Abstract
Atomic force microscopy (AFM) has recently demonstrated a mighty potential in the domain of nanolithography. Particularly, AFM nano-oxidation has been established as a reliable and routine technique for nanostructure and nanodevice fabrication, owing to its advantages of wide range of applicable samples, operation under ambient conditions and nanoscale resolution. We have employed AFM nano-oxidation to produce a variety of nickel oxide nanostructures by applying a negative bias to a conductive tip. A minimum oxide dot width of about 35 nm was achieved by this technique. After a dip in diluted nitric acid solution, the unoxidized nickel film was etched away and the oxide patterns were preserved. The nickel oxide patterns were then used as catalytic templates and the selective growth of vertically aligned carbon nanotubes by inductively coupled plasma chemical vapor deposition (ICP-CVD) was realized. Besides, the nickel oxide patterns were also used to grow silicon oxide nanowires through a vapor-liquid-solid reaction. In addition, it was found that the average diameter of carbon nanotubes or silicon oxide nanowires decreased as the average size of the nickel oxide dots was reduced. The present technique can used effectively to control the position and the diameter of carbon nanotubes or oxide nanowires.