1、Designation: F 1710 08Standard Test Method forTrace Metallic Impurities in Electronic Grade Titanium byHigh Mass-Resolution Glow Discharge Mass Spectrometer1This standard is issued under the fixed designation F 1710; the number immediately following the designation indicates the year oforiginal adop
2、tion 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 test method covers the determination of concentra-tions of trace me
3、tallic impurities in high purity titanium.1.2 This test method pertains to analysis by magnetic-sectorglow discharge mass spectrometer (GDMS).1.3 The titanium matrix must be 99.9 weight % (3N-grade)pure, or purer, with respect to metallic impurities. There mustbe no major alloy constituent, for exam
4、ple, aluminum or iron,greater than 1000 weight ppm in concentration.1.4 This test method does not include all the informationneeded to complete GDMS analyses. Sophisticated computer-controlled laboratory equipment skillfully used by an experi-enced operator is required to achieve the required sensit
5、ivity.This test method does cover the particular factors (for example,specimen preparation, setting of relative sensitivity factors,determination of sensitivity limits, etc.) known by the respon-sible technical committee to effect the reliability of high puritytitanium analyses.1.5 This standard doe
6、s 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 Documents2.1 ASTM Stan
7、dards:2E 135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related MaterialsE 173 Practice for Conducting Interlaboratory Studies ofMethods for Chemical Analysis of Metals3E 180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-c
8、ialty ChemicalsE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE 1257 Guide for Evaluating Grinding Materials Used forSurface Preparation in Spectrochemical Analysis3. Terminology3.1 Terminology in this test method is consistent withTerminology E 135.
9、 Required terminology specific to this testmethod, not covered in Terminology E 135, is indicated in 3.2.3.2 Definitions:3.2.1 campaigna series of analyses of similar specimensperformed in the same manner in one working session, usingone GDMS setup.3.2.1.1 DiscussionAs a practical matter, cleaning o
10、f theion source specimen cell is often the boundary event separatingone analysis campaign from the next.3.2.2 reference samplematerial accepted as suitable foruse as a calibration/sensitivity reference standard by all partiesconcerned with the analyses.3.2.3 specimena suitably sized piece cut from a
11、 referenceor test sample, prepared for installation in the GDMS ionsource, and analyzed.3.2.4 test samplematerial titanium to be analyzed fortrace metallic impurities by this GDMS method.3.2.4.1 DiscussionGenerally the test sample is extractedfrom a larger batch (lot, casting) of product and is inte
12、nded tobe representative of the batch.4. Summary of the Test Method4.1 A specimen is mounted as the cathode in a plasmadischarge cell. Atoms subsequently sputtered from the speci-men surface are ionized, and then focused as an ion beamthrough a double-focusing magnetic-sector mass separationapparatu
13、s. The mass spectrum, that is, the ion current, iscollected as magnetic field or acceleration voltage, or both, isscanned.4.2 The ion current of an isotope at mass Miis the totalmeasured current, less contributions from all other interferingsources. Portions of the measured current may originate fro
14、mthe ion detector alone (detector noise). Portions may be due toincompletely mass resolved ions of an isotope or molecule withmass close to, but not identical with, Mi. In all such instances1This test method is under the jurisdiction of ASTM Committee F01 onElectronics and is the direct responsibili
15、ty of Subcommittee F01.17 on SputterMetallization.Current edition approved June 15, 2008. Published July 2008. Originallyapproved in 1996. Last previous edition approved in 2002 as F 1710 97(02).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at
16、serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.the interfering contributions must be es
17、timated and subtractedfrom the measured signal.4.2.1 If the source of interfering contributions to the mea-sured ion current at Micannot be determined unambiguously,the measured current less the interfering contributions fromidentified sources constitutes an upper bound of the detectionlimit for the
18、 current due to the isotope.4.3 The composition of the test specimen is calculated fromthe mass spectrum by applying a relative sensitivity factor(RSF(X/M) for each contaminant element, X, compared to thematrix element, M. RSFs are determined in a separate analysisof a reference material performed u
19、nder the same analyticalconditions, source configuration, and operating protocol as forthe test specimen.4.4 The relative concentrations of elements X and Y arecalculated from the relative isotopic ion currents I(Xi) and I(Yj)in the mass spectrum, adjusted for the appropriate isotopicabundance facto
20、rs (A(Xi), A(Yj) and RSFs. I(Xi) and I(Yj) referto the measured ion current from isotopes Xiand Yj, respec-tively, of atomic species X and Y as follows:X/Y 5 RSFX/M!/RSFY/M!3 AYj!/AXi! 3 IXi!/IYj!, (1)where (X)/(Y) is the concentration ratio of atomic species Xto species Y. If species Y is taken to
21、be the titanium matrix(RSF(M/M) = 1.0), (X) is (with only very small error for puremetal matrices) the absolute impurity concentration of X.5. Significance and Use5.1 This test method is intended for application in thesemiconductor industry for evaluating the purity of materials(for example, sputter
22、ing targets, evaporation sources) used inthin film metallization processes. This test method may beuseful in additional applications, not envisioned by the respon-sible technical committee, as agreed upon between the partiesconcerned.5.2 This test method is intended for use by GDMS analystsin variou
23、s laboratories for unifying the protocol and parametersfor determining trace impurities in pure titanium. The objectiveis to improve laboratory to laboratory agreement of analysisdata. This test method is also directed to the users of GDMSanalyses as an aid to understanding the determination method,
24、and the significance and reliability of reported GDMS data.5.3 For most metallic species the detection limit for routineanalysis is on the order of 0.01 weight ppm. With specialprecautions detection limits to sub-ppb levels are possible.5.4 This test method may be used as a referee method forproduce
25、rs and users of electronic-grade titanium materials.6. Apparatus6.1 Glow Discharge Mass Spectrometer, with mass resolu-tion greater than 3500, and associated equipment and supplies.The GDMS must be fitted with an ion source specimen cell thatis cooled by liquid nitrogen, Peltier cooled, or cooled by
26、 anequivalent method.6.2 Machining Apparatus, capable of preparing specimensand reference samples in the required geometry and withsmooth surfaces.7. Reagents and Materials7.1 Reagent and High Purity Grade Reagents, as required(MeOH, HNO3,HF,H2O2).7.2 Demineralized Water.7.3 Tantalum Reference Sampl
27、e.7.4 Titanium Reference Sample.7.4.1 To the extent available, titanium reference materialsshall be used to produce the GDMS relative sensitivity factorsfor the various elements being determined (Table 1).7.4.2 As necessary, non-titanium reference materials may beused to produce the GDMS relative se
28、nsitivity factors for thevarious elements being determined.7.4.3 Reference materials should be homogeneous and freeof cracks or porosity.7.4.4 At least two reference materials are required to estab-lish the relative sensitivity factors, including one nominally99.999 % pure (5N-grade) or better titan
29、ium metal to establishthe background contribution in analyses.7.4.5 The concentration of each analyte for relative sensi-tivity factor determination should be a factor of 100 greaterthan the detection limit determined using a nominally99.999 % pure (5N-grade) or better titanium specimen, but lesstha
30、n 100 ppmw.7.4.6 To meet expected analysis precision, it is necessarythat specimens of reference and test material present the samesize and configuration (shape and exposed length) in the glowdischarge ion source, with a tolerance of 0.2 mm in diameterand 0.5 mm in the distance of specimen to cell i
31、on exit slit.8. Preparation of Reference Standards and TestSpecimens8.1 The surface of the parent material must not be includedin the specimen.8.2 The machined surface of the specimen must be cleanedby chemical etching immediately prior to mounting the speci-men and inserting it into the glow discha
32、rge ion source.8.2.1 In order to obtain a representative bulk composition ina reasonable analysis time, surface cleaning must remove allcontaminants without altering the composition of the specimensurface.8.2.2 To minimize the possibility of contamination, cleaneach specimen separately immediately p
33、rior to mounting in theglow discharge ion source.8.2.3 Prepare and use etching solutions in a clean containerinsoluble in the contained solution.8.2.4 Useful etching solutions are HNO3:HF:3:1 orHNO3:HF:H2O2: :1:1:1 or H2O:HNO3:HF:H2O2:20:5:5:4(double etched), etching until smooth, clean metal is exp
34、osedover the entire surface.8.2.5 Immediately after cleaning, wash the specimen withhigh purity rinses and thoroughly dry the specimen in thelaboratory environment.NOTE 1Examples of acceptable high purity rinses are very large scaleintegration (VLSI) grade methanol and distilled water.8.3 Immediatel
35、y mount and insert the specimen into theglow discharge ion source, minimizing exposure of thecleaned, rinsed, specimen surface to the laboratory environ-ment.F 1710 0828.3.1 As necessary, use a noncontacting gage when mount-ing specimens in the analysis cell specimen holder to ensurethe proper sampl
36、e configuration in the glow discharge cell (see7.4.6).8.4 Sputter etch the specimen surface in the glow dischargeplasma for a period of time before data acquisition (12.3)toensure the cleanliness of the surface. Pre-analysis sputteringconditions can be limited by the need to maintain sampleintegrity
37、. If sputter cleaning and analysis are carried out underdifferent plasma conditions, accuracy should be established forthe analytical protocol adopted and elements measured.9. Preparation of the GDMS Apparatus9.1 The ultimate background pressure in the ion sourcechamber should be less than 1 3 106to
38、rr before operation.The background pressure in the mass analyzer should be lessthan 5 3 107torr during operation.9.2 The glow discharge ion source must be cooled to nearliquid nitrogen temperature.9.3 The GDMS instrument must be accurately mass cali-brated prior to measurements.9.4 The GDMS instrume
39、nt must be adjusted to the appro-priate mass peak shape and mass resolving power for therequired analysis.9.5 If the instrument uses different ion collectors to measureion currents during the same analysis, the measurement effi-ciency of each detector relative to the others should bedetermined at le
40、ast weekly.9.5.1 If both Faraday cup collector for ion current measure-ment and ion counting detectors are used during the sameanalysis, the ion counting efficiency (ICE) must be determinedprior to each campaign of specimen analyses using the follow-ing or equivalent procedures:9.5.1.1 Using a speci
41、men of tantalum, measure the ioncurrent from the major isotope (181Ta) using the ion currentFaraday cup detector, and measure the ion current from theminor isotope (180Ta) using the ion counting detector, with careto avoid ion counting losses due to ion-counting system deadtimes. The counting loss s
42、hould be 1 % or less.9.5.1.2 The ion counting efficiency is calculated by multi-plying the ratio of the180Ta ion current to the181Ta ion currentby the181Ta/180Ta isotopic ratio. The result of this calculationis the ion counting detector efficiency (ICE).9.5.1.3 Apply the ICE as a correction to all i
43、on currentmeasurements from the ion counting detector obtained inanalyses by dividing the ion current by the ICE factor.10. Instrument Quality Control10.1 A well-characterized specimen must be run on aregular basis to demonstrate the capability of the GDMSsystem as a whole for the required analyses.
44、10.2 A recommended procedure is the measurement of therelative ion currents of selected analytes and the matrixelement in titanium or tantalum reference samples.10.3 Plot validation analysis data from at least five elementswith historic values in statistical process control (SPC) chartformat to demo
45、nstrate that the analysis process is in statisticalTABLE 1 Suite of Impurity Elements to be Analyzed, withAppropriate Isotope SelectionNOTE 1Establish RSFs for the following suite of elements, using theindicated isotopes for establishing RSF values and for performinganalyses of test specimens.NOTE 2
46、This selection of isotopes minimizes significant interferences(see Annex A1.). Additional species may be determined and reported, asagreed upon by all parties concerned with the analyses. Other isotopes canbe selected to assist mass spectrum peak identification or for otherpurposes.LithiumBerylliumB
47、oronCarbonNitrogenOxygenFluorineSodiumMagnesiumAluminumSiliconPhophorusSulfurChlorinePotassiumCalciumScandiumTitaniumVanadiumChromiumManganeseIronCobaltNickelCopperZincGalliumGermaniumArsenicSeleniumBromineRubidiumYttriumZirconiumNiobiumMolybdenumRutheniumRhodiumSilverPalladiumCadmiumIndiumTinAntimo
48、nyIodineTelluriumCesiumBariumLanthanumCeriumNeodymiumHafniumTantalumTungstenRheniumOsmiumIridiumPlatinumGoldMercuryThalliumLeadBismuthThoriumUranium7Li9Be11B12C14N16O19F23Na26Mg27Al28Si31P32S35Cl39K42Ca45Sc48Ti51V52Cr55Mn56Fe59Co60Ni63Cu66Zn or68Zn69Ga or71Ga70Ge or73Ge75As77Se79Br85Rb89Y91Zr93Nb100
49、Mo101Ru103Rh107Ag106Pd or108Pd114Cd115In117Sn or119Sn121Sb127I125Te or130Te133Cs138Ba139La140Ce146Nd176Hf or178Hf181Ta184W187Re190Os or192Os191Ir194Pt or196Pt197Au201Hg or202Hg205Tl208Pb209Bi232Th238UF 1710 083control. The equipment is suitable for use if the analysis datagroup is within the 3-sigma control limits and shows nononrandom trends.10.4 Upper and lower control limits for SPC must be withinat least 20 % of the mean of previously determined values ofthe relative ion currents.11. Standardization11.1 The GDMS instrument should be standardized usin
