1、Designation: F 1710 97 (Reapproved 2002)Standard 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 ye
2、ar 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of concentr
3、a-tions of trace metallic 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 co
4、nstituent, for example, 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
5、the required sensitivity.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.
6、5 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 Doc
7、uments2.1 ASTM Standards:E 135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related Materials2E 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 I
8、ndustrial Chemicals4E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method5E 1257 Guide for Evaluating Grinding Materials Used forSurface Preparation in Spectrochemical Analysis23. Terminology3.1 Terminology in this test method is consistent withTerminology
9、 E 135. 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, cle
10、aning of 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
11、 from a 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
12、is intended 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 separationa
13、pparatus. 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 origin
14、ate fromthe ion detector alone (detector noise). Portions may be due to1This test method is under the jurisdiction of ASTM Committee F01 onElectronics and is the direct responsibility of Subcommittee F01.17 on SputterMetallization.Current edition approved Dec. 10, 2002. Published May 2003. Originall
15、yapproved in 1996. Last previous edition approved in 1997 as F 1710 97.2Annual Book of ASTM Standards, Vol 03.05.3Discontinued. See 1996 Annual Book of ASTM Standards, Vol 03.05.4Annual Book of ASTM Standards, Vol 15.05.5Annual Book of ASTM Standards, Vol 14.02.1Copyright ASTM International, 100 Bar
16、r Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.incompletely mass resolved ions of an isotope or molecule withmass close to, but not identical with, Mi. In all such instancesthe interfering contributions must be estimated and subtractedfrom the measured signal.4.2.1 If t
17、he 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 current due to the isotope.4.3 The composition of the te
18、st 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 under the same analyticalconditions, source configuration,
19、 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 factors (A(Xi), A(Yj) and RSFs. I(Xi) and I(Yj) referto the me
20、asured 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 be the titanium matrix(RSF(M/M) = 1.0), (X) is (with on
21、ly 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, sputtering targets, evaporation sources) used inthin film meta
22、llization 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 various laboratories for unifying the protocol and parameters
23、for 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,and the significance and reliability of reported GDMS d
24、ata.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 forproducers and users of electronic-grade titanium materials.6.
25、Apparatus6.1 Glow Discharge Mass Spectrometer, with mass resolu-tion greater than 3500, and associated equipment and supplies.The GDMS must be fitted with a liquid nitrogencooledion-source specimen cell.6.2 Machining Apparatus, capable of preparing specimensand reference samples in the required geom
26、etry 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 Sample.7.4 Titanium Reference Sample.7.4.1 To the extent available, titanium reference materialsshall be used to produce th
27、e 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 sensitivity factors for thevarious elements being determined.7.4.3 Reference materials should be homogeneous and freeof
28、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 titanium metal to establishthe background contribution in analyses.7.4.5 The concentration of each analyte for relative sen
29、si-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 lessthan 100 ppmw.7.4.6 To meet expected analysis precision, it is necessarythat specimens of reference and test material pre
30、sent 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 ion exit slit.8. Preparation of Reference Standards and TestSpecimens8.1 The surface of the parent material must not be
31、 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 discharge ion source.8.2.1 In order to obtain a representative bulk composition ina reasonable analysis time, surface cleani
32、ng must remove allcontaminants without altering the composition of the specimensurface.8.2.2 To minimize the possibility of contamination, cleaneach specimen separately immediately prior to mounting in theglow discharge ion source.8.2.3 Prepare and use etching solutions in a clean containerinsoluble
33、 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 exposedover the entire surface.8.2.5 Immediately after cleaning, wash the specimen withhigh purity rinses and thoroughly
34、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 Immediately mount and insert the specimen into theglow discharge ion source, minimizing exposure of thecleaned, rinsed, specimen
35、 surface to the laboratory environ-ment.F 1710 97 (2002)28.3.1 As necessary, use a noncontacting gage when mount-ing specimens in the analysis cell specimen holder to ensurethe proper sample configuration in the glow discharge cell (see7.4.6).8.4 Sputter etch the specimen surface in the glow dischar
36、geplasma 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. If sputter cleaning and analysis are carried out underdifferent plasma conditions, accuracy should be establ
37、ished 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 106torr before operation.The background pressure in the mass analyzer should be lessthan 5 3 107torr during operati
38、on.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 instrument must be adjusted to the appro-priate mass peak shape and mass resolving power for therequired analysis.9.5
39、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 least weekly.9.5.1 If both Faraday cup collector for ion current measure-ment and ion counting detectors are use
40、d 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 specimen of tantalum, measure the ioncurrent from the major isotope (181Ta) using the ion currentFaraday cup detect
41、or, 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 should be 1 % or less.9.5.1.2 The ion counting efficiency is calculated by multi-plying the ratio of the180Ta i
42、on 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 ion currentmeasurements from the ion counting detector obtained inanalyses by dividing the ion current by the I
43、CE 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.10.2 A recommended procedure is the measurement of therelative ion currents of selected analytes and the matri
44、xelement 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 demonstrate that the analysis process is in statisticalTABLE 1 Suite of Impurity Elements to be Analyzed, withAppr
45、opriate Isotope SelectionNOTE 1Establish RSFs for the following suite of elements, using theindicated isotopes for establishing RSF values and for performinganalyses of test specimens.NOTE 2This selection of isotopes minimizes significant interferences(see Annex A1.). Additional species may be deter
46、mined and reported, asagreed upon by all parties concerned with the analyses. Other isotopes canbe selected to assist mass spectrum peak identification or for otherpurposes.LithiumBerylliumBoronCarbonNitrogenOxygenFluorineSodiumMagnesiumAluminumSiliconPhophorusSulfurChlorinePotassiumCalciumScandiumT
47、itaniumVanadiumChromiumManganeseIronCobaltNickelCopperZincGalliumGermaniumArsenicSeleniumBromineRubidiumYttriumZirconiumNiobiumMolybdenumRutheniumRhodiumSilverPalladiumCadmiumIndiumTinAntimonyIodineTelluriumCesiumBariumLanthanumCeriumNeodymiumHafniumTantalumTungstenRheniumOsmiumIridiumPlatinumGoldMe
48、rcuryThalliumLeadBismuthThoriumUranium7Li9Be11B12C14N16O19F23Na26Mg27Al28Si31P32S35Cl39K42Ca45Sc48Ti51V52Cr55Mn56Fe59Co60Ni63Cu66Zn or68Zn69Ga or71Ga70Ge or73Ge75As77Se79Br85Rb89Y91Zr93Nb100Mo101Ru103Rh107Ag106Pd or108Pd114Cd115In117Sn or119Sn121Sb127I125Te or130Te133Cs138Ba139La140Ce146Nd176Hf or17
49、8Hf181Ta184W187Re190Os or192Os191Ir194Pt or196Pt197Au201Hg or202Hg205Tl208Pb209Bi232Th238UF 1710 97 (2002)3control. 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 usingNIST traceable reference materials, preferably titanium, to theextent such reference samples are available.
