Electron microscopy
 
Thickness Determination of TEM/STEM Samples
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Table 1227. Comparison of techniques of thickness determination of TEM/STEM samples.

Technique
Practical measurable thickness and limitation
Accuracy
Principle
100 - 500 nm, Crystalline only < 2 % Based on the variation of the intensity of the diffracted beam with thickness known as ‘Pendellösung’ fringes
Two beam diffraction
Crystalline only   Count the extinction fringes under two beam diffraction contrast conditions.
Crystalline only   Percentage of the intensity of diffracted spots at specific crystalline orientation
Crystalline only   Use the intensity of electron diffraction and Kikuchi lines
Crystalline only   Based on extinction distance
Crystalline and amorphous ~10 % Electron scattering, measuring the incident and transmitted intensities in the same image
Crystalline and amorphous ~ 15-20 % if no calibration is done The intensity ratio between the plasma peaks and the zero loss peak provides the thickness information
Crystalline and amorphous   Employ a known planar feature, such as a slip trace, precipitate, or stacking fault
Crystalline and amorphous   Focus the beam finely so that contamination points at the top and at the bottom are formed. And then, the sample tilted to measure the geometry

 

 

 

 

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