1、BSI Standards PublicationBS ISO 14606:2015Surface chemical analysis Sputter depth profiling Optimization using layeredsystems as reference materialsBS ISO 14606:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 14606:2015.It supersedes BS ISO 14606:2000 whic
2、h is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee CII/60, Surface chemical analysis.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a
3、contract. Users are responsible for its correctapplication. The British Standards Institution 2015.Published by BSI Standards Limited 2015ISBN 978 0 580 81552 2ICS 71.040.40Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the a
4、uthority of theStandards Policy and Strategy Committee on 31 December 2015.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 14606:2015 ISO 2015Surface chemical analysis Sputter depth profiling Optimization using layered systems as reference materialsAnalyse chimique d
5、es surfaces Profilage dpaisseur par bombardement Optimisation laide de systmes mono- ou multicouches comme matriaux de rfrenceINTERNATIONAL STANDARDISO14606Second edition2015-12-01Reference numberISO 14606:2015(E)BS ISO 14606:2015ISO 14606:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DO
6、CUMENT ISO 2015, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior writte
7、n permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 14606:2015IS
8、O 14606:2015(E)Foreword ivIntroduction v1 Scope . 12 Terms and definitions . 13 Symbols and abbreviated terms .24 Setting parameters for sputter depth profiling 24.1 General . 24.2 Auger electron spectroscopy 34.3 X-ray photoelectron spectroscopy . 44.4 Secondary ion mass spectrometry . 45 Depth res
9、olution at an ideally sharp interface in sputter depth profiles . 45.1 Measurement of depth resolution 45.2 Average sputtering rate 55.3 Depth resolution z .56 Procedures for optimization of parameter settings 66.1 Alignment of sputtered area with a smaller analysis area 66.1.1 General 66.1.2 AES .
10、76.1.3 XPS with a small probe (for example monochromator) 76.1.4 XPS with a large area source (for example without monochromator) . 76.1.5 SIMS 76.2 Optimization of parameter settings 8Annex A (informative) Factors influencing the depth resolution . 9Annex B (informative) Typical single-layered syst
11、ems as reference materials 11Annex C (informative) Typical multilayered systems used as reference materials 12Annex D (informative) Uses of multilayered systems 13Bibliography .14 ISO 2015 All rights reserved iiiContents PageBS ISO 14606:2015ISO 14606:2015(E)ForewordISO (the International Organizati
12、on for Standardization) is a worldwide federation of national 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 ha
13、s the right to be represented on that committee. International 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.The p
14、rocedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the edit
15、orial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent righ
16、ts identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an expla
17、nation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this docum
18、ent is ISO/TC 201, Surface chemical analysis, Subcommittee SC 4, Depth profiling.This second edition cancels and replaces the first edition (ISO 14606:2000), of which it constitutes a minor revision to update the content of Table C.1iv ISO 2015 All rights reservedBS ISO 14606:2015ISO 14606:2015(E)In
19、troductionReference materials are useful in optimizing the depth resolution of sputter profiling methods in materials such as silicon wafers, multilayered devices (for example AlGaAs double-hetero lasers, high electron mobility transistors) and alloy-galvanized steel for corrosion-resistant car bodi
20、es.The specific applications of this International Standard are as follows:a) Single-layered and multilayered systems on a substrate as reference materials are useful for the optimization of depth resolution as a function of instrument settings in Auger electron spectroscopy, X-ray photoelectron spe
21、ctroscopy and secondary ion mass spectrometry.b) These systems are useful for illustrating the effects of the evenness of the sputter crater, the inclination of the crater bottom, the sample drift, the drift of sputter conditions (for example ion beam current density) on depth resolution.c) These sy
22、stems are useful for illustrating the effects of sputter-induced surface roughening and sputter-induced atomic mixing on depth resolution.d) These systems are useful for the evaluation of instrument performance for instrument suppliers and users.e) This International Standard is timely and topical,
23、and can be used for a basis of future development of sputter depth profiling.A list of ISO Guides related to this International Standard is given in the Bibliography.12345 ISO 2015 All rights reserved vBS ISO 14606:2015BS ISO 14606:2015Surface chemical analysis Sputter depth profiling Optimization u
24、sing layered systems as reference materials1 ScopeThis International Standard gives guidance on the optimization of sputter-depth profiling parameters using appropriate single-layered and multilayered reference materials in order to achieve optimum depth resolution as a function of instrument settin
25、gs in Auger electron spectroscopy, X-ray photoelectron spectroscopy and secondary ion mass spectrometry.This International Standard is not intended to cover the use of special multilayered systems such as delta doped layers.2 Terms and definitionsFor the purposes of this document, the following term
26、s and definitions apply.NOTE The terms used in this International Standard follow basically ASTM E 673976. The definitions of the terms used are to be modified to conform to those being developed by ISO/TC 201/SC 1, Terminology.2.1analysis areatwo-dimensional region of a sample surface measured in t
27、he plane of that surface from which the full signal or a specified percentage of that signal is detected2.2angle of incidenceangle between the incident beam and the local or average surface normal2.3crater edge effectsignals from the crater edge which often originate from depths shallower than the c
28、entral region of the crater formed in depth profiling2.4depth resolutiondepth range over which a signal intensity increases or decreases by a specified amount when profiling an ideally sharp interface between two mediaNote 1 to entry: By convention, a measure of the depth resolution is often taken t
29、o be the distance over which the signal intensity changes from 16 % to 84 % of the full change between the respective plateau values of the two media.72.5gated areadefined area within a larger area from which the signal may be obtained2.6image depth profilethree-dimensional representation of the spa
30、tial distribution of a particular elemental or molecular species (as indicated by emitted secondary ions or electrons) as a function of depth or material removed by sputteringINTERNATIONAL STANDARD ISO 14606:2015(E) ISO 2015 All rights reserved 1BS ISO 14606:2015ISO 14606:2015(E)2.7plateau regionreg
31、ion in which the signal remains constant or without significant variation with sputtering time2.8signal intensitystrength of a signal at the spectrometer output or after some defined data processingNote 1 to entry: Examples of signal intensity are the height of the peak above the background or the p
32、eak-to-peak heights in AES or the peak areas in XPS.2.9sputter depth profilecompositional depth profile obtained when the surface composition is measured as material is removed by sputtering2.10sputtering ratequotient of amount of sample material removed as a result of particle bombardment by timeNo
33、te 1 to entry: The rate may be measured as a velocity, a mass per unit area per unit time, or some other measure of quantity per unit time.3 Symbols and abbreviated termsz depth resolutionI signal intensityzsputtering rateAES Auger electron spectroscopySEM scanning electron microscopySIMS secondary
34、ion mass spectrometryXPS X-ray photoelectron spectroscopy4 Setting parameters for sputter depth profiling4.1 GeneralFor the purposes of this International Standard, typical probing and sputtering parameters for sputter depth profiling in AES, XPS and SIMS are given in Table 1 and Table 2. These para
35、meters represent a range which covers many different types of instrumentation. Recommended conditions for a particular instrument may be available from the respective instrument manufacturers and optimized by experimentation on the laboratory instrument using the information included in this Interna
36、tional Standard.2 ISO 2015 All rights reservedBS ISO 14606:2015ISO 14606:2015(E)Table 1 Typical probing parameters for sputter depth profilingAES XPS SIMSProbing species Electrons Photons:Mg K, Al KPrimary ions: Cs+, O, O2+, Ga+Energy 1 keV to 25 keV 1,253 keV, 1,486 keV 0,1 keV to 25 keVCurrent or
37、power 1 nA to 103nA (Faraday cup) 1 W to 104W (Source power)1 nA to 104nA (Faraday cup)Angle of incidence 0 30 eV).NOTE “Information depth” is the maximum depth, normal to the surface, from which useful information is obtained. The information depth can be identified with the sample thickness from w
38、hich a specified percentage (e.g. 95 % or 99 %) of the detected signal originates. In addition, the information depth may be determined from a measured, calculated or estimated emission-depth distribution function for the signal of interest. ISO 2015 All rights reserved 9BS ISO 14606:2015ISO 14606:2
39、015(E)A.3.2 Angle of emissionMore grazing emission reduces the sampling depth in AES and XPS as cos and so improves the measured depth resolution, where is the attenuation length, is the angle between surface normal and optical axis of the analyser.NOTE Usually molecular ions such as dimers (i.e. A2
40、+) or trimers (i.e. A3+) used in SIMS secondary ion signals have nonlinear responses of intensity with concentration and so give artificially low values of depth resolution.A.4 Experimental considerationsA.4.1 The sputtering rate of some polycrystalline films has been shown to be nonlinear due to to
41、pography development when sputtering films are not rotated.39A.4.2 The sputtering rate may be affected in AES by electron irradiation during the sputtering process. The electron beam can be unfocused to avoid this effect which can double the sputtering rate (e.g. on SiO2thin films). Similar effects
42、have been reported in XPS where focused X-ray sources can affect sputtering yields.A.4.3 Ion irradiation produces Auger electrons at energies up to 100 eV. If the electron spectrum is acquired with the ion beam turned on, care should be taken to minimize the presence on the resulting spectrum.1011Mo
43、dulation techniques, such as beam brightness modulation, can minimize this effect by excluding Auger electrons present in the ion beam (giving a DC signal) from the phase-modulated Auger electrons present in the electron-beam blanking.A.4.4 The roughness of the surface being sputtered affects the de
44、pth resolution. For polycrystalline samples the surface roughness increases during ion sputtering. This can be minimized or eliminated by using multiple ion sources on the same instrument40and by rotating the sample under ion beam irradiation.2833353940A.4.5 The use of oxygen flooding of the sample
45、surface is sometimes used in SIMS analysis (with an oxygen primary ion beam) to reduce transient ion-yield effects on interfaces. The oxygen-flooding technique may also be used to reduce sputter-induced topography.A.4.6 Sample contamination should be a consideration when depth profiling because the
46、sample vacuum environment may have an influence on the depth resolution. Accidental contamination of the sample surface can be checked by measuring the residual gases in the vacuum chamber using a residual gas analyser.A.4.7 Another kind of check can be made for sample contamination with respect to
47、time for AES and XPS techniques. It involves measuring sample contamination on a reactive material surface, such as that from pure titanium. A contamination appearance profile (CAP) measurement is made whereby the sample is first ion-sputter-cleaned until there is no detectable carbon, oxygen, or ot
48、her surface contaminants. Next, a CAP measurement is made for the time it takes to detect a significant peak of oxygen, carbon or another element of interest. This procedure can be automated using a computer-controlled system whereby a depth profile is collected with the ion beam turned off or by ei
49、ther turning off the ion gun high voltage or by closing the sputtering gas supply. The resulting profile shows the contamination signal versus time relationship. It is noted that this technique is not applicable for SIMS.10 ISO 2015 All rights reservedBS ISO 14606:2015ISO 14606:2015(E)Annex B (informative) Typical single-layered systems as reference materialsCertified reference materials from national laboratories and those traceable to them are useful in optimizing the depth resoluti
