Kelvin probe microscopy (KPM) is a specialized atomic force
microscopy technique in which long-range Coulomb forces between a
conductive atomic force probe and a specimen enable the electrical
potential at the surface of a specimen to be characterized with high
spatial resolution. KPM has been used to characterize nonconductive
materials following their exposure to stationary electron beam
irradiation in a scanning electron microscope (SEM). Charged beam
irradiation of poorly conducting materials results in the trapping of
charge at either preexisting or irradiation-induced defects. The
reproducible characteristic surface potentials associated with the
trapped charge have been mapped using KPM. Potential profiles are
calculated and compared with observed potential profiles giving insight
into the charging processes and residual trapped charge
distributions.