Theoretical Approaches of Mobile Ions Density Distribution Determination

Abstract

Nevertheless, none of the experimental techniques so developed has been used to determine the density distribution of mobile ions. However, a few earlier theoretical attempts have been made in this direction, which are reviewed in this chapter. Besides, our empirical approaches are presented that can be used to determine the equilibrium density distribution of the mobile ions within the oxide of the MOS structures. The first approach has been investigated by using a general expression and experimental data before and after the drift takes place of the ions from one end to the other under the thermal–electric stress. However, the second approach is based on an empirical expression that has been derived for the total ion concentration in terms of the flat-band voltage shifts one before and another after thermal electric stress under different assumed distribution and thereafter comparing the computing values with experimental ones. Almost results up with the distribution of ion are Gaussian. Finally, our numerical approach to simulate the mobile ions density distribution; by solving a partial differential equation governing the ions kinetic is also presented.