IEC 62047-6 pdf download – Semiconductor devices – Micro-electromechanical devices – Part 6: Axial fatigue testing methods of thin film materials

IEC 62047-6 pdf download – Semiconductor devices – Micro-electromechanical devices – Part 6: Axial fatigue testing methods of thin film materials
1 scope
This International Standard specifies the method for axial tensile-tensile force fatigue testingof thin film materials with a length and width under 1 mm and a thickness in the rangebetween 0,1 um and 10 um under constant force range or constant displacement range.Thinfilms are used as main structural materials for MEMs and micromachines.
The main structural materials for MEMS,micromachines,etc., have special features,such astypical dimensions of a few microns,，material fabrication by deposition，and test piecefabrication by means of non-mechanical machining，including photolithography. ThisInternational Standard specifies the axial force fatigue testing methods for micro-sized smoothspecimens,which enables a guarantee of accuracy corresponding to the special features.Thetests are carried out at room temperatures, in air,with loading applied to the test piece alongthe longitudinal axis.
2Normative references
The following referenced documents are indispensable for the application of this document.For dated references,only the edition cited applies. For undated references, the latest editionof the referenced document (including any amendments) applies.
IEC 62047-2:2006,Semiconductor devices – Micro-electromechanical devices – Part 2rensile testing method of thin fiim materials
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
maximum forcemax
highest algebraic value of applied force in a cycle
NOTE Adapted from ASTM E 1823-05a[1]1.
3.2
minimum forcePmin
lowest algebraic value of applied force in a cycle
NOTE Adapted from ASTME 1823-05a[1].
3.3
mean forcePmean
algebraic average of the maximum and minimum forces in constant amplitude loading, or ofindividual cycles
NOTE Adapted from ASTME 1823-05a[1].
3.4
force rangeAP
algebraic difference between the maximum and minimum forces in constant amplitude loading
3.5
maximum stressmax
highest algebraic value of applied stress in a cycle
3.6
minimum stressmin
lowest algebraic value of applied force in a cycle
3.7
mean stressmean
algebraic average of the maximum and minimum stress in constant amplitude loading, or ofindividual cycles
3.8
stress rangeAa
algebraic difference between the maximum and minimum stresses in constant amplitudeloading
3.9
maximum displacementmax
highest algebraic value of applied displacement in a cycle
3.10
minimum displacementmin
lowest algebraic value of applied displacement in a cycle
3.11
mean displacementmean
algebraic average of the maximum and minimum displacement in constant amplitude loading,or of individual cycles
3.12
displacement range8
algebraic difference between the maximum and minimum displacements in constant amplitudeloading
3.13
force ratiostress ratioR
algebraic ratio of the minimum force (or the minimum stress) to the maximum force (or themaximum stress)
4 Test piece
4.1 Design of test piece In order to minimize the influence of size, the test piece should have dimensions of the same order as that of the objective device component. The shape and dimensions of the specimen should be based on Annex C of IEC 62047-2. The dimensions of the plane shape of the specimen shall be within an accuracy range of ± 1 % as specified in IEC 62047-2. The length of the parallel part of the test piece shall be more than 2,5 times the width. See C.1 in IEC 62047-2. The curved part between the gripped ends and the parallel part should have a radius of curvature sufficient to not cause a fracture at the curved part due to stress concentration. See C.2 in IEC 62047-2. The gauge marks specified in IEC 62047-2 are not necessary if the marks may concentrate stress or initiate fatigue fractures.
4.2 Preparation of test piece The test piece should be fabricated using a process as similar as possible to that of the device to which the thin film is to be applied. The test piece also should be fabricated following the procedures specified in IEC 62047-2. The substrate removal process should be carefully chosen to prevent damaging the test piece. See C.3 in IEC 62047-2. The number of test pieces should be determined adequately according to the thin films tested. See Annex E.
4.3 Test piece thickness The thickness of each test piece shall be measured, as the film thickness is not usually uniform over a wafer. The accuracy of the measurement shall be within 5 %. Each test piece should be measured directly. However, the film thickness at the step height of a window opening etched near the test piece can be used as the thickness of a specimen in order to avoid mechanical damage from the use of a stylus profiler, etc. Methods of measuring film thickness and measurement errors are given in C.4 of IEC 62047-2.