Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

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

A first glimpse inside a macroscopic quantum state March 28th, 2015

DFG to Establish One Clinical Research Unit and Five Research Units: New Projects to Investigate Complications in Pregnancy, Particle Physics, Nanoparticles, Implants and Transport Planning / Approximately 13 Million Euros in Funding for an Initial Three-Year Period March 28th, 2015

Chemists make new silicon-based nanomaterials March 27th, 2015

UT Dallas engineers twist nanofibers to create structures tougher than bulletproof vests March 27th, 2015

Chip Technology

State-of-the-art online system unveiled to pinpoint metrology software accuracy March 27th, 2015

SUNY POLY CNSE to Host First Ever Northeast Semi Supply Conference (NESCO) Conference Will Connect New and Emerging Innovators in the Northeastern US and Canada with Industry Leaders and Strategic Investors to Discuss Future Growth Opportunities in NYS March 25th, 2015

NXP and GLOBALFOUNDRIES Announce Production of 40nm Embedded Non-Volatile Memory Technology: Co-developed technology to leverage GLOBALFOUNDRIES 40nm process technology platform March 24th, 2015

Building shape inspires new material discovery March 24th, 2015

Discoveries

A first glimpse inside a macroscopic quantum state March 28th, 2015

UT Dallas engineers twist nanofibers to create structures tougher than bulletproof vests March 27th, 2015

Novel nanoparticle therapy promotes wound healing March 27th, 2015

Designer's toolkit for dynamic DNA nanomachines: Arm-waving nanorobot signals new flexibility in DNA origami March 27th, 2015

Announcements

A first glimpse inside a macroscopic quantum state March 28th, 2015

DFG to Establish One Clinical Research Unit and Five Research Units: New Projects to Investigate Complications in Pregnancy, Particle Physics, Nanoparticles, Implants and Transport Planning / Approximately 13 Million Euros in Funding for an Initial Three-Year Period March 28th, 2015

Designer's toolkit for dynamic DNA nanomachines: Arm-waving nanorobot signals new flexibility in DNA origami March 27th, 2015

Using magnetic fields to understand high-temperature superconductivity: Los Alamos explores experimental path to potential 'next theory of superconductivity' March 27th, 2015

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







© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE