Nanolithographic Patterning of Metal-films With a Scanning Tunneling Microscope

We have developed a new technique, which allows to pattern thin evaporated Au films at the nanometer scale with a scanning tunnelling microscope (STM). The STM tip is used to expose a very thin layer of omega-tricosenoic acid, which has been deposited on top of the Au films using the Langmuir-Blodgett technique and acts as an electron sensitive, negative resist. We have fabricated narrow Au lines with a width down to 15 nm and we have checked that our STM lithography does not degrade the metallic properties of the Au films. The power of our lithographic patterning technique is nicely illustrated by the fact that we can attach electrical gold contacts to a small bundle (total diameter of 50 nm) of carbon nanotubes (''Buckey tubes'') and measure the electrical resistance of the bundle as a function of temperature and magnetic field