1、Designation: E1577 11Standard Guide forReporting of Ion Beam Parameters Used in SurfaceAnalysis1This standard is issued under the fixed designation E1577; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、 number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers the information needed to character-ize ion beams used in surface analysis.1.2 This guide does not cover all informa
3、tion required toperform a sputter depth profile (see referenced documents),specify any properties of the specimen except its surfacenormal, and discuss the rationale for choosing a particular setof ion beam parameters (1, 2).2This guide does assume that theion flux has a unique direction, that is, i
4、s an ion beam, ratherthan a wide spectrum of velocity vectors more typical of aplasma.1.3 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-priate safety and health practices a
5、nd determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3E673 Terminology Relating to Surface AnalysisE684 Practice for Approximate Determination of CurrentDensity of Large-Diameter Ion Beams for Sputter DepthProfiling of Solid Surfaces3. Term
6、inology3.1 Definitions:3.1.1 For definitions of terms used in this guide, seeTerminology E673.4. Summary of Guide4.1 This guide describes ion beam parameters to be reportedso that experiments can be reproduced and understood.5. Significance and Use5.1 Ion beams are utilized in surface analysis in tw
7、o ways.First, they can generate signals from the specimen, for ex-ample, in SIMS and ISS. Second, they can remove materialfrom the specimen surface while a surface analytical techniquedetermines the composition of the freshly exposed surface.This process is called sputter depth profiling. Ideally, t
8、his guiderequires reporting all characteristics of the ion beam that canpossibly affect the results so that the measurement can bereproduced.6. Information to be Reported6.1 Ion Gun InstrumentationSpecify the manufacturer,type, and model of the ion gun (as well as of the analyticalspectrometer). Rep
9、ort the base pressure of the spectrometervacuum chamber, the pressure in the vacuum chamber duringthe ion gun operation, and any information on the gas pressurewithin the ionization chamber of the ion gun. If a mass filter isused, note its characteristics.6.2 Recommended Ion Beam Parameters The foll
10、owingion beam parameters may vary in both space and time. Reportsuch variations. For example the ion beam may be pulsed as issometimes done in static SIMS. If so, report the pulse durationand repetition rate (Hz). The spatial uniformity of the ion beamcan be monitored by measuring the ion current wi
11、th a Faradaycup whose aperture diameter is much smaller in size than theion beam diameter (3). If a Faraday cup is used whose apertureis larger than the ion beam diameter, temporal variations of theion beam current can be observed.6.2.1 CompositionReport species present and their chargestates, for e
12、xample, Ar+and Ar+, as well as their relativeconcentrations. If a neutral trap is used, report its use and itslocation.6.2.2 Kinetic Energy (keV)Report the kinetic energy ofthe ion beam as it impacts on the specimen surface. It is thisenergy that controls many ion/solid effects (1) rather than theen
13、ergy of the ion beam as it leaves the gun. These two energieswill differ if the specimen is electrically biased.6.2.3 Ion Current (A)Report the method used to measurethe ion beam current. If a Faraday cup is used, note its aperturediameter relative to the ion beam diameter.1This guide is under the j
14、urisdiction of ASTM Committee E42 on SurfaceAnalysis and is the direct responsibility of Subcommittee E42.08 on Ion BeamSputtering.Current edition approved May 1, 2011. Published June 2011. Originallyapproved in 1993. Last previous edition approved in 2004 as E1577 04. DOI:10.1520/E1577-11.2The bold
15、face numbers given in parentheses refer to a list of references at theend of this guide.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summa
16、ry page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.2.4 Ion Current Density (A/m2)The ion beam currentdensity is the ion current passing through a unit cross-sectionalarea whose normal is parallel to the ion
17、beam direction. It canbe determined using a small aperture Faraday cup by measur-ing the total ion current collected by the Faraday cup dividedby the area of the Faraday cup aperture and by the cosine of theangle between the ion beam and the normal to the Faraday cupaperture. In this case, the Farad
18、ay cup aperture must be smallenough so that the current density may be assumed to beconstant over the whole Faraday cup aperture.6.2.4.1 Another method consists of measuring the ion beamcurrent of a rastered ion beam and dividing by the area of theraster. In this case, the raster deflections should
19、be much largerthan the ion beam size.6.2.4.2 Ion current density and ion beam size are furtherdiscussed in Practice E684.6.2.5 Ion Beam Size GaussianThe two sigma width of asymmetrical Gaussian ion beam may be measured from thedistance between 16 and 84 % intensity values as the ion beamis moved per
20、pendicularly across a sharp edge. The full width athalf maximum would be equivalent to 1.177 times this value.The axial symmetry may be checked by imaging details of atest sample.6.2.5.1 If the ion beam is rastered, report the rastered beamdimensions on the specimen.6.2.6 Total Dose (Ions/m2)Report
21、the total dose, definedas the total charge per unit area that impinges on the specimen,so that ion beam damage can be assessed or number of atomssputtered can be estimated.6.2.7 Angle of Incidence (Degrees)Report the angle ofincidence, that is, the angle between the specimen surfacenormal and the in
22、cident ion beam direction.6.2.8 Specimen RotationIf specimen rotation is used,specify rotation rate and any effect on ion beam angle (that is,rotation axis not the sample normal (4).6.3 Second Ion GunIf a second ion gun is used, forexample, to reduce surface roughness, also report its param-eters.6.
23、4 Alignment of Ion BeamReport the procedure for thealignment of the ion beam with the probing beam, for example,an electron beam in Auger electron spectroscopy, so they arecoincident on the specimen surface. Examples of this proce-dure are: use of a Faraday cup to alternately probe the positionof ea
24、ch beam; and adjustment of the ion gun deflectionvoltages or mechanical position until a visible sputter crater iscentered on the SEM image in a scanning Auger microprobe,or until the secondary electron images from both the scanningion beam and electron beam are coincident.6.5 Ion Beam Sputtering Ra
25、teThe ion beam sputteringrate can be reported relative to a reference material, such as athermal silicon dioxide thin film on silicon (5); the NiCrmultilayer NIST standard reference material SRM 21354(6);tantalum pentoxide thin film on tantalum5, the NPL certifiedreference material CRM261 (7); or th
26、e multilayer GaAs/AIAssuperlattice reference material available through the SurfaceAnalysis Society of Japan. The average ion beam sputteringrate on the specimen may be measured from the sputter craterdepth divided by sputter etch time. The sputter crater depth isascertained from a stylus profilomet
27、er measurement across thediameter of the sputter crater on the specimen.7. Keywords7.1 ion beam sputtering; surface analysisREFERENCES(1) Bevolo, A.J., “Ion-Solid Interactions in Surface Analysis,” Charac-terization of Semiconductor Materials, Principles, and Methods, Vol I,G. Mcguire, Ed., Noyes Pu
28、bl: New Jersey, 1989, pp. 147232.(2) Hoffman, S., Wagner, T., and Wang, J.Y. “Sputter Depth Profiling inAES and EPS,” Chapter 22, Surface Analysis by Auger and X-rayPhotoelectron Spectroscopy; Eds. Briggs, D., and Grant, J.T., IMPublications: Chichester, 2003.(3) For a discussion of appropriate Fara
29、day cup dimensions (aperture anddepth) and Faraday cup use, see Ingram, G.D. and Seah, M.P., “E:Scientific Instruments,” Journal of Physics, Vol 22, 1989, pp.242249.(4) Zalar, A., Thin Solid Films 124, 1989, p. 223.(5) Degreve, B., and Ged, P., Surface and Interface Analysis, Vol 5, 1983,p. 83.(6) F
30、ine, J., Navinsek, B., Davarya, F., and Andreadis, T.D., Journal ofVacuum Science Technology 20, 449, 1982; Hoffman, S., and Zalar,A.,Surface and Interface Analysis 10, 1987, p. 7.(7) Hunt, C.P., and Seah, M.P., Surface and Interface Analysis 5, 1983,pp. 199209; Seah, M.P., Holbourn, M.W., Davies, J
31、.A., and Ortega,C., Journal of Vacuum Science Technology, A5, 1987, p. 19881993.4Available from National Institute of Standards and Technology (NIST), 100Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.5Available from National Physical Laboratory, Hampton Road, Teddington,Midd
32、lesex TW11 0LW, England, http:/www.npl.co.uk.E1577 112ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent r
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35、ng you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).E1577 113
