ASTM_F_1467_-_11.pdf

Designation:F146711Standard Guide forUse of an X-Ray Tester(10 keV Photons)in IonizingRadiation Effects Testing of Semiconductor Devices andMicrocircuits1This standard is issued under the fixed designation F1467;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,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 guide covers recommended procedures for the useof X-ray testers(that is,sources with a photon spectrum having10 keV mean photon energy and 50 keV maximum energy)in testing semiconductor discrete devices and integrated cir-cuits for effects from ionizing radiation.1.2 The X-ray tester may be appropriate for investigatingthe susceptibility of wafer level or delidded microelectronicdevices to ionizing radiation effects.It is not appropriate forinvestigating other radiation-induced effects such as single-event effects(SEE)or effects due to displacement damage.1.3 This guide focuses on radiation effects in metal oxidesemiconductor(MOS)circuit elements,either designed(as inMOS transistors)or parasitic(as in parasitic MOS elements inbipolar transistors).1.4 Information is given about appropriate comparison ofionizing radiation hardness results obtained with an X-raytester to those results obtained with cobalt-60 gamma irradia-tion.Several differences in radiation-induced effects caused bydifferences in the photon energies of the X-ray and cobalt-60gamma sources are evaluated.Quantitative estimates of themagnitude of these differences in effects,and other factors thatshould be considered in setting up test protocols,are presented.1.5 If a 10-keV X-ray tester is to be used for qualificationtesting or lot acceptance testing,it is recommended that suchtests be supported by cross checking with cobalt-60 gammairradiations.1.6 Comparisons of ionizing radiation hardness results ob-tained with an X-ray tester with results obtained with aLINAC,with protons,etc.are outside the scope of this guide.1.7 Current understanding of the differences between thephysical effects caused by X-ray and cobalt-60 gamma irradia-tions is used to provide an estimate of the ratio(number-of-holes-cobalt-60)/(number-of-holes-X-ray).Several cases aredefined where the differences in the effects caused by X-raysand cobalt-60 gammas are expected to be small.Other caseswhere the differences could potentially be as great as a factorof four are described.1.8 It should be recognized that neither X-ray testers norcobalt-60 gamma sources will provide,in general,an accuratesimulation of a specified system radiation environment.Theuse of either test source will require extrapolation to the effectsto be expected from the specified radiation environment.In thisguide,we discuss the differences between X-ray tester andcobalt-60 gamma effects.This discussion should be useful asbackground to the problem of extrapolation to effects expectedfrom a different radiation environment.However,the processof extrapolation to the expected real environment is treatedelsewhere(1,2).21.9 The time scale of an X-ray irradiation and measurementmay be much different than the irradiation time in the expecteddevice application.Information on time-dependent effects isgiven.1.10 Possible lateral spreading of the collimated X-raybeam beyond the desired irradiated region on a wafer is alsodiscussed.1.11 Information is given about recommended experimentalmethodology,dosimetry,and data interpretation.1.12 Radiation testing of semiconductor devices may pro-duce severe degradation of the electrical parameters of irradi-ated devices and should therefore be considered a destructivetest.1.13 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.14 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is the1This guide is under the jurisdiction ofASTM Committee F01 on Electronicsandis the direct responsibility of Subcommittee F01.11 on Nuclear and Space RadiationEffects.Current edition approved Oct.1,2011.Published October 2011.Originallyapproved in 1993.Last previous edition approved in 2005 as F1467-99(2005)1.DOI:10.1520/F1467-11.2The boldface numbers in parentheses refer to the list of references at the end ofthis guide.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 responsibility 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 Documents2.1 ASTM Standards:3E170 Terminology Relating to Radiation Measurements andDosimetryE666 Practice for Calculating Absorbed Dose From Gammaor X RadiationE668 Practice for Application of Thermoluminescence-Dosimetry(TLD)Systems for Determining AbsorbedDose in