Perturbation approach of the injection effect on the electron-beam-induced current efficiency in lightly doped semiconductors

The influence of the injection on the electron-beam-induced current (EBIC) collection efficiency η has been examined through a perturbation approach, assuming no recombination in the depletion zone but with a surface recombination speed which is independent from injection. This calculation investigates the hole (electron) concentration spatial distribution in the depletion zone as well as the consequences of the electric field variation in that zone, caused by the injection, on the EBIC efficiency of the lightly doped semiconductors. The results show that such an effect is far from weak. The EBIC experiments performed on Au-n-type Si Schottky diodes quantitatively agree with our model results. Finally, we come to the conclusion that the effect of the electron field variation on the collection efficiency is as important as the modification in the carrier recombination at higher levels.