Effect of the spatial distribution of SiO2 thickness on the switching behavior of bistable MOS tunnel structures

Simulations of the reverse current-voltage characteristics of an Al/l-3 nm SiO2/n-Si tunnel structure are carried out, considering the spatial non-uniformity of oxide thickness. In a certain range of average thickness, these characteristics are S-shaped, exhibiting thereby a bistability. The shift of the turn-on and holding voltages related to the thickness deviation is predicted. The electric overload leads to the displacement of switching voltages as if the deviation of oxide thickness had became larger. Supporting experimental data are also provided.