ASTM E2444-2011(2018) Standard Terminology Relating to Measurements Taken on Thin Reflecting Films.pdf

1、Designation: E2444 11 (Reapproved 2018)Standard Terminology Relating toMeasurements Taken on Thin, Reflecting Films1This standard is issued under the fixed designation E2444; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year

2、 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 standard consists of terms and definitions pertain-ing to measurements taken on thin, reflecting films, such

3、asfound in microelectromechanical systems (MEMS) materials.In particular, the terms are related to the standards in Section 2,which were generated by Committee E08 on Fatigue andFracture. Terminology E1823 Relating to Fatigue and FractureTesting is applicable to this standard.1.2 The terms are liste

4、d in alphabetical order.1.3 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organizat

5、ion TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E1823 Terminology Relating to Fatigue and Fracture TestingE2244 Test Method for In-Plane Length Measurements ofThin, Reflecting Films Using an Optical InterferometerE2245 Test Method for Residual Strain Measure

6、ments ofThin, Reflecting Films Using an Optical InterferometerE2246 Test Method for Strain Gradient Measurements ofThin, Reflecting Films Using an Optical Interferometer3. Terminology3.1 Terms and Their Definitions:2-D data tracea two-dimensional group of points that isextracted from a topographical

7、 3-D data set and that isparallel to the xz-oryz-plane of the interferometricmicroscope. E2244, E22453-D data seta three-dimensional group of points with atopographical z-value for each (x, y) pixel location within theinterferometric microscopes field of view. E2244, E2245,E2246anchorin a surface-mi

8、cromachining process, the portion ofthe test structure where a structural layer is intentionallyattached to its underlying layer. E2244, E2245, E2246anchor lipin a surface-micromachining process, the free-standing extension of the structural layer of interest aroundthe edges of the anchor to its und

9、erlying layer.DISCUSSIONIn some processes, the width of the anchor lip may bezero. E2244, E2245, E2246bulk micromachininga MEMS fabrication process wherethe substrate is removed at specified locations. E2244,E2245, E2246cantilevera test structure that consists of a freestandingbeam that is fixed at

10、one end. E2244, E2245, E2246fixed-fixed beam a test structure that consists of a freestand-ing beam that is fixed at both ends. E2244, E2245in-plane length (or deflection) measurement, L (or D)Lthe experimental determination of the straight-linedistance between two transitional edges in a MEMS devic

11、e.DISCUSSIONThis length (or deflection) measurement is made paral-lel to the underlying layer (or the xy-plane of the interferometricmicroscope). E2244, E2245, E2246interferometera non-contact optical instrument used toobtain topographical 3-D data sets.DISCUSSIONThe height of the sample is measured

12、 along the z-axisof the interferometer. The x-axis is typically aligned parallel orperpendicular to the transitional edges to be measured. E2244,E2245, E2246MEMSmicroelectromechanical systems. E2244, E2245,E2246microelectromechanical systems, MEMSin general, thisterm is used to describe micron-scale

13、 structures, sensors,actuators, and technologies used for their manufacture (suchas, silicon process technologies), or combinations thereof.E2244, E2245, E2246residual strain, rin a MEMS process, the amount ofdeformation (or displacement) per unit length constrained1This test method is under the jur

14、isdiction of ASTM Committee E08 on Fatigueand Fracture and is the direct responsibility of Subcommittee E08.02 on Standardsand Terminology.Current edition approved May 1, 2018. Published May 2018. Orginiallyapproved in 2005. Last previous edition approved in 2011 as E2444111. DOI:10.1520/E2444-11R18

15、.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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box

16、C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the

17、 World Trade Organization Technical Barriers to Trade (TBT) Committee.1within the structural layer of interest after fabrication yetbefore the constraint of the sacrificial layer (or substrate) isremoved (in whole or in part) E2245, E2246sacrificial layera single thickness of material that is inten-

18、tionally deposited (or added) then removed (in whole or inpart) during the micromachining process, to allow freestand-ing microstructures. E2244, E2245, E2246stictionadhesion between the portion of a structural layerthat is intended to be freestanding and its underlying layer.E2245, E2246(residual)

19、strain gradient, sgL1a through-thicknessvariation (of the residual strain) in the structural layer ofinterest before it is released.DISCUSSIONIf the variation through the thickness in the structurallayer is assumed to be linear, it is calculated to be the positivedifference in the residual strain be

20、tween the top and bottom of acantilever divided by its thickness. Directional information is assignedto the value of s. E2245, E2246structural layera single thickness of material present in thefinal MEMS device. E2244, E2245, E2246substratethe thick, starting material (often single crystalsilicon or

21、 glass) in a fabrication process that can be used tobuild MEMS devices. E2244, E2245, E2246support regionin a bulk-micromachining process, the areathat marks the end of the suspended structure. E2244,E2245, E2246surface micromachininga MEMS fabrication processwhere micron-scale components are formed

22、 on a substrateby the deposition (or addition) and removal (in whole or inpart) of structural and sacrificial layers. E2244, E2245,E2246test structurea component (such as, a fixed-fixed beam orcantilever) that is used to extract information (such as, theresidual strain or the strain gradient of a la

23、yer) about afabrication process. E2244, E2245, E2246transitional edgethe side of a MEMS structure that ischaracterized by a distinctive out-of-plane vertical displace-ment as seen in an interferometric 2-D data trace. E2244,E2245, E2246underlying layer the single thickness of material directlybeneat

24、h the material of interest.DISCUSSIONThis layer could be the substrate. E2244, E2245,E22464. Keywords4.1 cantilevers; definitions; fixed-fixed beams; interferom-etry; length measurements; microelectromechanical systems;MEMS; polysilicon; residual strain; stiction; strain gradient;terminology; test s

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