Contribution of GEANT4 to the determination of sensitive volumes in case of high-integrated RAMs

This paper deals with the use of short range beams in order to measure the sensitive thickness of devices. In the case of a Hitachi 4-Mbit SRAM, σ(E) measurements have been compared to GEANT 4 calculations, taking into account the effects of the overlayers. The analysis of the experimental data at two bias levels has pointed out that σ(E) is directly correlated with the energy deposited in SV for low ranges, on the other hand charge collection mechanisms have a strong impact for longer ranges.