Electrostatic nanolithography on PVP films for patterning metal nanocrystals and fullerenes

Nanometric trench patterns have been drawn on polyvinylpyrrolidone films coated on Si substrates, employing an atomic force microscope using a conducting tip under a bias of −12 V with respect to the substrate ground and a moderate writing speed of 0.5 µm s−1. The obtained trenches have been used as nanomolds to create line patterns filled with Au nanocrystals (mean diameter, 3.5 nm). Importantly, scanning electron microscopy measurements showed that the region around the polymer trenches is subjected to an electric field stress from the tip. Thus the modified region was exploited in chemically adsorbing C60, as shown by electrical force microscopy and Raman spectroscopy measurements. The utility of the method is demonstrated by measuring the I–V characteristics of a nanopattern of C60.