It has been shown that both RF plasma and plasma-jet treatments led to the creation of electron traps in the bulk of SiO2 film. As a result, it is possible to increase the breakdown voltage of a metal-oxide-semiconductor (MOS) structure when the breakdown probability is significantly decreased. It has been found that injection treatment of MOS structures with thermal SiO2 film allows control of the statistical distribution of charge defects, and thus the mean charge injected into the dielectric to breakdown is increased. The modification of MOS devices having a gate dielectric of SiO2/phosphosilicate glass by Fowler-Nordheim (FN) electron injection taking place in high-fields was also studied. Constant-current FN electron injection from the silicon substrate and the metal electrode was used to modify the charge state of the MOS structure.