Nondestructive dopant profile measurement and its quantitative analysis using the nanocapacitance–voltage method

We propose a new method that can quantitatively extract the dopant profile in a nondestructive manner using scanning capacitance microscopy (SCM) or a nanocapacitance–voltage $(nano-C–V)$ system. The method is based on a nanotip capacitor model, and not the common parallel-plate capacitor model. For the first time, we have physically analyzed a nanotip capacitor by considering the interaction between the air and a semiconductor and have calculated the full $C–V$ curves and the rate of capacitance change with bias $(dC/dV).$ We calculated the local $dC/dV$ curve that was matched to the experimental $dC/dV$ data. This quasi-three-dimensional modeling illustrates that the $C–V$ characteristics derived from the nanotip model are different from those of a conventional parallel-plate method. We found that the increase in capacitance in the inversion region (characterized by a double peak in the $dC/dV$ curve) is due to the quasispherical characteristics of the depleted layer generated by the nanotip located in the air. These results enable the quantification of dopant profiles in a step-by-step process using a one-dimensional inversion algorithm, and their subsequent comparison with a secondary ion mass spectroscopy profile.