Localized synthesis of horizontally suspended carbon nanotubes

Horizontally suspended carbon nanotube (CNT) forests and bundle arrays were grown locally from selected trench sidewalls with the assistance of microheaters integrated on the silicon substrate. The patterned iron (Fe) catalyst layer was deposited onto these trench sidewalls by the tilted electron beam evaporation through a shadow mask placed on top of the trenches. Only local areas of the substrate were heated to high temperatures for the CNT growth by integrated microheaters, while most other areas remained at much lower temperatures, improving the process compatibility of the CNT growth with CMOS semiconductor technologies. The length and quality of the CNTs display a strong dependence on the local growth temperatures, and generally long and high-quality CNTs are grown in the high temperature regions. (C) 2013 Elsevier Ltd. All rights reserved.