Fabrication of vertically aligned silicon nanotubes using nanosphere beads as the mask and Bosch process

In this paper, we report that silicon nanotubes or hollow nanopillars can be fabricated by a series of standard microfabrication processes, specifically by an ambient temperature Bosch process using the nanosphere beads as the mask. The dimensions of the Si nanotubes can be readily tuned, with a diameter from 10s of nanometers to 100s of nanometers with a high aspect ratio. The as-fabricated Si nanotube surfaces assume super hydrophobicity and have an excellent optical absorption capability, suggesting their potential applications in the fields of life science, biomedical engineering, nanomedicine, solar energy harvesting, and energy storage.