Atom Lithography With Metastable Helium

A bright metastable helium (He(*)) beam is collimated sequentially with the bichromatic force and three optical molasses velocity compression stages. Each He(*) atom in the beam has 20 eV of internal energy that can destroy a molecular resist assembled on a gold coated silicon wafer. Patterns in the resist are imprinted onto the gold layer with a standard selective etch. Patterning of the wafer with the He(*) was demonstrated with two methods. First, a mesh was used to protect parts of the wafer making an array of grid lines. Second, a standing wave of lambda=1083 nm light was used to channel and focus the He(*) atoms into lines separated by lambda/2. The patterns were measured with an atomic force microscope establishing an edge resolution of 80 nm. Our results are reliable and repeatable.