Direct deposition of electronic materials with thermal DPN

In recent years there has been a significant effort to improve or augment lithographic techniques for electronic device fabrication. Although improvements in ultimate resolution have been a central goal, other goals have also been pursued that may be important avenues to advance device fabrication. These alternate objectives include reduction of toxic by-products ("green chemistry"), integration of disparate materials into a single structure (e.g., organic and inorganic), and production or prototyping of low numbers of integrated circuits at relatively low unit cost. Progress towards all these goals is found in a new lithographic technique, thermal Dip Pen Nanolithography (tDPN). In tDPN (Figure 1), an atomic force microscope (AFM) cantilever is custom fabricated to include a heater directly above the tip. The tip is then coated with an "ink" that is solid at room temperature but that can be melted by the integrated heater. When the ink is melted, it flows onto the surface and solidifies, thereby allowing arbitrary patterns to be written.