1、Designation: F 2405 04Standard Test Method forTrace Metallic Impurities in High Purity Copper by High-Mass-Resolution Glow Discharge Mass Spectrometer1This standard is issued under the fixed designation F 2405; the number immediately following the designation indicates the year oforiginal adoption o
2、r, 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 concentrations of tracemetallic impurities in hig
3、h purity (99.95 wt. % pure, or purer,with respect to metallic trace impurities) electronic gradecopper.1.2 This test method pertains to analysis by magnetic-sectorglow discharge mass spectrometer (GDMS).1.3 This test method does not include all the informationneeded to complete GDMS analyses. Sophis
4、ticated computer-controlled laboratory equipment, skillfully used by an experi-enced operator, is required to achieve the required sensitivity.This test method does cover the particular factors (for example,specimen preparation, setting of relative sensitivity factors,determination of detection limi
5、ts, and the like) known by theresponsible technical committee to effect the reliability of highpurity copper analyses.1.4 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-pria
6、te safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E 135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related MaterialsE 173 Practice for Conducting Interlaboratory Studies ofMethods f
7、or Chemical Analysis of Metals3E 180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty ChemicalsE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE 876 Practice for Use of Statistics in the Evalu
8、ation ofSpectrometric DataF 1593 Test Method for Trace Metallic Impurities in Elec-tronic Grade Aluminum by High Mass-Resolution Glow-Discharge Mass Spectrometer3. Terminology3.1 Terminology in this test method is consistent withTerminology E 135. Required terminology specific to this testmethod, no
9、t covered in Terminology E 135, is indicated in 3.2.3.2 Definitions:3.2.1 campaigna test procedure to determine the accuracyof the instrument, which was normally performed at thebeginning of the day or after the instrument modification, orboth.3.2.2 reference samplematerial accepted as suitable foru
10、se as a calibration/sensitivity reference standard by all partiesconcerned with the analyses.3.2.3 specimena suitably sized piece cut from a referenceor test sample, prepared for installation in the GDMS ionsource, and analyzed.3.2.4 test samplematerial (copper) to be analyzed fortrace metallic impu
11、rities by this GDMS method.3.2.4.1 DiscussionGenerally the test sample is extractedfrom a larger batch (lot, casting) of product and is intended tobe representative of the batch.4. Summary of Test Method4.1 A specimen is mounted in a plasma discharge cell.Atoms subsequently sputtered from the specim
12、en surface areionized, and then focused as an ion beam through a double-focusing magnetic-sector mass separation apparatus. The massspectrum (the ion current) is collected as magnetic field oracceleration voltage, or both, and is scanned.4.2 The ion current of an isotope at mass Miis the totalmeasur
13、ed current, less contributions from all other interferingsources. Portions of the measured current may originate fromthe ion detector alone (detector noise). Portions may be due toincompletely mass resolved ions of an isotope or molecule with1This test method is under the jurisdiction of ASTM Commit
14、tee F01 onElectronics and is the direct responsibility of Subcommittee F01.17 on SputterMetallization.Current edition approved May 1, 2004. Published June 2004.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of
15、 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.mass close to, but not identical with Mi. In all such instancesthe interfer
16、ing contributions must be estimated 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 o
17、f the detectionlimit for the 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 re
18、ference material performed under 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 approp
19、riate isotopicabundance factors (A (Xi),A(Yj) and RSFs. I(Xi) and I(Yj)refer to the measured ion current from isotopes Xiand Yj,respectively, of atomic species X and Y as follows:X!Y!5RSFX/M!RSFY/M!3AYj!AXi!3IXi!IYj!where (X)/(Y) is the concentration ratio of atomic species Xto species Y. If species
20、 Y is taken to be the copper matrix (RSF(M/M) = 1.0), (X) is (with only very small error for pure metalmatrices) 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 ex
21、ample, sputtering 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 ana
22、lystsin various laboratories for unifying the protocol and parametersfor determining trace impurities in copper. The objective is toimprove laboratory-to-laboratory agreement of analysis data.This test method is also directed to the users of GDMSanalyses as an aid to understanding the determination
23、method,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 wt. ppm. With specialprecautions, detection limits to sub-ppb levels are possible.5.4 This test method may be used as a referee method forp
24、roducers and users of electronic-grade copper materials.6. Apparatus6.1 Glow Discharge Mass Spectrometer, with mass resolu-tion greater than 3500, and associated equipment and supplies.6.2 Machining Apparatus, capable of preparing specimensand reference samples in the desired geometry and with smoot
25、hsurfaces.7. Reagents and Materials7.1 ReagentsReagent and high purity grade reagents asrequired (MeOH, HNO3, and HF).7.2 Demineralized Water.7.3 Tantalum Reference Sample.7.4 Copper Reference Sample:7.4.1 To the extent available, copper reference materialsshall be used to produce the GDMS relative
26、sensitivity factorsfor the various elements being determined (see Table 1).7.4.1.1 As necessary, non-copper reference materials maybe used to produce the GDMS relative sensitivity factors forthe various elements being determined.7.4.2 Reference materials should be homogeneous (see11.1) and free of c
27、racks or porosity.7.4.3 At least two reference materials are required to estab-lish the relative sensitivity factors, including a 99.9999 % purecopper metal to establish the background contribution inanalyses.7.4.4 The concentration of each analyte for relative sensi-tivity factor determination shou
28、ld be at a factor of 100 greaterthan the detection limit determined using a 99.9999 % purecopper specimen, but less than 100 ppmw.7.4.5 To meet expected analysis precision, it is necessarythat specimens of reference and test material present the samesize and configuration (shape and exposed length)
29、in the glowdischarge ion source, with a tolerance of 0.2 mm in diameterand 0.5 mm in the distance of sample to cell ion 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
30、 must be cleanedby etching immediately prior to mounting the specimen andinserting it into the glow discharge ion source.8.2.1 In order to obtain a representative bulk composition ina reasonable analytical time, surface cleaning must remove allcontaminants without altering the composition of the spe
31、cimensurface.8.2.2 To minimize the possibility of contamination, cleaneach specimen separately, immediately prior to mounting in theglow discharge ion source.TABLE 1 Suite of Impurity Elements to Be AnalyzedANOTEEstablish RSFs for the following suite of elements:Aluminum Antimony Arsenic Beryllium B
32、ismuth Boron Calcium CarbonChromium Cobalt Germanium Gold Iron Lead Lithium MagnesiumManganese Molybdenum Nickel Niobium Nitrogen Oxygen Phosphorous PotassiumSelenium Silicon Silver Sodium Sulfur Tellurium Thorium TinTitanium Uranium Vanadium Zinc ZirconiumAAdditional species may be determined and r
33、eported, as agreed upon between all parties concerned with the analyses.F24050428.2.3 Prepare etching solutions in a clean container in-soluble in the contained solution.8.2.3.1 EtchingPerform etching by immersing the speci-men in a suitable acid mixture solution (4:1:1 H2O:HF:HNO3and 1:1 H2O:HNO3we
34、re found applicable). Etch the specimenuntil smooth, clean metal is exposed over the entire surface.8.3 Immediately after cleaning, wash the specimen withseveral rinses of high purity methanol, or other high purityreagent able to remove water from the specimen surface, anddry the specimen in the lab
35、oratory environment.8.4 Immediately mount and insert the specimen into theglow discharge ion source, minimizing exposure of thecleaned, rinsed and dried specimen surface to the laboratoryenvironment.8.4.1 As necessary, use a noncontacting gage when mount-ing specimens in the analysis cell specimen h
36、older to ensurethe proper sample configuration in the glow discharge cell (see7.4.5).8.5 Sputter etch the specimen surface in the glow dischargeplasma for a period of time before data acquisition to ensurethe cleanness of the surface (see 12.3). Pre-analysis sputteringconditions are limited by the n
37、eed to maintain sample integrity.Pre-analysis sputtering at twice the power used for analysisshould be adequate for sputter etch cleaning.9. Preparation of the GDMS Apparatus9.1 See Test Method F 1593, Section 9 on Preparation of theGDMS Apparatus.10. Instrument Quality Control10.1 See Test Method F
38、 1593, Section 10 on InstrumentQuality Control, using a copper reference standard in place ofan aluminum standard.11. Standardization11.1 The GDMS instrument should be standardized usinginternational recognized reference materials, preferably cop-per, to the extent such reference samples are availab
39、le.11.1.1 RSF values should, in the best case, be determinedfrom the ion beam ratio measurements of four randomlyselected specimens from each standard required, with fourindependent measurements of each pin.11.1.2 RSF values must be determined for the suite ofimpurity elements for which specimens ar
40、e to be analyzed (seeTable 1) using selected isotopes for measurement and RSFcalculation (see Table 2).12. Analysis Procedure12.1 Establish a suitable data acquisition protocol (DAP)appropriate for the GDMS instrument used for the analysis.12.1.1 The protocol must include, but is not limited to, the
41、measurement of elements tabulated in Table 1 and isotopestabulated in Table 2. Annex A1 lists significant spectralinterference in this testing.12.1.2 Instrumental parameters selected for isotope mea-surements must be appropriate for the analysis requirements:(1) ion current integration times to achi
42、eve desired precisionand detection limits; and (2) mass ranges about the analytemass peak over which measurements are acquired to clarifymass interference.12.2 Insert the prepared specimen into the GDMS ionsource, allow the specimen to cool to source temperature, andinitiate the glow discharge at pr
43、e-analysis sputtering condi-tions.12.3 After at least 5 min of pre-analysis sputtering, adjustthe glow discharge ion source sputtering conditions to theconditions required for analysis, ensuring that the gas pressurerequired to do so is within normal range.12.4 Analyze the specimen using the DAP pro
44、tocol, andaccept as final the concentration values determined only asdetection limits.TABLE 2 Isotope SelectionANOTEUse the following isotopes for establishing RSF values and forperforming analyses on test specimens.Element IsotopeAluminum Al 27Antimony Sb 121Arsenic As 75Beryllium Be 9Bismuth Bi 20
45、9Boron B 11Calcium Ca 44Carbon C 12Chromium Cr 52Cobalt Co 59Germanium Ge 70Gold Au 197Iron Fe 56Lead Pb 208Lithium Li 7Magnesium Mg 24Manganese Mn 55Molybdenum Mo 98Nickel Ni 58Niobium Nb 93Nitrogen N 14Oxygen O 16Phosphorous P 31Potassium K 39Selenium Se 82Silicon Si 28Silver Ag 109Sodium Na 23Sul
46、fur S 32Tellurium Te 125Thorium Th 232Tin Sn 124Titanium Ti 48Uranium U 238Vanadium V 51Zinc Zn 68Zirconium Zr 90AThis selection of isotopes minimizes significant interference. Additional spe-cies may be determined and reported, as agreed upon between all partiesconcerned with the analyses.TABLE 3 R
47、equired Relative Standard Deviation (RSD) for RSFDeterminations, Pre-Sputtering Period, and Plasma StabilityTests (between the last two measurements)Analyte ContentRangeConcentrationDifference, %Major (100 ppm) 5Minor (100 ppm 3 1 ppm) 10Trace (1 ppm 3 100 ppb) 20F240504312.5 Generate a MDAP (Modifi
48、ed Data Acquisition Proto-col) including only the elements determined to be present in thesample (from results of 12.4).12.6 Measure the sample at least two additional times (withat least 10-min intervals between the measurements) using theMDAP protocol until the criteria of 12.6.1 are met.12.6.1 If
49、 the concentration differences between the last twomeasurements are less than 5, 10 or 20 %, depending onconcentration (Table 3), the measurements are confirmed andthe last two measurements are averaged.12.6.2 If the concentration differences between the last twomeasurements are greater than 5, 10 or 20 %, depending onconcentration (Table 3), the sample is measured again with atleast 10 minutes between measurements. The measurementsare repeated until the concentration differences between the lasttwo measurements are less than 5, 10 or 20 %, depending onconcentration
