Atomic force microscope for measuring properties of dielectric and insulating layers

摘要

An atomic force microscope that has an electrically-conductive probe and tip includes a feedback control circuit for generating a substantially constant, desired Fowler-Nordheim current between the probe tip and the surface of an electrically-conductive sample having a thin dielectric or insulating film thereon. The feedback circuit maintains the desired Fowler-Nordheim current flow between the probe tip and the sample by adjusting the bias voltage applied to the probe tip, and by tracking and using the changes in the applied bias voltage to provide a measure of the thickness, electrical conductivity or other electrical property of the film.