The dynamics of space-charge accumulation in irradiated MOS capacitors

Publisher Website
Google Scholar
Abstract
An investigation into the radiation-induced charging of MOS capacitors using numerical simulation is reported. The results indicate that the high mobility of electrons in SiO2 films prevents accurate simulations from being carried out even for moderately short exposure times. This is so because of the small integrating time step (-14s) required to maintain the stability of the integrating routine for an assumed mobility of 2*10-3 m2 V-1 s-1. The importance of including in the simulations the effects of geminate/columnar recombination processes on the generation rate of electron-hole pairs is demonstrated. Finally it is shown that, in the absence of diffusion effects and thermal re-emission from traps, the trapped hole space-charge induced by energetic radiation in SiO2 will, for low fields at least, accumulate in an approximately rectangular distribution near the cathode, all the traps there being completely filled.