ASTM_E_1813_-_96_2007.pdf

Designation:E181396(Reapproved 2007)Standard Practice forMeasuring and Reporting Probe Tip Shape in ScanningProbe Microscopy1This standard is issued under the fixed designation E1813;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.INTRODUCTIONAn image produced by a stylus scanning in close proximity to a surface is usually not an exactreplica of the surface.The data are subject to a type of distortion called dilation.The amount ofdilation depends on the shape and the orientation of the probe as well as the surface topography(1).2Analysis of the scanned probe images thus requires knowledge of the probe shape and orientation.1.Scope1.1 This practice covers scanning probe microscopy anddescribes the parameters needed for probe shape and orienta-tion.1.2 This practice also describes a method for measuring theshape and size of a probe tip to be used in scanning probemicroscopy.The method employs special sample shapes,known as probe characterizers,which can be scanned with aprobe microscope to determine the dimensions of the probe.Mathematical techniques to extract the probe shape from thescans of the characterizers have been published(2-5).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:3F1438 Test Method for Determination of Surface Roughnessby Scanning Tunneling Microscopy for Gas DistributionSystem Components3.Terminology3.1 Definitions:3.1.1 active lengthlength of the region of the probe tip thatcould come into contact with the sample during a scan,and isset by the height of the tallest feature encountered,and itshould be less than the probe length(see Fig.1).3.1.2 characterized lengththe region of the probe whoseshape has been measured with a probe characterizer(see Fig.1).3.1.3 concave probea probe that is not convex.3.1.4 convex probethe probe is convex if for any twopoints in the probe,the straight line between the points lies inthe probe.3.1.4.1 DiscussionConical and cylindrical probes areconvex,while flared probes are not.Minor imperfections in theprobe,caused for instance by roughness of the probe surface,should not be considered in determining whether a probe isconvex.3.1.5 dilationthe dilation of a set A by a set B is defined asfollows:A1B 5 A1b!(1)bBThe image I produced by a probe tip T scanning a surfaceS is I=S+(T)(6).This is the surface obtained if an in-verted image of the tip is placed at all points on the surface.The envelope produced by these inverted tip images is theimage of the surface(3).3.1.6 erosionthe erosion of a set A by a set B is defined asfollows:A 2 B 5 A 2 b!.(2)bBAn upper bound for the surface S is I (T),where I isthe image and T is an inverted image of the probe tip(5).1This practice is under the jurisdiction of ASTM Committee E42 on SurfaceAnalysis and is the direct responsibility of Subcommittee E42.14 on STM/AFM.Current edition approved June 1,2007.Published June 2007.Originallyapproved in 1996.Last previous edition approved in 2002 as E1813 96(2002).DOI:10.1520/E1813-96R07.2The boldface numbers in parentheses refer to the list of references at the end ofthis document.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 Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.7 feedback-induced distortiondistortion of a scantrace arising from the inability of the probe microscopefeedback to maintain close proximity between the tip andsurface,which can be caused by scanning too quickly andchanges with scan speed and scan direction.3.1.8 flexing-induced distortiondistortion of a scan tracearising from flexing of the probe or shank during scanning.3.1.9 probe apexend of the probe tip,which is farthestfrom the shank.3.1.9.1 DiscussionFor some shapes,the position of theapex is somewhat arbitrary.The apex position coincides withthe origin of the coordinate system used to describe the probe.3.1.10 probe characterizera structure designed to allowextraction of the probe tip shape from a scan of the character-izer.3.1.11 probe flankside of the probe in the region betweenthe apex and the shank.3.1.12 probe length Ltdistance between the apex and theshank(see Fig.1).3.1.13 probe shankstiff structure supporting the probe tip.3.1.14 probe stiffnessresistance of the probe from flexingcaused by lateral forces,expressed as a force constant(N/m)des