1、ICS 29.045 Supersedes October 1990 edition.Prfung von Materialien fr die Halbleitertechnologie Bestimmung von Elementspuren in Flssigkeiten Teil 2:Calcium (Ca), Cobalt (Co), Chrom (Cr), Kupfer (Cu), Eisen (Fe),Nickel (Ni) und Zink (Zn) in Flusssure mittelsPlasma-angeregter EmissionsspektrometrieIn k
2、eeping with current practice in standards published by the International Organization for Standardization(ISO), a comma has been used throughout as the decimal marker.Ref. No. DIN 50451-2 : 2003-04English price group 06 Sales No. 010601.05DEUTSCHE NORM April 2003 No part of this translation may be r
3、eproduced without the prior permission ofDIN Deutsches Institut fr Normung e.V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).Translation by DIN-Sprachendienst.In case of doubt, the German-language original should be consulted as
4、the authoritative text.Determination of trace elements in liquids for usein semiconductor technologyPart 2: Determination of calcium, chromium, cobalt, copper, iron, nickeland zinc in hydrofluoric acid by plasma emission spectrometryDocument comprises 4 pages.50451-2ForewordThis standard has been pr
5、epared by Technical Committee Prfung von Prozesschemikalien fr die Halb-leitertechnologie of the Normenausschuss Materialprfung (Materials Testing Standards Committee).AmendmentsThis standard differs from the October 1990 edition in that it has been revised in form and content.Previous editionDIN 50
6、451-2: 1990-10.1 ScopeThis standard specifies a method of determining traces in hydrofluoric acid of calcium, chromium, cobalt,copper, iron, nickel and zinc, in concentrations ranging from 1 ng/g to 1 000 ng/g, by means of plasmaemission spectrometry (inductively coupled (ICP) or direct current (DCP
7、). This method may also be used toanalyze other vaporizable liquids which have a percentage recovery between 75% and 125%.The presence of these metals is of relevance in the field of semiconductor technology.2 Normative referencesThis standard incorporates, by dated or undated reference, provisions
8、from other publications. Thesenormative references are cited at the appropriate places in the text, and the titles of the publications arelisted below. For dated references, subsequent amendments to or revisions of any of these publicationsapply to this standard only when incorporated in it by amend
9、ment or revision. For undated references, thelatest edition of the publication referred to applies.DIN 8120-1 Terminology associated with weighing machines Classification Scales and balancesDIN 32645 Establishing the decision limit, detection limit and determination limit under repeatabilityconditio
10、ns in chemical analysis Terminology, methods and evaluationDIN 38406-29 German standard methods for the examination of water, waste water and sludge Cations(group E) Determination of 61 elements by inductively coupled plasma mass spectrometry(E 29)Page 2DIN 50451-2 : 2003-04DIN 51008-2 Optical emiss
11、ion spectrometry (OES) Flame and plasma systemsDIN 51401-1 Atomic absorption spectrometry (AAS) TerminologySupplement 1to DIN 51401-1 Atomic absorption spectrometry (AAS) Terminology Explanatory notesDIN EN ISO 1042 Laboratory glassware One-mark volumetric flasks (ISO 1042 : 1998)DIN EN ISO 8655-2 P
12、iston-operated volumetric apparatus Part 2: Piston pipettes(ISO 8655-2 : 2002)DIN EN ISO 14644-1 Cleanrooms and associated controlled environments Part 1: Classification of air clean-liness (ISO 14644-1 : 1999)ISO 3696 : 1987 Water for analytical laboratory use Specification and test methodsASTM D 5
13、127-99 Standard guide for ultra pure water used in the electronics and semiconductor industry1 Boumans, P.W.J.M., Line coincidence tables for inductively coupled plasma atomic emission spectrometry,vol 1. 1980: Pergamon Press.3 Concept3.1 High-purity waterFor the purposes of this standard, high-puri
14、ty water is water which has been produced by demineralizationfollowed by filtration or double distillation and which contains no more than 0,05 ng/g of the elements to bedetermined, i.e. Ca, Co, Cr, Cu, Fe, Ni and Zn.NOTE: High-purity water as defined in ISO 3696 and ASTM D 5127-99, for example, doe
15、s not meet the require-ments of this standard.4 UnitThe concentration of trace elements is to be expressed in ng/g.5 PrincipleAfter evaporating the liquid under examination to dryness under dust-free conditions, the residue is taken upin a mixture of nitric acid, sulfuric acid and high-purity water
16、and analyzed by means of plasma emissionspectrometry. The ratio of the test portion mass to the relevant test solution mass after evaporation gives theenrichment factor.6 Reagents6.1 GeneralReagents shall not contain more than 0,5 ng/g of the elements to be determined. If the purity of commerciallya
17、vailable reagents is inadequate, they shall be purified (e.g. by subboiling distillation).6.2 65% to 70% (m/m) nitric acid, HNO3.6.3 96% (m/m) sulfuric acid, H2SO4.6.4 High-purity water, as in subclause 3.1.7 Apparatus and cleaning7.1 Apparatus7.1.1 Plasma emission spectrometer, (e.g. ICP or DCP spe
18、ctrometer), with automatic sampler (cf.DIN 51008-2).7.1.2 Vessels for evaporation and blank solution preparation, (e.g. beakers or dishes), cleaned, having avolume suitable for the test portion, and of a material as specified in DIN 38406-29, for example.7.1.3 Vessels for sample changer, of a contam
19、inant-free material as specified in DIN 38406-29, for example(preferably perfluoro alkoxyl alkane), and cleaned as in subclause 7.2, item b).7.1.4 Precision balance (cf. DIN 8120-1).7.1.5 Closable wide-neck containers, for gravimetrically prepared calibration solutions, of a material asspecified in
20、DIN 38406-29, for example, and cleaned as in subclause 7.2, item a).Page 3DIN 50451-2 : 2003-047.1.6 Volumetric flasks, for volumetrically prepared calibration solutions, of a material as specified inDIN 38406-29, for example, and cleaned as in subclause 7.2, item a).NOTE: See DIN EN ISO 1042 for ac
21、curacy classes of flasks.7.1.7 Piston-operated pipettes, of nominal capacities between 10 l and 1 000 l, as in DIN EN ISO 8655-2.Tips shall be cleaned as in subclause 7.2, item a).7.1.8 Equipment for evaporating liquids to dryness under dust-free and contaminant-free conditions, asspecified in DIN E
22、N ISO 14644-1, of at least ISO Class 5.7.2 CleaningVessels, flasks and pipette tips are to be cleaned either bya) leaving the apparatus to stand in a solution containing equal parts of nitric acid (as in subclause 6.2) andhigh-purity water for about 24 hours and then thoroughly rinsing with high-pur
23、ity water (the cleaning timefor pipette tips may be reduced to one hour), orb) evaporating nitric acid (as in subclause 6.2) in the apparatus for at least one hour and then rinsingthoroughly with high-purity water. This method may not be used for pipette tips.Other suitable cleaning methods may be u
24、sed.8 SamplingFrom each sample, at least three test portions (i.e. i 3) shall be taken for parallel determinations.The test portion mass, mP, shall be such that, after evaporation, the lowest measurable concentration of thetrace element under examination lies above the determination limit. This limi
25、t is to be determined as specifiedin DIN 32645 using a blank solution (cf. DIN 51401-1 and Supplement 1 to DIN 50541-1) as specified inclause 10 of the present standard. Each test portion (normally about 10 g to 200 g) is to be weighed into anevaporation vessel, with an uncertainty of measurement no
26、 greater than 5%.9 Sample pretreatment9.1 Evaporate a test portion in a vessel as in subclause 7.1.2 under dust-free conditions and avoiding anyuncontrolled loss of sample material.9.2 Heat the vessel to about 80 C and take up the residue first with 100 l to 500 l of nitric acid (dependingon the siz
27、e of the test portion and the interior diameter of the vessel), and then with 50 l to 250 l of sulfuricacid. Ensure that the entire vessel bottom is in contact with the acid mixture up to the time the residue has fullydissolved. Add 1 ml to 5 ml of high-purity water and mix by gently swirling. Deter
28、mine the mass, mML, of thesolution obtained (referred to below as the test solution) to an accuracy of 5% either by measuring the quantityof reagents and water added or by weighing. Using a piston-operated pipette, transfer the necessary quantityof test solution to the sample changer.10 Preparation
29、of blank solutionsTo establish the determination limit, prepare at least three blank solutions using the procedure specified inclause 9, but without transferring the solutions to the sample changer.11 Procedure11.1 MeasurementOptimize the spectrometer and measure the solutions at the optimum wavelen
30、gth recommended in 1 for theelements to be determined (see below). Carry out at least three measurements (i.e. n 3) with backgroundcorrection (cf. DIN 51008-2) for each test solution. Use these measured values to obtain the mean for eachelement in the test solution.NOTE: The following wavelengths ar
31、e recommended:lCa= 393,4 nmlCo= 238,9 nmlCr= 206,5 nmlCu= 324,7 nmlFe= 238,2 nmlNi= 231,6 nmlZn= 213,9 nmPage 4DIN 50451-2 : 2003-0411.2 CalibrationCalibrate the spectrometer using a standard method (cf. DIN 51401-1 and Supplement 1 to DIN 50541-1),taking an aqueous reference solution which contains
32、 all the elements to be determined and which has the samenitric acid and sulfuric acid concentrations as the test solution. Calibrations shall be carried out after thespectrometer has been adjusted and immediately prior to measurement.12 Calculation and expression of resultsThe enrichment factor, fi
33、, for each test portion shall be determined using equation (1):mPifi= (1)mMLiwith i = 1, 2, ., nwheremPiis the test portion mass, in g;mMLiis the test solution mass, in g.Calculate the arithmetic mean of the n values obtained for each element in the test solution, Ei. To convert theresults into conc
34、entrations for each element, divide the mean, Ei, by the relevant enrichment factor, fi.Calculate the mean of the blank values, L, in the same manner, using the average value of the enrichmentfactors.After subtracting L from Ei, take the total mean for each element to be determined, expressed as a c
35、ontent bymass (m/m), giving either the repeatability standard deviation, sr, or the median and the half-range, R/2.13 PrecisionInterlaboratory testing for Co, Cr, Cu, Fe and Ni yielded a reproducibility coefficient of variation between 10%and 30% for a concentration of 10 ng/g.Experience has shown t
36、hat a comparable precision of method can be assumed when analyzing other liquids.14 Test reportThe test report shall refer to this standard and include the following information:a) description of sample;b) type of spectrometer used and its parameters;c) mass of test portions (mPi) and of test soluti
37、ons (mMLi), and enrichment factors (fi);d) number of test portions (i);e) number of blank solutions (k);f) mean of blank values (L);g) total mean for each element (calculated as in clause 12), and the repeatability standard deviation, sr, orthe median and the half-range, all expressed in ng/g;h) any deviations from this standard;i) tester, test date and location.
