Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Sketching on silicon

Figure 1: Continuous molecular lines with perpendicular geometries can be drawn on silicon substrates using two different compounds that grow in different directions when they react with the surface atoms.
Reproduced with permission from JACS 129, 12304–12309 (2007). Copyright (2007) the American Chemical Society
Figure 1: Continuous molecular lines with perpendicular geometries can be drawn on silicon substrates using two different compounds that grow in different directions when they react with the surface atoms.
Reproduced with permission from JACS 129, 12304–12309 (2007). Copyright (2007) the American Chemical Society

Abstract:
Two different chemical compounds can be used to draw perpendicular molecular lines on the surface of silicon substrates

Sketching on silicon

Japan | Posted on February 1st, 2008

Silicon is the workhorse material of the semiconductor industry because it is on this element that the integrated circuits of modern microprocessor devices are built. In order to satisfy the ever-increasing speed and power demands of computing, the miniaturization of such electronic components is the focus of much research.

So-called top-down methods used to carve ever-smaller features into the surface of silicon wafers will result in performance benefits for a little longer, but there are size limits to which these structures can be practically reduced. An alternative fabrication approach, however, relies upon the bottom-up assembly of molecular building blocks to form nanoscale electronic components.

Now, Maki Kawai and colleagues from RIKEN's Discovery Research Institute in Wako, have discovered a way to ‘draw' perpendicular lines—made from different molecules—on silicon surfaces that comprise pairs of atoms, known as dimers, aligned in parallel rows1. Writing in the Journal of the American Chemical Society, they found that acetone—a small organic compound—readily forms straight molecular lines along the rows of silicon dimers on these substrates.

The silicon substrate was first exposed to atomic hydrogen, resulting in the formation of silicon-hydrogen bonds. A small number of the silicon atoms do not react, however, and these so-called ‘dangling-bond sites' are quite reactive and can form bonds with organic molecules. When an acetone molecule becomes fixed to the surface by reacting with a dangling-bond site, a new dangling-bond site is created in the adjacent silicon dimer in the row, setting off a chain reaction in which more acetone molecules bond to the surface to form a molecular line.

Kawai and co-workers went on to show that acetone lines can be grown from the ends of lines formed from other molecules on the same silicon surface. In contrast with acetone, molecules of a compound called allylmercaptan form lines in a direction perpendicular to the rows of silicon dimmers (Fig. 1). In this way, mutually perpendicular lines can be formed on these silicon surfaces, since their direction can be simply controlled by changing the gas feed to the surface.

Because dangling-bond sites can also be produced at predefined positions on the surface with a scanning tunneling microscope, the origin of the lines can be precisely controlled. The ability to form molecular arrays with carefully controlled geometries on a material around which the semiconductor industry revolves could have significant implications for the rapidly developing field of molecular electronics.

Reference

1. Hossain, Md. Z., Kato, H. S. & Kawai, M. Selective chain reaction of acetone leading to the successive growth of mutually perpendicular molecular lines on the Si(100)-(2x1)-H surface. Journal of the American Chemical Society 129, 12304-12309 (2007).

####

About Riken
RIKEN is one of Japan’s largest research organisations with institutes and centres in various locations in Japan (see www.riken.jp/engn/r-world/link/index.html). RIKEN’s 3000+ researchers publish several hundred research articles in top scientific and technical journals every year across a broad spectrum of disciplines in physics, chemistry, biology, medicine, earth science and in many areas of technology, and the number of articles is growing year on year.

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 News Press

News and information

Two-dimensional melting of hard spheres experimentally unravelled after 60 years: First definitive experimental evidence of two-dimensional melting of hard spheres April 21st, 2017

National Conference on Nanomaterials, (NCN-2017) April 21st, 2017

NanoMONITOR shares its latest developments concerning the NanoMONITOR Software and the Monitoring stations April 21st, 2017

Nanomechanics, Inc. Unveils New Product at ICMCTF Show April 25th: Nanoindentation experts will launch the new Gemini that measures the interaction of two objects that are sliding across each other – not merely making contact April 21st, 2017

Chip Technology

'Neuron-reading' nanowires could accelerate development of drugs for neurological diseases April 12th, 2017

Nanometrics to Announce First Quarter Financial Results on May 2, 2017 April 11th, 2017

AIM Photonics Presents Cutting-Edge Integrated Photonics Technology Developments to Packed House at OFC 2017, the Optical Networking and Communication Conference & Exhibition April 11th, 2017

Photonics breakthough paving the way for improved wireless communication systems: The work could bolster the wireless revolution underway with efficiencies several orders of magnitude April 5th, 2017

Discoveries

Two-dimensional melting of hard spheres experimentally unravelled after 60 years: First definitive experimental evidence of two-dimensional melting of hard spheres April 21st, 2017

Wood filter removes toxic dye from water April 21st, 2017

Rice crew revved for Nanocar Race: Nanocar creator James Tour and team take on international competition with single-molecule marvel April 20th, 2017

Better living through pressure: Functional nanomaterials made easy April 19th, 2017

Announcements

Two-dimensional melting of hard spheres experimentally unravelled after 60 years: First definitive experimental evidence of two-dimensional melting of hard spheres April 21st, 2017

National Conference on Nanomaterials, (NCN-2017) April 21st, 2017

NanoMONITOR shares its latest developments concerning the NanoMONITOR Software and the Monitoring stations April 21st, 2017

Nanomechanics, Inc. Unveils New Product at ICMCTF Show April 25th: Nanoindentation experts will launch the new Gemini that measures the interaction of two objects that are sliding across each other – not merely making contact April 21st, 2017

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



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project