Comment on “Broadening of metal-oxide-semiconductor admittance characteristics: Measurement, sources, and its effects on interface state density analyses” [J. Appl. Phys. 110, 114115 (2011)]

Low-temperature capacitance-voltage (C-V) characteristics of n-type In0.53Ga0.47As metal-oxide-semiconductor (MOS) capacitors, presented by Paterson et al. [J. Appl. Phys. 110, 114115 (2011)], are modeled by analytical and numerical calculations of the capacitance taking into account the slow response of neutral donors and interface traps to the measurement test signal. This model provides an explanation for the absence of the dip near flat band in the high frequency C-V characteristics, contrary to the prediction based on the ideal MOS capacitance. These calculations also show that a broad energy distribution of interface-traps can explain the broadening of the C-V curve.