Growth and chemical modification of silicon nanostructures templated in molecule corrals: Parallels with the surface chemistry of single crystalline silicon

摘要

Molecule corrals having diameters of 30-50 nm were created on highly oriented pyrolytic graphite (HOPG) using cesium ion bombardment. The molecule corrals were used as templates to grow silicon nanostructures by physical vapor deposition (PVD). The nanostructures could be grown with control over geometry (rings and mesas), and size distribution. In addition, transmission electron microscopy (TEM) results suggest that the silicon nanostructures are most likely polycrystalline.The chemical modification of these silicon nanostructures with nitrobenzene was compared to that of clean and hydrogen-terminated single crystalline silicon. X-ray photoelectron spectroscopy (XPS) of the modified nanostructures showed peaks located at 398.9 eV, 400.4 eV, and 402.1 eV for the N 1s region, which are consistent with those observed on a Si(100) single crystal. The chemical modification was further characterized by the presence of nitrogen-containing peaks in TOF-SIMS spectra. We conclude that the reaction of nitrobenzene on silicon nanostructures provides evidence that the reactivity of the nanostructures is similar to that of hydrogen-terminated Si(111) and Si(100).