1、 Reference number ISO/TR 16268:2009(E) ISO 2009TECHNICAL REPORT ISO/TR 16268 First edition 2009-10-01 Surface chemical analysis Proposed procedure for certifying the retained areic dose in a working reference material produced by ion implantation Analyse chimique des surfaces Mode opratoire propos p
2、our certifier la dose arique retenue dans un matriau de rfrence de travail produit par implantation dions ISO/TR 16268:2009(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless th
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7、rg Web www.iso.org Published in Switzerland ii ISO 2009 All rights reservedISO/TR 16268:2009(E) ISO 2009 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Normative references1 3 Terms and definitions .1 4 Symbols and abbreviated terms 5 5 Concept and procedure 6 5.1 General
8、 information 6 5.2 Preparation of the working and transfer reference materials.8 5.3 Measurement of retained areic dose in the transfer reference material8 5.4 Compatibility of the working reference material and the surface-analytical method 8 6 Requirements.9 6.1 Reference materials 9 6.2 Instrumen
9、tation requirements9 6.2.1 Ion implanter 9 6.2.2 Wavelength-dispersive X-ray fluorescence spectrometer9 6.2.3 Electron microprobe .10 6.3 Ion-implantation requirements.10 6.4 Uniformity requirement.10 7 Certification10 7.1 Working reference material against the transfer reference material .10 7.2 Tr
10、ansfer reference material against the secondary reference material.10 7.3 Retained areic dose of the working reference material.11 Annex A (informative) Ion implantation 12 Annex B (informative) Ion-implantation dosimetry13 Annex C (informative) X-ray fluorescence spectrometry14 Annex D (informative
11、) Non-certified secondary reference materials and substitutes.15 Annex E (informative) Uncertainties in measurements of areic dose .16 Bibliography19 ISO/TR 16268:2009(E) iv ISO 2009 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of nat
12、ional standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. Interna
13、tional organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the r
14、ules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by a
15、t least 75 % of the member bodies casting a vote. In exceptional circumstances, when a technical committee has collected data of a different kind from that which is normally published as an International Standard (“state of the art”, for example), it may decide by a simple majority vote of its parti
16、cipating members to publish a Technical Report. A Technical Report is entirely informative in nature and does not have to be reviewed until the data it provides are considered to be no longer valid or useful. Attention is drawn to the possibility that some of the elements of this document may be the
17、 subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO/TR 16268 was prepared by Technical Committee ISO/TC 201, Surface chemical analysis, Subcommittee SC 2, General procedures. ISO/TR 16268:2009(E) ISO 2009 All rights reserved vIntroduction T
18、his Technical Report brings together experience to provide a proposed procedure, untested as a full procedure, to address the general problem of how to obtain a certified working reference material (WoRM) for the quantitative surface chemical analysis of a given solid material available in wafer (di
19、sc) form. The WoRM discussed here is essentially an ion-implanted wafer, where the virgin wafer chosen or prepared by the analyst has been ion-implanted with, typically, one isotope of a chemical element (henceforth referred to as the analyte) of an atomic number larger than that of silicon. This Wo
20、RM is certified by the proposed procedure for the areic dose of the analyte retained. The retained areic dose of the ion-implanted analyte in the WoRM wafer is certified by comparative measurement against the retained areic dose of the same analyte in an ion-implanted silicon wafer having the status
21、 of a (preferably certified) secondary reference material (SeRM). The comparative measurement is performed in a two-step process in which an intermediary third reference material and two measurement techniques wavelength-dispersive X-ray fluorescence spectrometry (WD/XFS) and ion-implantation dosime
22、try are used. The intermediary reference material, referred to as a transfer reference material (TrRM), is also an ion-implanted silicon wafer and is a (non-identical) implantation twin of the WoRM (i.e. it is co-produced with the WoRM but differs in wafer type and retained areic dose). Its function
23、 is, firstly, to avoid possible secondary-excitation effects in a direct WD/XFS measurement on the WoRM and, secondly, to allow the WoRM to be certified also for retained areic dose levels far below the measuring range of WD/XFS. This certification of the WoRM is part of a new concept and procedure
24、for characterization of reference materials. In this concept, the WoRM, TrRM and SeRM have their places in a chain of reference materials and a sequence of certifications. The SeRM is at the interface between the area of responsibility of the analyst and that of a commercial supplier of reference ma
25、terials. This Technical Report describes the part of the procedure within the area of responsibility of the analyst and is based on the assumption that a suitable SeRM is obtainable. When an SeRM is available, the analyst must also have access to a suitable ion implanter and to a suitable wavelength
26、-dispersive X-ray fluorescence spectrometer for comparative measurement of retained areic doses. The wafer format requirement of the WoRMs implies a particular suitability for the analysis of semiconductor materials, although it is by no means restricted to this application. A restriction exists, ho
27、wever, in the choice of surface-analytical technique. Although specimen and WoRM may be identical in analyte and host matrix, the analyte may be present in a different chemical state and a different depth distribution. Meaningful results from referencing to the WoRM can then be obtained only if the
28、chosen surface-analytical technique is insensitive to the chemical state of the analyte and if the technique allows corrections for different depth distributions. This problem is addressed with special reference to analysis by secondary-ion mass spectrometry. With an appropriate choice of surface-an
29、alytical technique, the WoRMs can be used for quantitative measurement of homogeneous, ion-implanted, diffused and layered depth distributions of the analyte. This Technical Report is essentially based on Reference 1. This work has also been a project (Technical Working Area 2/Project 5) within the
30、international Versailles Project on Advanced Materials and Standards (VAMAS) 2 . TECHNICAL REPORT ISO/TR 16268:2009(E) ISO 2009 All rights reserved 1Surface chemical analysis Proposed procedure for certifying the retained areic dose in a working reference material produced by ion implantation 1 Scop
31、e This Technical Report specifies a procedure for the certification of the areic dose of an ion-implanted analyte element of atomic number larger than that of silicon retained in a working reference material (WoRM) intended for surface-analytical use. The WoRM is in the form of a polished (or simila
32、rly smooth-faced) wafer (also referred to as the host), of uniform composition and nominal diameter 50 mm or more, that has been ion- implanted with nominally one isotope of a chemical element (also referred to as the analyte), not already present in the host, to a nominal areic dose normally within
33、 the range 10 16atoms/cm 2to 10 13atoms/cm 2(i.e. the range of primary interest in semiconductor technology). The areic dose of the ion-implanted analyte retained in the WoRM wafer is certified against the areic dose of the same analyte retained in an ion- implanted silicon wafer having the status o
34、f a (preferably certified) secondary reference material (SeRM). Information is provided on the concept and the procedure for certification of the WoRM. There is also a description of the requirements for the reference materials, the comparative measurements and the actual certification. Supporting i
35、nformation on ion implantation, ion-implantation dosimetry, wavelength-dispersive X-ray fluorescence spectroscopy and non-certified substitutes for unobtainable SeRMs is provided in Annexes A to D. Sources and magnitudes of uncertainties arising in the certification process are detailed in Annex E.
36、2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 18115, Surface chemica
37、l analysis Vocabulary 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 18115 and the following apply. 3.1 certification of a reference material, by a procedure act of establishing the traceability of a property value to an accurate realization of the
38、unit in which the property value is expressed, where the certified value is accompanied by an uncertainty value at a stated level of confidence NOTE The term is used for both “the action of making certain” (i.e. certification by a procedure) and “the issuing of a certificate” stating what has been c
39、ertified by the procedure. ISO/TR 16268:2009(E) 2 ISO 2009 All rights reserved3.2 lower critical energy kinetic energy of an ion beam below which the backscattering of perpendicularly incident ions exceeds a specified percentage of the received areic dose 3.3 definitive method of referencing method
40、based on a valid, well-described theoretical foundation ensuring negligible systematic errors relative to end-user requirements, allowing a property to be measured either directly in terms of basic units of measurement or in terms closely related to the base units through physical or chemical theory
41、 expressed in exact mathematical equations NOTE A definitive method is a special method of reference (see ISO Guide 30 9 ) particularly suitable for the certification of primary reference materials by “allowing the property in question to be either measured directly in terms of basic units of measur
42、ement or in terms closely related to the base units”. An example thereof would be the vapour deposition of a high-purity element on a wafer and the measurement of the deposit by direct weighing. 3.4 areic dose dose density (deprecated) quotient of dN by dA, where dN is the number of particles of a s
43、pecified type from a mono-energetic, mass-analysed, quasi-parallel particle beam incident on a solid and suffering a specified fate on or after passing through a geometric surface area dA NOTE 1 The particles may be monoatomic or multiatomic. The chemical type, isotopic type and charge state of the
44、particles before incidence on the solid have to be specified. NOTE 2 The geometric surface area refers to the areal measure of the projection of the usually micro-rough surface onto an ideal plane parallel to that surface of the solid. NOTE 3 Areic dose is a generic term requiring further specificat
45、ion concerning the temporary or permanent fate of the particles before numeric values can be assigned. The fate of the particles refers to states of the particles prior to, during or after encounter with the solid, such as incidence on, transmission through, backscattering from, stopping within, re-
46、emission by sputtering from, or retention in the solid. 3.5 implanted areic dose D impquotient of dN impby dA, where dN impis the number of particles of a specified type from a mono-energetic, mass-analysed, quasi-parallel particle beam incident on a solid within a geometric surface area dA and capt
47、ured within the solid D imp= dN imp /dA NOTE 1 The particles may be monoatomic or multiatomic. The chemical type, isotopic type and charge state of the particles before incidence on the solid have to be specified. NOTE 2 The geometric surface area refers to the areal measure of the projection of the
48、 usually micro-rough surface onto an ideal plane parallel to that surface of the solid. NOTE 3 The implanted areic dose is smaller than the received areic dose if some of the particles incident on the solid are transmitted through or backscattered from the solid. 3.6 lower critical value of areic do
49、se for referencing one reference material with respect to another by means of wavelength-dispersive X-ray fluorescence spectrometry minimum value of the retained areic dose necessary for the repeatability of a specified measurement of this dose by this method to meet a given requirement ISO/TR 16268:2009(E) ISO 2009 All rights reserved 33.7 nominal areic dose D nomnominal (approximate and averaged) value of the received areic dose, obtained from the quotient of the particle equivalent of the beam current integral over tim
