BS ISO 17109-2015 Surface chemical analysis Depth profiling Method for sputter rate determination in X-ray photoelectron spectroscopy Auger electron spectroscopy and secondary-ion s.pdf

1、BSI Standards PublicationBS ISO 17109:2015Surface chemical analysis Depth profiling Method forsputter rate determinationin X-ray photoelectronspectroscopy, Auger electronspectroscopy and secondary-ion mass spectrometry sputterdepth profiling using singleand multi-layer thin filmsBS ISO 17109:2015 BR

2、ITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 17109:2015.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 secreta

3、ry.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2015. Published by BSI StandardsLimited 2015ISBN 978 0 580 79589 3ICS 71.040.40Compliance with a British Standard cannot conf

4、er immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 August 2015.Amendments issued since publicationDate Text affectedBS ISO 17109:2015 ISO 2015Surface chemical analysis Depth profiling Method for sputter rate d

5、etermination in X-ray photoelectron spectroscopy, Auger electron spectroscopy and secondary-ion mass spectrometry sputter depth profiling using single and multi-layer thin filmsAnalyse chimique des surfaces Profilage dpaisseur Mthode pour la dtermination de la vitesse de pulvrisation lors du profila

6、ge dpaisseur par pulvrisation en spectroscopie de photolectrons par rayons X, spectroscopie dlectrons Auger et spectromtrie de masse des ions secondaires laide de films minces multicouchesINTERNATIONAL STANDARDISO17109First edition2015-08-01Reference numberISO 17109:2015(E)BS ISO 17109:2015ISO 17109

7、:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT 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

8、 posting on the internet or an intranet, without prior written 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 +

9、41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 17109:2015ISO 17109:2015(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Requirement of single- and multi-layer reference thin films 15 Determination of sputtering rate 2Annex A (informative) Report of intern

10、ational Round Robin Test 6Annex B (informative) Prediction of the rates for a wide range of other materials through tabulated values of sputtering yields .15Bibliography .16 ISO 2015 All rights reserved iiiContents PageBS ISO 17109:2015ISO 17109:2015(E)ForewordISO (the International Organization for

11、 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 has the

12、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 procedu

13、res 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 editorial

14、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 rights ide

15、ntified 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 explanation

16、 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 document is

17、 ISO/TC 201, Surface chemical analysis, Subcommittee SC 4, Depth profiling.iv ISO 2015 All rights reservedBS ISO 17109:2015ISO 17109:2015(E)IntroductionThe sputtering rate in surface chemical analysis is generally determined from the quotient of sputtered depth, measured using stylus profilometry, a

18、nd sputtering time. However, for multi-layered thin films, only the average sputtering rate is determined by this method. Therefore, this method is difficult to apply to multi-layered thin films comprised of materials with different sputtering rates. Sputtering rates are also affected by various exp

19、erimental parameters so that it is difficult for them to tabulate and to be used for sputter depth calibrations. For higher accuracies, it is important for sputtering rates to be determined under specific experimental conditions for each laboratory for sputter depth calibration. Sputter rates should

20、 be determined using single-layers that are much thicker than the projected range of the sputtering ions so that the surface transient effect is negligible or by using multi-layered thin films where the effect of surface transient phenomena can be excluded and interface transients can be minimized.

21、This International Standard is developed for the calibration of sputtered depth by determining the ion sputtering rate for depth profiling measurement with Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), and secondary ion mass spectrometry (SIMS) using single- and multi-la

22、yer thin films. The measured ion sputtering rate can be used for the prediction of ion sputtering rates for a wide range of other materials so that depth scales or sputtering times can be estimated in day-to-day samples through tabulated values of sputtering yields and bulk densities. ISO 2015 All r

23、ights reserved vBS ISO 17109:2015BS ISO 17109:2015Surface chemical analysis Depth profiling Method for sputter rate determination in X-ray photoelectron spectroscopy, Auger electron spectroscopy and secondary-ion mass spectrometry sputter depth profiling using single and multi-layer thin films1 Scop

24、eThis International Standard specifies a method for the calibration of the sputtered depth of a material from a measurement of its sputtering rate under set sputtering conditions using a single- or multi-layer reference sample with layers of the same material as that requiring depth calibration. The

25、 method has a typical accuracy in the range 5 % to 10 % for layers 20 nm to 200 nm thick when sputter depth profiled using AES, XPS, and SIMS. The sputtering rate is determined from the layer thickness and the sputtering time between relevant interfaces in the reference sample and this is used with

26、the sputtering time to give the thickness of the sample to be measured. The determined ion sputtering rate can be used for the prediction of ion sputtering rates for a wide range of other materials so that depth scales and sputtering times in those materials can be estimated through tabulated values

27、 of sputtering yields and atomic densities.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of th

28、e referenced document (including any amendments) applies.ISO 14606, Surface chemical analysis Sputter depth profiling Optimization using layered systems as reference materials3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1upper plateauregion ex

29、hibiting intensities higher than 95 % of the maximum intensity of the characteristic signal for that layer and covering more than half the thickness of that layer3.2lower plateauregion exhibiting intensities lower than the minimum intensity plus 5 % of the maximum intensity of the characteristic sig

30、nal for that layer and covering more than half the thickness of that layer4 Requirement of single- and multi-layer reference thin films4.1 The thickness of each layer in multi-layer thin films and the thickness of single-layer thin films shall be sufficiently thicker than the sum of the projected ra

31、nge of the sputtering ions and the information depth of the analytical method so that an upper plateau and a lower plateau shall be obtained for each layer in sputter depth profiling. The projected range can be simply calculated using SRIM code which is available from http:/www.srim.org.7INTERNATION

32、AL STANDARD ISO 17109:2015(E) ISO 2015 All rights reserved 1BS ISO 17109:2015ISO 17109:2015(E)NOTE Sample rotation during ion sputtering is shown to reduce surface roughness development especially of polycrystalline films11leading to sharper interfaces and a better estimate of sputtering rates.4.2 T

33、he surface and the interfaces shall be flat and parallel to each other to avoid any distortion of sputter depth profiles. The surface roughness is often measured using atomic force microscopy and the thickness variation using transmission electron microscopy. The surface roughness of sample and the

34、thickness variation of each layer shall be smaller than the sum of the projected range of the sputtering ions and the information depth of the analytical method.4.3 The thickness of each layer in multi-layer thin films and the thickness of single-layer thin films shall be determined by high resoluti

35、on cross-sectional transmission electron microscopy, grazing incidence X-ray reflectivity, medium energy ion scattering spectroscopy, or other appropriate methods for which an accurate uncertainty of measurement can be evaluated.4.4 The number of A/B layer pairs in the multi-layered reference thin f

36、ilms shall be greater than two since profiles of the first layer A and the last layer B shall not be used due to the surface and the final interface transient effects.4.5 For single-layer thin films, to minimize any likely contamination or surface oxidation problems, materials like gold on Si or SiO

37、2on Si and Ta2O5on Ta which are stable and remain clean or can easily be cleaned are recommended.5 Determination of sputtering rate5.1 Set the sputtering conditions to be those for which the sputtering rates are required. Changes in the sputtering species, the impact energy, and beam current will ch

38、ange the sputtering rates. The sputter depth profiling parameters are optimized according to ISO 14606.NOTE 1 A typical AES, XPS, and SIMS sputter depth profile is given in Figure A.2 to Figure A.4, respetively.NOTE 2 The ordinate axis units can be intensity, atomic fraction, an intensity ratio, con

39、centration, or whatever is the unit most linearly related to the amount of substance present at each depth.5.2 The sputter depth profiles shall be measured after the instrument has stabilized to minimize uncertainty due to instrumental fluctuation. Inspect the data, identify, and then ignore, in wha

40、t follows, any noise spikes.5.3 Measure the sputter depth profile of a single- or multi-layer reference thin film and determine the interface position by the point where the signal intensity of the element reaches 50 % of its value between the lower plateau where the element is essentially absent an

41、d the upper plateau level for the layer where it is present. The determination of the interface position by this procedure is applied to this International Standard until the development of an ISO Standard for interface position. The average intensity in the upper plateau region is the plateau inten

42、sity (Iupper). This shall be calculated by summing the intensity for each measurement where the intensity is greater than 95 % of the maximum intensity and dividing by the number of measurements used in the summation.A similar procedure shall be adopted for the determination of the lower plateau for

43、 each constituent of the profile (Ilower). The average intensity shall be calculated as follows:a) subtract the minimum intensity value in this part of the profile from all readings;b) calculate the value of 5 % of the maximum intensity (following the subtraction in one, above);c) sum all of the int

44、ensities which are less than the 5 % value calculated in two, above;d) divide the sum by the number of readings to get an average;2 ISO 2015 All rights reservedBS ISO 17109:2015ISO 17109:2015(E)e) add the minimum intensity to the average calculated in four to arrive at Ilower.The 50 % signal intensi

45、ty shall be calculated as follows: I50 %= (Iupper Ilower)/2.Examples of determining the upper plateau level and the lower plateau level are demonstrated in Figure A.2 to Figure A.4 for AES, XPS, and SIMS depth profiling, respectively. For single-layer thin films, the beginning of the sputter time is

46、 defined by the time where the intensity for the given element reaches 50 % of the upper plateau level in the similar manner.For some sputter depth profiling, often by SIMS, the interface positions may be significantly affected by changes in the matrix effect in the interface region. If the upper pl

47、ateau defined with intensities higher than 95 % of the maximum intensity is less than half of the layer thickness due to large distortions at interfaces, this standard shall not be used for sputter rate determination.NOTE 1 The 50 % of the plateau level is mentioned in ISO/TR 15969.2NOTE 2 A flow ch

48、art is given to guide the sputter rate determination of multi-layered thin films and single-layer thin films as below.5.4 The sputtering rates of layers of A, zA, and B, zB, are determined by dividing the thicknesses of layer A, dAR, and B, dBR, by the sputtering times of layers of A, tAR, and B, tB

49、R, of a reference A/B/A/B. multi-layer thin film. The unit of sputtering rate is nm/s.zdtAARAR=( )/ (1)zdtBBRBR=( )/ (2)The sputtering time of layers of A, tAR, is determined from the time interval from B/A to A/B interfaces and that of layers of B, tBR, is determined from the time period from A/B to B/A interfaces. Measure three sputter depth profiles to determine the uncertainties. If the standard deviation (SD) is inappropriate, the sputter depth profiling parameters shall be optimized according to ISO 14606 to improve