  Scanning Surface Potential Microscopy (SSPM) is one of the most widely used
techniques for the characterization of electrical properties at small
dimensions. Applicability of SSPM and related electrostatic scanning probe
microscopies for imaging of potential distributions in active micro- and
nanoelectronic devices requires quantitative knowledge of tip surface contrast
transfer. Here we demonstrate the utility of carbon-nanotube-based circuits to
characterize geometric properties of the tip in the electrostatic scanning
probe microscopies (SPM). Based on experimental observations, an analytical
form for the differential tip-surface capacitance is obtained.
