Scanning Probe Microscopy (SPM) is being developed as a possible solution to the problems inherent with analyzing the nanometer scale electronic properties of ULSI integrated circuits. Scanning Kelvin Probe Microscopy (SKPM) and Scanning Capacitance Microscopy (SCM) are both being developed to provide two dimensional dopant profiles of semiconductor devices. SKPM can also determine surface potentials, work functions, dielectric properties, and capacitance.

SKPM is based on the concept of Kelvin probe oscillating capacitor work function measurements. The small capacitance area of the SKPM tip and the high resistance of the system produce difficulties in monitoring and minimizing the current in the system. SKPM solves this problem by utilizing the force monitoring capability of the SPM to minimize the Kelvin force instead of the current. An AC voltage applied to the cantilever produces a DC force and AC forces at the AC frequency and the first harmonic of the AC frequency.