Fabrication of gold nanostructures on graphite using atomic force microscope

Various nanostructures are created on graphite in air through the field-induced deposition of gold atoms from the gold-coated tip of atomic force microscope (AFM). The nanolithography controlling system we developed makes it possible to fabricate arbitrary complicated patterns and to optimize the deposition conditions fast and easily. We found that gold mounds can only be created by tip-negative pulses within the pulsed voltage range of +/-20 V, 0.2 - 300 msec, and the size of gold mounds and the threshold voltages are highly dependent on the geometry of Au-coated tip. Our results support the mechanism of field evaporation of negative gold ions.