Field distribution and avalanche breakdown of trench MOS capacitors operated in deep depletion

Two-dimensional electric-field and avalanche breakdown calculations are presented for trench MOS capacitors operated in deep depletion. Breakdown calculations are based on the ionization-integral approach, with field values resulting from solutions of Poisson´s equation. Plots of breakdown voltage versus background impurity concentration, oxide thickness, and trench width are provided, which are recommended for first-order engineering calculations of semiconductor structures involving the deeply depleted trench capacitor as a breakdown-voltage-setting component. Calculations cover the range of 10¹⁴ to 10¹⁸ cm^-3 background impurity concentration and 0.01 to 5 mu m oxide thickness and apply to well-separated (i.e. noninteracting) rectangular trenches with widths equal to or larger than 0.2 mu m.