Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Silicon with afterburners: Process developed at Rice could be boon to electronics manufacturer

27.07.2009
Scientists at Rice University and North Carolina State University have found a method of attaching molecules to semiconducting silicon that may help manufacturers reach beyond the current limits of Moore's Law as they make microprocessors both smaller and more powerful.

Their findings are published this month by the Journal of the American Chemical Society.

Moore's Law, suggested by Intel co-founder Gordon Moore in 1965, said the number of transistors that can be placed on an integrated circuit doubles about every two years. But even Moore has said the law cannot be sustained indefinitely.

The challenge is to get past the limits of doping, a process that has been essential to creating the silicon substrate that is at the heart of all modern integrated circuits, said James Tour, Rice's Chao Professor of Chemistry and professor of mechanical engineering and materials science and of computer science.

Doping introduces impurities into pure crystalline silicon as a way of tuning microscopic circuits to a particular need, and it's been effective so far even in concentrations as small as one atom of boron, arsenic or phosphorus per 100 million of silicon.

But as manufacturers pack more transistors onto integrated circuits by making the circuits ever smaller, doping gets problematic.

"When silicon gets really small, down to the nanoscale, you get structures that essentially have very little volume," Tour said. "You have to put dopant atoms in silicon for it to work as a semiconductor, but now, devices are so small you get inhomogeneities. You may have a few more dopant atoms in this device than in that one, so the irregularities between them become profound."

Manufacturers who put billions of devices on a single chip need them all to work the same way, but that becomes more difficult with the size of a state-of-the-art circuit at 45 nanometers wide -- a human hair is about 100,000 nanometers wide -- and smaller ones on the way.

The paper suggests that monolayer molecular grafting -- basically, attaching molecules to the surface of the silicon rather than mixing them in -- essentially serves the same function as doping, but works better at the nanometer scale. "We call it silicon with afterburners," Tour said. "We're putting an even layer of molecules on the surface. These are not doping in the same way traditional dopants do, but they're effectively doing the same thing."

Tour said years of research into molecular computing with an eye toward replacing silicon has yielded little fruit. "It's hard to compete with something that has trillions of dollars and millions of person-years invested into it. So we decided it would be good to complement silicon, rather than try to supplant it."

He anticipates wide industry interest in the process, in which carbon molecules could be bonded with silicon either through a chemical bath or evaporation. "This is a nice entry point for molecules into the silicon industry. We can go to a manufacturer and say, 'Let us make your fabrication line work for you longer. Let us complement what you have.'

"This gives the Intels and the Microns and the Samsungs of the world another tool to try, and I guarantee you they'll be trying this."

The paper, "Controllable Molecular Modulation of Conductivity in Silicon-Based Devices," was authored by Tour and his team of graduate student David Corley and former postdoctoral students Tao He, Meng Lu and Jianli He, along with Neil Halen Di Spigna, David Nackashi and Paul Franzon of North Carolina State University.

The paper is online at http://pubs.acs.org/doi/abs/10.1021/ja9002537.

Caption for illustration: Attaching molecules to semiconducting silicon affects the threshold voltage, or gate voltage, required to create a conductive path between the source and drain electrodes (blue) and turn the device on. The molecules influence the amount of charge carriers available within the device layer (red).

David Ruth | EurekAlert!
Further information:
http://www.rice.edu

More articles from Power and Electrical Engineering:

nachricht Scientists create biodegradable, paper-based biobatteries
08.08.2018 | Binghamton University

nachricht Ricocheting radio waves monitor the tiniest movements in a room
07.08.2018 | Duke University

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

Staying in Shape

16.08.2018 | Life Sciences

Diving robots find Antarctic seas exhale surprising amounts of carbon dioxide in winter

16.08.2018 | Earth Sciences

Protein droplets keep neurons at the ready and immune system in balance

16.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>