Modeling the transfer characteristic and harmonic distortion effects in scanning capacitance microscopy measurements

In this paper we investigate the dopant quantification error introduced in scanning capacitance microscopy measurements by the nonlinearity of the capacitance-to-voltage characteristic of MOS structures. The C-V response of the measurement set up is derived by finite element simulation and the systematic error introduced by signal processing is quantified by harmonic distortion analysis. It is shown that the investigated effect can lead to a systematic overestimate of the dopant concentration ranging from a factor of 2 up to a factor of 20, depending on the experimental conditions.