NANOSTRUCTURE FABRICATION USING LASER FIELD ENHANCEMENT IN THE NEAR-FIELD OF A SCANNING TUNNELING MICROSCOPE TIP

The scanning tunneling microscope (STM) has been combined with laser e xcitation and was used for modification of metal surfaces in air. This technique enables processing of structures with a lateral resolution of approximately 10 nm. The form of the created features ranges from c raters and ditches to hillocks. The process has been demonstrated on g old and gold/palladium substrates by utilization of tungsten, silver, and platin/iridium tips. Using pure silver tips or silver-coated tungs ten tips, a transfer of tip atoms to the substrate occurred. In the ca se of uncoated tungsten tips, we observed substrate evaporation and su rface grain reorganization at low laser intensities, respectively. No distortion of the employed tips during the structuring process was obs erved. Several future oriented applications are conceivable, such as, for example, high density data storage and fresnel optics for x rays. (C) 1996 American Institute of Physics.