Transport in Thermal Dip Pen Nanolithography

The manufacture of nanoscale devices is at present constrained by the resolution limits of optical lithography and the high cost of electron beam lithography. Furthermore, traditional silicon fabrication techniques are quite limited in materials compatibility and are not well-suited for the manufacture of organic and biological devices. One nanomanufacturing technique that could overcome these drawbacks is dip pen nanolithography (DPN), in which a chemical-coated atomic force microscope (AFM) tip deposits molecular ‘inks’ onto a substrate [1]. DPN has shown resolution as good as 5 nm [2] and has been performed with a large number of molecules, but has limitations. For molecules to ink the surface they must be mobile at room temperature, limiting the inks that can be used, and since the inks must be mobile in ambient conditions, there is no way to stop the deposition while the tip is in contact with the substrate. In-situ imaging of deposited molecules therefore causes contamination of the deposited features.