Practical quantitative scanning microwave impedance microscopy

Scanning microwave impedance microscopy (sMIM) is an emerging technique that has the potential to displace conventional scanning capacitance microscopy (SCM), and other electrical scanning probe microscopy (SPM) techniques, for the profiling of dopants in semiconductor samples with sub-micron spatial resolution. In this work, we consider the practical application of sMIM for quantitative measurement of the dopant concentration profile in production semiconductor devices. We calibrate the sMIM using a doped calibration sample prior to performing the measurements on an “unknown” production device. We utilize nanoscale C-V curves to establish a calibration curve for both n- and p-type carriers in a single reference and apply the calibration curve to an “unknown” device presenting the measurements in units of doping concentration. The calibrated results are compared to SRP measurements on the same area of the device.