Nanoscale Structuring of Gold Surfaces with Laser Manipulated Neutral Cesium Atoms

Atom lithography was invented in the last decade at Bell Labs, where the possibility of producing nanostructures with laser manipulated neutral Na atoms was demonstrated for the first time [1]. Atom lithography [2] is in principle similar to optical lithography, the main difference being that the roles of light and matter are reversed each other. While in optical lithography matter (material masks) is used to pattern a light beam (which is then used to impress the photoresist), in atom lithography nanopatterns are produced through interaction of a neutral atom beam with a “light mask”, a suitable configuration of stationary e.m. fields quasi-resonant with an atom transition. Such interaction leads to space segregation of the beam into regular arrays of atoms, which can be used either for direct deposition or to impress a particle sensitive resist. The process keeps the advantageous possibility of large-area patterning typical of conventional lithography, while using a virtually defect-free mask able to produce regular nanopatterns with interferometric precision. Furthermore, the process is not limited by diffraction effects, as the de Broglie wavelenght of an atomic beam is well below the nanometer range.