Method of measuring a surface profile using an atomic force microscope

Abstract

An atomic force microscope is preferably used to observe a sample surface and measure a surface profile of a sample by making use of interatomic forces existing between a probing tip and the sample surface. The atomic force microscope includes a cantilever having a probing tip, a laser diode for emitting a laser beam, a lens for focusing the laser beam emitted from the laser diode on the cantilever, and a photodiode for detecting a light beam reflected from the cantilever to thereby detect the amount of deflection of the cantilever. The atomic force microscope further includes a mechanism for finely moving one of a sample and the cantilever in three different directions, and a controller or computer for controlling the mechanism and for imaging the sample surface based on the amount of deflection of the cantilever at a plurality of locations of the sample surface. By this construction, after measurement of the sample surface at a first location thereof, the sample is moved away from the probing tip by a given length and is further moved relative to the probing tip so that the probing tip is positioned above a second location of the sample. Thereafter, the sample is further moved towards the probing tip at the second location by a length substantially equal to the given length. The movement of the sample is repeated until measurements of the sample surface at the plurality of locations thereof are completed.