IMAGING INTEGRATED-CIRCUIT DOPANT PROFILES WITH THE FORCE-BASED SCANNING KELVIN PROBE MICROSCOPE

A force-based scanning Kelvin probe microscope has been used to image dopant profiles in silicon for integrated circuit devices on a submicr on scale. By measuring the potential difference which minimizes the el ectrostatic force between a probe and surface of a sample, an estimate of the work function difference between the probe and surface may be made. To the extent that this work function difference is a consequenc e of the dopant concentration near the sample surface, doping profiles are inferred from the measurements. An overview of the measurement te chnique is presented, along with several examples of resulting dopant imaging of integrated circuits. (C) 1996 American Vacuum Society.