Charge storage in the nitride layer of MNOS structures

It can be found from a simultaneous study of MNOS-structures having equal oxide thicknesses, that charge in the structure can penetrate deep in the nitride (even deeper than 200 Å), and that the penetration depth increases with the nitride field strength. Using this method, it can be proved that the decrease of flat-band voltage is due not only to a charge leakage but at the same time to a redistribution of charges in the nitride. The true nitride charge logarithmically decreases in time, while the depth of the center of charge logarithmically increases.