Surface charging of silicon dioxide/silicon structures

It has been shown that it is possible to charge the surface of SiO₂ with a cantilever and to detect the resulting potential with the Kelvin option of an AFM. The surface charging with negative voltages is more effective than with positive voltages. The maximum of the potential depends on the charging voltage and the charging time. The surface potential shows a transient decay and a spread of the width w with relaxation times of about 30 h at room temperature. Due to the long time stability and the possibility to charge the surface in opposite direction an application as surface charge memory device is conceivable.