AUGER LINES SUPPRESSION

This operation can be performed by one of the methods based on the analog differentiation mode of N(E).

In the first method the sample is disconnected from the ground and its voltage is modulated with the same frequency as the analyzer's scanning voltage: . This does not change the kinetic energy of IL electrons (does not influence their position within the spectrum) and they are detected as usual. Meanwhile, the kinetic energy of Auger electrons depends on exact value of .

Changing the phase and the magnitude of , it is possible to completely supress the AC component of Auger related electron current on the analyzer's exit. No matter that the DC component of the analyzer's current contains Auger electrons, only ILs, plasmon peaks and the EBE are present in the detected signal after its differentiation.

In the second method the sample is grounded and the scanning is done with the unmodulated analyzer's voltage Va=Vs(t). However, the electron gun cathode voltage is modulated: . The magnitude of modulation is much smaller than Vp, therefore the operation of the gun is not disturbed. The energetic positions of IL and the EBE line depend on exact value of Vp, contrary to the position of Auger lines and analyzer's window. Because of this, the AC component of the current on the analyzer's exit is completely formed by the electrons of ionization spectrum, plasmon lines and EBE.