Mass thickness determination and microanalysis of thin films in the TEM—Revisited

Calibrating on a series of thicknesses of a single element we arrive at a simple method of mass thickness determination for amorphous and polycrystalline films in the transmission electron microscopy (TEM). The conditions to be fulfilled are: acceleration voltage 200 kV or higher and measuring the integrated transmitted electron intensity in a wide range of angles that contains also the Bragg reflections. Under these conditions the electron scattering depends on Z2 as predicted by the Rutherford approximation. There is no need to carry out a calibration for atomic number dependence. For multicomponent films of unknown composition the combination of electron and X-ray intensity measurement results in absolute (non-normalized) concentrations and the value of local mass thickness. Examples of quantitative analysis are presented and an extension to single crystal films is discussed.