Calibrated Scanning Capacitance Microscopy for Two-Dimensional Carrier Mapping of n-type Implants in p-doped Si-Wafers

In our previous work we showed that a reproducible monotonic relation between Scanning Capacitance Microscopy (SCM) signal and the sample doping is obtained under appropriate SCM operating conditions. In this work, we quantitatively determine the two-dimensional carrier distribution of an n-type ion-implanted collector region of an industrial transistor sample. As the structures were large enough so that tip geometry effects could be neglected, the SCM data were converted into a two-dimensional doping distribution via a simple lookup table, which was generated from a one-dimensional doping profile measured on a reference wafer. In case the depth distribution of carriers is unknown, we show that the lookup table can also be calculated and a calibration can be carried out using e.g. the substrate doping as reference point.