1、Designation:E2244111Standard Test Method forIn-Plane Length Measurements of Thin,Reflecting FilmsUsing an Optical Interferometer1This standard is issued under the fixed designation E2244;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revisio
2、n,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.1NOTEReference(1)was editorially revised in September 2013.1.Scope1.1 This test method covers a procedure for measuringi
3、n-plane lengths(including deflections)of patterned thin films.It applies only to films,such as found in microelectromechani-cal systems(MEMS)materials,which can be imaged using anoptical interferometer,also called an interferometric micro-scope.1.2 There are other ways to determine in-plane lengths.
4、Using the design dimensions typically provides more precisein-plane length values than using measurements taken with anoptical interferometric microscope.(Interferometric measure-ments are typically more precise than measurements taken withan optical microscope.)This test method is intended for usew
5、hen interferometric measurements are preferred over usingthe design dimensions(for example,when measuring in-planedeflections and when measuring lengths in an unproven fabri-cation process).1.3 This test method uses a non-contact optical interfero-metric microscope with the capability of obtaining t
6、opographi-cal 3-D data sets.It is performed in the laboratory.1.4 The maximum in-plane length measured is determinedby the maximum field of view of the interferometric micro-scope at the lowest magnification.The minimum deflectionmeasured is determined by the interferometric microscopespixel-to-pixe
7、l spacing at the highest magnification.1.5 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 limi
8、tations prior to use.2.Referenced Documents2.1 ASTM Standards:2E2245 Test Method for Residual Strain Measurements ofThin,Reflecting Films Using an Optical InterferometerE2246 Test Method for Strain Gradient Measurements ofThin,Reflecting Films Using an Optical InterferometerE2444 Terminology Relatin
9、g to Measurements Taken onThin,Reflecting FilmsE2530 Practice for Calibrating the Z-Magnification of anAtomic Force Microscope at Subnanometer DisplacementLevels Using Si(111)Monatomic Steps(Withdrawn2015)32.2 SEMI Standard:4MS2 Test Method for Step Height Measurements of ThinFilms3.Terminology3.1 D
10、efinitions:3.1.1 The following terms can be found in TerminologyE2444.3.1.2 2-D data trace,na two-dimensional group of pointsthat is extracted from a topographical 3-D data set and that isparallel to the xz-or yz-plane of the interferometric micro-scope.3.1.3 3-D data set,na three-dimensional group
11、of pointswith a topographical z-value for each(x,y)pixel locationwithin the interferometric microscopes field of view.3.1.4 anchor,nin a surface-micromachining process,theportion of the test structure where a structural layer is inten-tionally attached to its underlying layer.1This test method is un
12、der the jurisdiction of ASTM Committee E08 on Fatigueand Fracture and is the direct responsibility of Subcommittee E08.05 on CyclicDeformation and Fatigue Crack Formation.Current edition approved Nov.1,2011.Published December 2011.Originallyapproved in 2002.Last previous edition approved in 2005 as
13、E2244 05.2For 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
14、 referenced onwww.astm.org.4For referenced Semiconductor Equipment and Materials International(SEMI)standards,visit the SEMI website,www.semi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.5 anchor lip,nin a surface-micromachinin
15、g process,the freestanding extension of the structural layer of interestaround the edges of the anchor to its underlying layer.3.1.5.1 DiscussionIn some processes,the width of theanchor lip may be zero.3.1.6 bulk micromachining,adja MEMS fabrication pro-cess where the substrate is removed at specifi
16、ed locations.3.1.7 cantilever,na test structure that consists of a free-standing beam that is fixed at one end.3.1.8 fixed-fixed beam,na test structure that consists of afreestanding beam that is fixed at both ends.3.1.9 in-plane length(or deflection)measurement,ntheexperimental determination of the straight-line distance be-tween two transitional edges in a MEMS device.3.1.9.1 DiscussionThis length(or deflection)measure-ment is made parallel to the underlying layer(or the xy-planeof the interfe