Chemical vapor deposition of nanometer-size aluminum features on silicon surfaces using an STM tip

We have deposited aluminum (Al) features on silicon (Si) surfaces using the lectron beam and electric field produced at the tip of a scanning tunneling microscope (STM), in both tunneling and field emission modes. Lines as small as 3 nm in width have been produced on crystal Si(001). Al deposition is accomplished by exposing the tip-sample junction to trimethylaluminum (TMA) gas while tunneling. The electron beam of the STM tip dissociates the TMA molecules adsorbed on the surface, resulting in the production of surface-bound Al and hydrocarbon gas. Independent Auger electron spectroscopy studies of the electron induced deposition of Al from TMA shows nearly pure Al deposits.