Comparison of Bulk-Oxide Trap Models: Lumped Versus Distributed Circuit

Lumped- and distributed-circuit models for bulk-oxide traps are compared in terms of their fitting of p and n-type InGaAs MOS dispersion data. It is shown that the lumped-circuit model produces a distinct curvature in the capacitance versus log (frequency) plot-inconsistent with MOS data. Distributed-circuit model is able to fit both capacitance and conductance dispersions with a single, uniform oxide trap density, but the lumped-circuit model cannot. It is also shown that Hasegawa and Sawada's lumped-circuit model with an exponentially decaying distribution of border traps deviates even farther from the dispersion data.