STABILITY OF DENSELY CONTACT-ELECTRIFIED CHARGES ON THIN SILICON-OXIDE IN AIR

By changing the polarity of charged trap sites; we investigated the st ability of densely contact-electrified charges on thin silicon oxide i n air using a modified atomic force microscope. For usual silicon oxid es with positively charged trap sites, a stable state is obtained only for negative charge deposition, while for modified silicon oxides wit h negatively charged trap sites, a stable state is obtained only for p ositive charge deposition. As a result, we concluded that charged trap sites make densely contact-electrified charges with the same polarity unstable due to the strong Coulomb repulsive force.