Rapid interface parameterization using a single MOS conductance curve

Figures are presented for finding interface trap density D_it capture probability c_p, and interfacial broadening σ_s, from a single curve of small-signal MOS interface trap conductance G_it/ω vs either band bending ν_s, or frequency f[ω = 2πf]. Almost no computation is necessary. An additional figure allows the depletion layer capacitance to be determined if the oxide capacitance and the measured capacitance at the maximum value of G_it/ω are known.The extension to G_it/ω vs ν_s, curves is a convenience. Parameters throughout the bandgap can be obtained from measurements at fewer frequencies than are needed for construction of accurate G_it/ω vs f curves. Economy also results because data usually are obtained by sweeping gate bias at selected frequencies. Construction of G_it/ω vs ν_s curves from the data is simpler than G_it/ω vs f, particularly if ν_s is measured directly.The information needed from the G_it/ω curve is the maximum value of G_it/ω and the width of the peak at an arbitrary fraction of its maximum value, fw. In addition, for capture probability only, the frequency and band bending at the peak maximum are needed, as well as the bulk doping.The method assumes validity of the Gaussian approximation to broadening of the conductance peak. Comparison of the parameters obtained for several choices of fw allows a check of this assumption, which usually is valid for MOS devices.