Aligned single-walled carbon nanotube growth on patterned SiO2/Si substrates

Abstract

Horizontally aligned single-walled carbon nanotubes (SWNTs) were fabricated on patterned SiO2/Si substrates with groove-and-terrace or half-cylinder structures by electron-beam lithography and reactive ion etching. Scanning electron microscopy observation reveals that the SWNTs were aligned in the direction parallel to the patterned structures and were preferentially grown along the edges of terraces or along the sidewalls of the half cylinders. The results are consistent with calculations obtained using the Casimir–Polder potential between the SWNTs and the patterned substrates. Using aligned SWNTs as multichannels, carbon nanotube field-effect transistors (CNT-FETs) were fabricated on the patterned SiO2/Si substrates. This method will be promising to control the directions of the SWNTs on SiO2/Si substrates.