hardness Testingof Silicon Electronic DevicesE1854 Practice for Ensuring Test Consistency in Neutron-Induced Displacement Damage of Electronic PartsE1855 Te
13、st Method for Use of 2N2222A Silicon BipolarTransistors as Neutron Spectrum Sensors and Displace-ment Damage MonitorsE2450 Practice for Application of CaF2(Mn) Thermolumi-nescence Dosimeters in Mixed Neutron-Photon Environ-mentsF980 Guide for Measurement of Rapid Annealing ofNeutron-Induced Displace
14、ment Damage in Silicon Semi-conductor DevicesF1892 Guide for Ionizing Radiation (Total Dose) EffectsTesting of Semiconductor Devices1This guide is under the jurisdiction of ASTM Committee F01 on Electronicsand is the direct responsibility of Subcommittee F01.11 on Nuclear and SpaceRadiation Effects.
15、Current edition approved Oct. 1, 2011. Published October 2011. Originallyapproved in 1988. Last previous edition approved in 2005 as F119099(2005). DOI:10.1520/F1190-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annua
16、l 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.2.2 Other Documents:2.2.1 The Department of Defense publishes every fewyears
17、a compendium of nuclear reactor facilities that may besuitable for neutron irradiation of electronic components:DASIAC SR-94-009, April 1996, Guide to Nuclear Weap-ons Effects Simulation Facilities and Techniques32.3 The Office of the Federal Register, National Archivesand Records Administration pub
18、lishes several documents thatdelineate the regulatory requirements for handling and trans-porting radioactive semiconductor components:Code of Federal Regulations: Title 10 (Energy), Part 20,Standards for Protection Against Radiation4Code of Federal Regulations: Title 10 (Energy), Part 30,Rules of G
19、eneral Applicability to Domestic Licensing ofByproduct Material4Code of Federal Regulations: Title 49 (Transportation),Parts 100 to 17743. Terminology3.1 Definitions:3.1.1 1-MeV equivalent neutron fluence Feq, 1 MeV, Sithisexpression is used by the radiation-hardness testing communityto characterize
20、 an incident energy-fluence spectrum, F(E), interms of monoenergetic neutrons at a specific energy, Eref=1MeV, required to produce the same displacement damage in aspecific irradiated material, denoted by the subscript as “matl”(see Practice E722 for details).3.1.1.1 DiscussionHistorically, the mate
21、rial has been as-sumed to be silicon (Si). The emergence of gallium arsenide(GaAs) as a significant alternate semiconductor material,whose radiation damage effects mechanisms differ substan-tially from Si based devices, requires that future use of the1-MeV equivalent fluence expression include the e
22、xplicitspecification of the irradiation semiconductor material.3.1.2 equivalent monoenergetic neutron fluence(Feq,Eref, matl)an equivalent monoenergetic neutron fluencethat characterizes an incident energy-fluence spectrum, F(E),in terms of the fluence of monoenergetic neutrons at a specificenergy,
23、Eref, required to produce the same displacement dam-age in a specified irradiated material, matl (see Practice E722for details).3.1.2.1 DiscussionThe appropriate expressions for com-monly used 1-MeV equivalent fluence are Feq, 1 MeV, Siforsilicon semiconductor devices and Feq, 1 MeV, GaAsfor gallium
24、arsenide based devices. See Practice E722 for a more thoroughtreatment of the meaning and significant limitations imposedon the use of these expressions.3.1.3 silicon damage equivalent (SDE)expression syn-onymous with “1-MeV(Si) equivalent fluence in silicon.”4. Summary of Guide4.1 Evaluation of neu
25、tron radiation-induced damage insemiconductor components and circuits requires that the fol-lowing steps be taken:4.1.1 Select a suitable reactor facility where the radiationenvironment and exposure geometry desired are both availableand currently characterized (within the last 15 months). Prac-tice
26、 E1854 contains detailed guidance to assist the user inselecting a reactor facility that is certified to be adequatelycalibrated.4.1.2 Prepare test plan and fixtures,4.1.3 Conduct pre-irradiation electrical test of the testsample,4.1.4 Expose test sample and dosimeters,4.1.5 Retrieve irradiated test
27、 sample,4.1.6 Read dosimeters,4.1.7 Conduct post-irradiation electrical tests, and4.1.8 Repeat 4.1.4 through 4.1.7 until the desired cumula-tive fluence is achieved or until degradation of the test devicewill not allow any further useful data to be taken.4.2 Operations addressed in this guide are on
28、ly thoserelating to reactor facility selection, irradiation procedure andfixture development, positioning and exposure of the testsample, and shipment of the irradiated samples back to theparent facility. Dosimetry methods are covered in existingASTM standards referenced in Section 2, and many pre-
29、andpost-exposure electrical measurement procedures are containedin the literature. Dosimetry is usually supplied by the reactorfacility, see Practice E1854.5. Significance and Use5.1 Semiconductor devices can be permanently damaged byreactor spectrum neutrons (1, 2)5. The effect of such damage onthe
30、 performance of an electronic component can be determinedby measuring the components electrical characteristics beforeand after exposure to fast neutrons in the neutron fluence rangeof interest. The resulting data can be utilized in the design ofelectronic circuits that are tolerant of the degradati
31、on exhibitedby that component.5.2 This guide provides a method by which the exposure ofsilicon and gallium arsenide semiconductor devices to neutronirradiation may be performed in a manner that is repeatable andwhich will allow comparison to be made of data taken atdifferent facilities.5.3 For semic
32、onductors other than silicon and galliumarsenide, applicable validated 1-MeV damage functions are notavailable in codified National standards. In the absence of avalidated 1-MeV damage function, the non-ionizing energyloss (NIEL) or the displacement kerma, as a function incidentneutron energy, norma
33、lized to the response in the 1 MeVenergy region, may be used as an approximation. See PracticeE722 for a description of the method used to determine thedamage functions in Si and GaAs (3).6. Interferences6.1 Gamma Effects:6.1.1 All nuclear reactors produce gamma radiation coinci-dent with the produc
34、tion of neutrons. Prompt gamma rays are3Available from Defense Special Weapons Agency, Washington, DC 20305-1000.4Available from the Superintendent of Documents, U.S. Government PrintingOffice, Washington, DC 20402.5The boldface numbers in parentheses refer to a list of references at the end ofthis
35、standard.F1190 112produced directly in the fission process, from neutron trans-mutation reactions with reactor support materials and testobjects. Delayed gamma rays are emitted by fission productsand activated materials. Furthermore, these gamma rays canproduce secondary gamma rays and fluorescence
36、photons inreactor fuel, moderator, and surrounding materials. Sincedegradation in piece part performance may be produced bygamma rays as well as neutrons, and because of the softerphoton spectra dose enhancement may be a problem. If aseparation of neutron (n) and gamma ray (g) degradation isdesired,
37、 either the n/g ratio must be increased to the point atwhich gamma effects are negligible or the test sample degra-dation must first be characterized in a “pure” gamma rayenvironment and one must have a basis for believing that thedamage mode of concern does not exhibit any synergy betweenthe neutro
38、n and gamma response. The use of such data from agamma ray exposure to separate neutron and gamma effectsobtained during a neutron exposure may be a complex task. Ifthis approach is taken, Guide F1892 should be used as areference. Guides E1249 and E1250 should be used to addressdose enhancement issu
39、es.6.1.2 TRIGA-type reactors (Training Research and Isotopeproduction reactor manufactured by General Atomics) delivergamma dose during neutron irradiations that can vary consid-erably depending on the immediately preceding operatinghistory of the reactor. A TRIGA-type reactor that has beenoperating
40、 at a high power level for an extended period prior tothe semiconductor component neutron irradiation will containa larger fission product inventory that will contribute signifi-cantly higher gamma dose than a reactor that has had no recenthigh level operations. The experimenter must determine thema
41、ximum gamma dose his experiment can tolerate, and advisethe facility operator to provide sufficient shielding to meet thislimit.6.2 Temperature EffectsAnnealing of neutron damage isenhanced at elevated temperatures. Elevated temperatures mayoccur during irradiation, transportation, storage, or elect
42、ricalcharacterization of the test devices.6.3 Dosimetry ErrorsNeutron fluence is typically re-ported in terms of an equivalent 1-MeV monoenergetic neutronfluence in the specified irradiated material (Feq, 1 MeV, SiorFeq, 1 MeV, GaAs) in units of neutrons per square centimeter.ASTM guidelines and sta
43、ndards exist for calculating this valuefrom measured reactor characteristics. However, reactor facili-ties may not routinely re-measure the neutron spectrum, (usingGuide E720 and Method E721) at the test sample exposuresites. A currently valid determination of the neutron spectrumis needed to provid
44、e the essential data to accurately ascertainthe equivalent 1-MeV monoenergetic neutron fluence in thespecified irradiated material. Lack of this critical data canresult in substantial error. Therefore, the experimenter mustrequest a current valid determination of the 1-MeV equivalentfluence in silic
45、on or GaAs, as needed, from the reactor facilityoperator. This may require a re-characterization of the reactortest facility, or the particular test configuration. Practice E1854discusses the roles of the facility, dosimetrist, and user.6.4 Recoil Ionization EffectsIonization effects fromneutron-ind
46、uced recoils of the lattice atoms within a semicon-ductor device may be significant for some device types at somereactor configurations, although under normal conditions, ion-ization due to the gamma radiation from the source will bemuch greater than the ionization from neutron-induced recoils.6.5 T
47、est Configuration EffectsExtraneous materials in thevicinity of the test specimens can modify the radiation envi-ronment at the test sample location. Both the neutron spectrumand the gamma field can be altered by the presence of suchmaterial even if these materials are not directly interposedbetween
48、 the reactor core and the test devices.6.6 Thermal Neutron EffectsFast Burst Reactor (FBR)neutron spectra have a small thermal neutron component;however, TRIGA reactors inherently produce a very largethermal neutron flux from the water moderation of the fissionneutrons. Neutrons interact with the ma
49、terials of the devicesbeing irradiated causing them to become radioactive. Thermalneutrons generally induce higher levels of radioactivity. As aconsequence, parts irradiated to moderate or high fluencelevels at TRIGA reactors should not be handled or measuredsoon after exposure. It is therefore common practice at TRIGAreactors to shield test parts from the thermal neutrons withborated polyethylene or cadmium shields. Cadmium capture ofthermal neutrons produces more gamma rays than boroncapture, thus producing a lower n/g ratio when such a shield isused. In addition, wherea
