Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > Writing between the lines: Nano-patterning on silicon: a single compound reacts with silicon surface to form perpendicular molecular lines

Figure 1: Scanning-tunneling microscopy image of acetophenone lines on a silicon surface. The lines of acetophenone can be seen as a bright orange line against the blue background of the surface.
Figure 1: Scanning-tunneling microscopy image of acetophenone lines on a silicon surface. The lines of acetophenone can be seen as a bright orange line against the blue background of the surface.

Abstract:
Miniaturization of microprocessor components can be achieved by two opposing methods: so-called top-down and bottom-up approaches. In top-down approaches, smaller and smaller circuits are produced by optimizing and improving upon larger scale patterning technology. Bottom-up approaches rely on the assembly of single molecule building blocks to produce patterns—ultimately, the pattern size that can be achieved by either method will coincide. One potential bottom-up method creates molecular lines—and ultimately patterns—by reacting molecules with the atoms at the surface of a material. The major challenge for researchers is to control the direction in which these lines grow.

Writing between the lines: Nano-patterning on silicon: a single compound reacts with silicon surface to form perpendicular molecular lines

Japan | Posted on December 26th, 2008

Most microprocessor devices are produced from silicon, so patterning of silicon surfaces is of high importance. Writing in the Journal of the American Chemical Society1, Md. Zakir Hossain and co-workers from the RIKEN Advanced Science Institute in Wako have shown that reaction of a single compound—acetophenone—with a silicon surface can result in the growth of straight lines of molecules (Fig. 1).

The surface of the silicon comprises pairs of silicon atoms, known as dimers, arranged in parallel rows. Various molecules have been previously shown to form straight lines by reaction with the surface of the silicon—either along the dimer rows or perpendicular to them. Importantly, the direction of growth of these lines depended—until now—only on the molecule reacting with the silicon surface.

The silicon surface is prepared by reaction with atomic hydrogen, which results in silicon hydrogen bonds over most of the surface. However a few silicon atoms do not react, forming so called dangling bond sites, which are very reactive. Acetophenone molecules react with the dangling bond and go on to create a new dangling bond site at an adjacent silicon dimer. This sets up a chain reaction and produces a molecular line. The direction in which the lines of molecules grow depends on whether the new dangling bond is formed in a silicon dimer in the same row or a parallel row.

The distance between silicon dimers in the same row or those in adjacent rows is different, and there is a consequent energy difference in the two possible growth directions. "Acetophenone happens to have a geometry that means it can grow lines in either direction," explains Hossain. "Creation of a chiral center upon adsorption also seems to play important role in producing lines in both directions, which we believe will provide opportunities to control the growth direction."
Reference

1. Hossain, M. Z., Kato, H. S. & Kawai, M. Self-directed chain reaction by small ketones with the dangling bond site on the Si(100)-(2 x 1)-H surface: acetophenone, a unique example. Journal of the American Chemical Society 130, 11518-11523 (2008).

The corresponding author for this highlight is based at the RIKEN Surface Chemistry Laboratory

####

For more information, please click here

Copyright © Riken

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

article

Related News Press

News and information

Virginia Tech physicists propose path to faster, more flexible robots: Virginia Tech physicists revealed a microscopic phenomenon that could greatly improve the performance of soft devices, such as agile flexible robots or microscopic capsules for drug delivery May 17th, 2024

Gene therapy relieves back pain, repairs damaged disc in mice: Study suggests nanocarriers loaded with DNA could replace opioids May 17th, 2024

Shedding light on perovskite hydrides using a new deposition technique: Researchers develop a methodology to grow single-crystal perovskite hydrides, enabling accurate hydride conductivity measurements May 17th, 2024

Oscillating paramagnetic Meissner effect and Berezinskii-Kosterlitz-Thouless transition in cuprate superconductor May 17th, 2024

Chip Technology

Diamond glitter: A play of colors with artificial DNA crystals May 17th, 2024

Oscillating paramagnetic Meissner effect and Berezinskii-Kosterlitz-Thouless transition in cuprate superconductor May 17th, 2024

Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024

Utilizing palladium for addressing contact issues of buried oxide thin film transistors April 5th, 2024

Discoveries

Virginia Tech physicists propose path to faster, more flexible robots: Virginia Tech physicists revealed a microscopic phenomenon that could greatly improve the performance of soft devices, such as agile flexible robots or microscopic capsules for drug delivery May 17th, 2024

Diamond glitter: A play of colors with artificial DNA crystals May 17th, 2024

Finding quantum order in chaos May 17th, 2024

Advances in priming B cell immunity against HIV pave the way to future HIV vaccines, shows quartet of new studies May 17th, 2024

Announcements

Virginia Tech physicists propose path to faster, more flexible robots: Virginia Tech physicists revealed a microscopic phenomenon that could greatly improve the performance of soft devices, such as agile flexible robots or microscopic capsules for drug delivery May 17th, 2024

Diamond glitter: A play of colors with artificial DNA crystals May 17th, 2024

Finding quantum order in chaos May 17th, 2024

Oscillating paramagnetic Meissner effect and Berezinskii-Kosterlitz-Thouless transition in cuprate superconductor May 17th, 2024

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project