Local stabilization of single-walled carbon nanotubes on Si(100)-2 × 1:H via nanoscale hydrogen desorption with an ultrahigh vacuum scanning tunnelling microscope

An ultrahigh vacuum scanning tunnelling microscope (UHV-STM) was used to modify the interface between isolated ≈10 Å-diameter single-walled carbon nanotubes (SWNTs) and the hydrogen-passivated Si(100) surface. Room-temperature UHV-STM desorption of hydrogen at the SWNT/H-Si(100) interface resulted in the local mechanical stabilization of tubes originally perturbed by the rastered STM tip under nominal imaging conditions. For the section of the SWNT contacted by depassivated Si, a topographic depression of 1.5 Å (1 Å) was measured in the case of parallel (nearly perpendicular) alignment between the tube axis and the Si dimer rows, in agreement with existing first-principles calculations. The compatibility of hydrogen-resist UHV-STM nanolithography with SWNTs adsorbed on H-Si(100) would enable the atomically precise placement of single molecules in proximity to the tube for the bottom-up fabrication of molecular electronic devices.