Quantitative two-dimensional dopant profiling of abrupt dopant profiles by cross-sectional scanning capacitance microscopy

The scanning capacitance microscope (SCM) is capable of quantitative two-dimensional carrier and dopant density mapping with nanometer scale spatial resolution. The method can be applied to either the top or the cross-sectional surface of a silicon sample. The quantitative inversion of SCM data to carrier or dopant density is achieved using a quasi-one-dimensional model. Cross-sectional SCM measurements have been performed on samples that have abrupt dopant density steps. The dopant density in these samples systematically varies from 1017 to 1020 cm−3. The cross-sectional measurements provide a means to directly compare the SCM results with vertical secondary ion mass spectroscopy (SIMS) profiles. A spatial resolution of approximately 25 nm is achieved. A first order quantitative agreement between the SCM and the SIMS profiles is found.