Formation and thermal stability of sub-10-nm carbon templates on Si(100)

We report a lithographic process for creating high-resolution (<10nm) carbon templates on Si(100). A scanning electron microscope, operating under low vacuum (10−6mbar), produces a carbon-containing deposit (“contamination resist”) on the silicon surface via electron-stimulated dissociation of ambient hydrocarbons, water, and other adsorbed molecules. Subsequent annealing at temperatures up to 1320K in ultrahigh vacuum removes SiO2 and other contaminants, with no observable change in dot shape. The annealed structures are compatible with subsequent growth of semiconductors and complex oxides. Carbon dots with diameter as low as 3.5nm are obtained with a 200μs electron-beam exposure time.