STM-BASED NANOPATTERNING OF SILICON NANOPARTICLE FILMS

Nanolithography using the scanning tunneling microscope (STM) can be used on systems where the traditional X-ray and electron beam techniques have reached their limits. On hard materials such as silicon however, STM nanopatterning is difficult to achieve and has so far not been applied for lithography purposes. A solution to the problem is the use of templates consisting of silicon nanoparticles rather than single crystals or continuous thin films. It will be shown that STM-based nanolithography of silicon nanoparticle films can be performed in ultrahigh vacuum (UHV). Silicon atoms are effectively removed by field evaporation from the nanoparticles leading to nanopatterned dark areas on the grey template. In addition, clusters can be fused together leading to 'white' areas on the grey background. By variation of the tunneling conditions, letters or other nanopattem can be written both in 'black' and 'white' on the same template. Nanoindentations of various kinds can be performed which opens the possibility to use silicon nanoparticle templates for nanolithography applications.