Molecule corrals as templates for the formation of metal and silicon nanostructures

Gold and silicon nanostructures have been produced by condensing vacuum-evaporated materials and semiconductors onto nanometer-sized etch-pit templates preformed on the surface of highly oriented pyrolytic graphite. Billions of monodispersed monolayer-deep etch-pit templates, or "molecule corrals", can be produced in a range of diameters from a few to hundreds of nanometers due to the linear etch rate of carbon atom removal as a function of time. Evaporation and subsequent annealing of gold and silicon have resulted in the formation of metal and semiconductor nanostructures on the graphite basal plane. The size and shape of the nanostructures were examined using scanning tunneling microscopy, and the total coverage of the nanostructures and other chemical properties were examined using X-ray photoelectron spectroscopy. By varying the ratio of the total amount of material evaporated to the diameter of the etch-pit templates, three distinct types of metal nanostructures were observed to form on the molecule corral templates: rings, disks, and mesas. This method of producing nanostructures is a process that is inherently parallel and allows direct control over the final diameters and shapes (in two and three dimensions) of the nanostructures formed.