A force-based scanning Kelvin probe microscope has been applied to the problem of dopant profiling in silicon. Initial data analysis assumed the detected electrostatic force couples the sample and only the tip at the end of a force sensing cantilever. Attempts to compare measurements quantitatively against device structures with this simple model failed. We have determined a significant contribution arises from the electrostatic force between the sample and the entire cantilever, which depends

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... trongly upon the relative size of the tip, cantilever, and lateral inhomogeneities in the surface topography and material composition of the sample. We present actual and simulated measurements which demonstrate the characteristic signature of this effect.