Question

Why doesn't the electron beam current itself strongly influence the measured Electron Beam Induced Current (EBIC) current?

Answer 1

When an electron beam of a scanning electron microscope (SEM) impinges on an N-P junction, the generation of electron-hole pairs by impact ionization causes a characteristic short circuit current to flow i.e., EBIC.

Electron beam of an SEM is very small, So beam current is not significant to consider. Due to this reason electon beam is focused and scanned across the sample, and variations in the induced EBIC are used to map the electronic activity of the sample.