Growth of horizontally aligned single-walled carbon nanotubes on anisotropically etched silicon substrate

Abstract

Directional controllability of single-walled carbon nanotubes (SWNTs) is an important issue for future nanoelectronics applications. For direct integration of carbon nanotubes with modern electronics, aligned growth of carbon nanotubes on SiO(2)/Si is desirable. We developed a new method to horizontally align SWNTs directly on SiO(2)/Si substrate by creating trenches on Si(100) through anisotropic etching followed by thermal oxidation. The V-shaped trenches highly improved the alignment of SWNTs and the degree of alignment is comparable to the step-templated alignment of carbon nanotubes on crystals. The trenches also improved the density of aligned nanotubes due to the combination of "trench-guided" and gas-flow guided alignment. Our new insights on carbon nanotube alignment on SiO(2)/Si will greatly contribute to future large-scale nanoelectronic applications.

Drawing Circuits with Carbon Nanotubes: Scratch-Induced Graphoepitaxial Growth of Carbon Nanotubes on Amorphous Silicon Oxide Substrates

“…As shown in the Supplementary Information Figure S5, no shift in Si 2p peak has observed in trench structures made with conventional photolithography and etching process. The XPS results determinately highlight the difference between this work and the previous reports by Orofeo and colleagues1112. While the driving force for the alignment in the previous work is purely geometrical constriction, favorable atomic rearrangement was added to the geometrical constriction (that match with the size of SWNT) in case of scratch-induced alignment.…”

“…Several attempts have been made to prepare aligned SWNTs on noncrystalline substrates. Aligned growth using external forces, such as electric fields or gas flows, has been demonstrated, and alignment using substrate modification techniques, such as lithographically patterned trenches, showed potential for success1112. However, a cost-effective method that permits the controlled growth of 1-D nanostructures on amorphous substrates is required for practical applications.…”

State of the Art of Single‐Walled Carbon Nanotube Synthesis on Surfaces

“…Surface directed growth mode essentially relies on the anisotropic van der Waals interactions between SWNT and various surface structures of substrate, including the crystallographic lattice (Figure c), faceted nano‐steps (Figure e) and etched trenches . Accordingly, it can be divided into lattice directed and nano‐step directed growth modes, which are capable to prepare aligned SWNT arrays with high density.…”

Nanoscratch technique for aligning multiwalled carbon nanotubes synthesized by the arc discharge method in open air

“…Vertical and horizontal alignment of CNTs is commonly attained by CVD techniques during synthesis 12,13 and by post-treatments. [14][15][16] Aligned MWCNTs using arc discharge under a controlled atmosphere of N 2 has been demonstrated. 17 The present work demonstrates in-situ synthesis of densely packed and * Author for correspondence (prathap@iitm.ac.in) horizontally aligned high-quality MWCNTs using the arc discharge method with the help of a metal scraper in an open air.…”