Laser-assisted deposition of nanometer structures using a scanning tunneling microscope

Nanometer-scale deposits as small as 1 nm have been made on graphite surfaces using laser-induced multiphoton fragmentation and ionization of trimethylaluminum (TMA) molecules in the tunneling junction of a scanning tunneling microscope. Laser radiation generates ions, which are guided to the surface by the electric field between the tip and the surface. The resolution of this technique is limited by the extent of the field in the tunneling junction.