ASTM_E_1634_-_11.pdf

Designation:E163411Standard Guide forPerforming Sputter Crater Depth Measurements1This standard is issued under the fixed designation E1634;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A 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 preferred procedure for acquiringand post-processing of sputter crater depth measurements.Thisguide is limited to stylus-type surface profilometers equippedwith a stage,stylus,associated scan and sensing electronics,video system for sample and scan alignment,and computerizedsystem.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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 and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E673 Terminology Relating to Surface Analysis(Withdrawn2012)33.Terminology3.1 Definitions:3.1.1 Terms used in surface analysis are defined in Termi-nology E673.4.Significance and Use4.1 Sputter crater depth measurements are performed inorder to determine a sputter rate(depth/time)for each matrixsputtered during a sputter depth profile or similar in-depth typeanalyses.From sputter rate values,a linear depth scale can becalculated and displayed for the sputter depth profile.4.2 Data obtained from surface profilometry are useful inmonitoring instrumental parameters(for example,raster size,shape,and any irregularities in topography of the sputteredcrater)used for depth profiles.5.General Procedure5.1 Upon completing a sputter depth profile,mark the craterfor future identification(one can mark the exterior corner(s)ofa crater with features,for example,lines,holes,etc.,producedusing an unrastered ion beam).Note the crater orientation withrespect to the other sample features5.2 Place the sample on the profilometer stage surface.If thesample has an area of less than 1 cm2,mount the sample ontoanother larger flat surface to prevent sample movement whenprofilometry is performed.The system should be reasonablyleveled;for details on instrumental adjustments,see manufac-turers operating manual(s).Keep the environment as dust-freeas possible and dust-off the sample surface with a clean air/gasjet before performing the measurement.5.3 Pre-select surface profilometer operational settings;computerized models are commonly used.Most surface profi-lometers commonly permit selection of the following param-eters:5.3.1 Stylus type(for example,diamond stylus).5.3.2 Stylus radius(for example,5 m;various stylus radiiareavailabledependingupondesiredresolutionofmeasurement,and to a certain degree the strength of the stylustip for varying hardness of materials).5.3.3 Stylus force(that is,force exerted on the analyticalsample during operation,for example,15 mg;this is animportant variable when profiling a sample with high hardnesslevels;damage to the stylus may occur,and hence damage tothe instrumentation or errors in profilometry measurements,orboth,may result),similarly,excessive force can damage softsamples such as polymers or photoresists and result in errone-ous measurements.5.3.4 Scan speed(for example,50 m/s;this value isdependent upon permissible noise levels,accuracy,etc.,and istypically determined experimentally).5.3.5 Scan length(one typically uses twice the crater size toallow for scanning over the level areas about the sputteredcrater.1This guide is under the jurisdiction of ASTM Committee E42 on SurfaceAnalysis and is the direct responsibility of Subcommittee E42.06 on SIMS.Current edition approved Nov.1,2011.Published November 2011.Originallyapproved in 2002.Last previous edition approved in 2007 as E1634 02(2007).DOI:10.1520/E1634-11.2For 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 Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.3.6 Number of scans for signal averaging(for example,three repetitive scans averaged to improve the signal-to-noiseratio).5.4 Lower the stylus in an area outside the sputtered crater,at a distance from the crater edge of approximately one-half theactual crater size,and in a reasonably smooth area to traversethe entire crater length.The scan path is typically chosen acrossthe center of the sputtered crater in one direction with arepetitive measurement in the perpendicular direction.6.Interpretation