ABSTRACT
Kelvin probe microscopy (KPM) has been used to characterise silicon dioxide exposed to gallium ion irradiation in a focused ion beam (FIB) miller. Significant localised residual charging is observed within the gallium implanted micro-volumes of non-conductive materials both prior to and following the onset of sputtering. Charged beam irradiation of poorly conducting materials results in the trapping of charge at either pre-existing or irradiation induced defects, thereby inducing a localised electric field within the irradiated micro-volume of specimen. Scanning probe microscopy techniques enable non-destructive three dimensional high spatial resolution real space images of surfaces via detection of local interactions between the specimen surface and a sharp probe. KPM directly confirms for the first time significant residual surface potential resulting from gallium ion beam irradiation in a FIB system. Gallium ion implantation produces reproducible characteristic changes in the surface topography due to sputtering of the surface.
