Enhanced etching of silicon dioxide guided by carbon nanotubes in HF solution

This paper describes a new method to create nanoscale SiO₂ pits or channels using single-walled carbon nanotubes (SWNTs) in an HF solution at room temperature within a few seconds. Using aligned SWNT arrays, a pattern of nanoscale SiO₂ channels can be prepared. The nanoscale SiO₂ patterns can also be created on the surface of three-dimensional (3D) SiO₂ substrate and even the nanoscale trenches can be constructed with arbitrary shapes. A possible mechanism for this enhanced etching of SiO₂ has been qualitatively analysed using defects in SWNTs, combined with H₃O⁺ electric double layers around SWNTs in an HF solution.