TAPPING ATOMIC FORCE MICROSCOPE WITH PHASE OR FREQUENCY DETECTION

摘要

A probe tip in an atomic force microscope is oscillated at a resonant frequency and at an amplitude setpoint and scanned across the surface of a sample at constant amplitude in intermittent contact with the sample. Changes in phase or in resonant frequency of the oscillating are measured to determine adhesion between the probe tip and the sample. The setpoint amplitude of oscillation of the probe is greater than 10 nm to assure that the energy in the probe lever arm is much higher than that lost in each cycle by the probe striking the sample surface so that the probe tip does not stick to the sample surface. Force dependent sample characteristics are determined by comparing data obtained at different tapping amplitude setpoints.