Deep-depletion breakdown voltage of silicon-dioxide/silicon MOS capacitors

The deep-depletion breakdown voltage of silicon-dioxide/ silicon MOS capacitors is determined by the ionization-integral method, with potential distributions computed by two-dimensional relaxation techniques. Calculations cover the range of substrate doping between 10¹⁴and 10¹⁸cm^-3and oxide thickness between 0.01 and 5.00 µm, providing plots of breakdown voltage versus substrate impurity concentration with oxide thickness as parameter. A universal and normalized criterion is derived for field uniformity in terms of the ratio of oxide thickness to the maximum (breakdown) width of the silicon depletion region: this ratio should be larger than 0.3 in order not to have field concentration around the edges of the metal plate.