DISSIPATION OF CONTACT-ELECTRIFIED CHARGE ON THIN SI-OXIDE STUDIED BY ATOMIC-FORCE MICROSCOPY

A microscopic contact electrification on a thin silicon oxide was done by an atomic force microscope (AFM) with a biased conductive cantilever coated with Au/Cr. As a result, a good reproducibility was obtained for the first time, and the sign of deposited charges was controlled successfully by the sign of bias voltage V-c. Negative charges were deposited more easily than positive charges, and the number of deposited charges also seems to be controllable. After the controlled contact electrification, the charge dissipation on the thin silicon oxide was investigated microscopically by a non-contact DC mode detection of the electrostatic force with the AFM biased by the voltage V-s. As a result, some differences were found between the charge dissipations of positive and negative charges and under the repulsive and attractive force measurements.