Featured Research

from universities, journals, and other organizations

Microelectronics: Two at a time

Date:
June 21, 2012
Source:
The Agency for Science, Technology and Research (A*STAR)
Summary:
A new design reduces the areal footprint of nanowire transistors by a factor of two. Scientists have now integrated two transistors onto a single vertical silicon nanowire, pushing the areal density limit of nanowire transistors even further.

A new design reduces the areal footprint of nanowire transistors by a factor of two. Xiang Li at the A*STAR Institute of Microelectronics and co-workers have now integrated two transistors onto a single vertical silicon nanowire, pushing the areal density limit of nanowire transistors even further.

Semiconductor chip makers first began the production of three-dimensional (3D) transistors in 2011. Engineers can pack more 3D transistors onto a single chip because they are much more compact than traditional transistors.

For future generations of semiconductor chips, however, there is a need to shrink these 3D transistors further and the use of vertical nanowires in the transistor design is one of the promising approaches. Moreover, the area taken up by a nanowire-based transistor is typically half that of a planar transistor -- or even less if considering more complicated components, like inverters. Xiang Li at the A*STAR Institute of Microelectronics and co-workers have now integrated two transistors onto a single vertical silicon nanowire, pushing the areal density limit of nanowire transistors even further.

The researchers used wrap-around gates, or 'gate-all-around' gates, in the making of their device. These gates consist of a vertical cylinder, at the center of which lies the nanowire. They are much better at controlling the transistor current than traditional planar gates. Li and co-workers decreased the area required for a gate-all-around nanowire transistor by a factor of two by constructing two transistors out of a single vertical nanowire. Their design involves two wrap-around gates, one above the other, separated by a thin dielectric layer to isolate them electrically (see image). Unlike other independent double-gate transistor designs, such as those employing a vertical fin-like channel, changing the gate voltage applied to one transistor does not change the threshold (or turn-on) voltage of the other. This means that either of the gates can modulate the nanowire current independently.

As a result, Li and co-workers were able to construct a simple logic device using just one nanowire. For a nanowire doped with negative carriers, current was able to flow when both gate voltages were high, but current stopped when either gate voltage was low. This device therefore functioned as an 'AND' digital gate, but used only half the area it otherwise would require. The stacked gate arrangement may also be useful for enabling an emerging type of transistor, called a tunnel field effect transistor (TFET). Because TFETs rely on the tunneling of electrons across a barrier rather than the thermal activation of electrons, they turn on very quickly and consume very little power. Li says the tunnel junction required for a TFET could be formed between the two gates of the dual-gate nanowire geometry, allowing a particularly compact implementation. The dual-gate design could also be used for other technologies, such as non-volatile memory.


Story Source:

The above story is based on materials provided by The Agency for Science, Technology and Research (A*STAR). Note: Materials may be edited for content and length.


Journal Reference:

  1. Li, X. et al. Vertically stacked and independently controlled twin-gate MOSFETs on a single Si nanowire. IEEE Electron Device Letters, 32, 1492-1494 (2011) DOI: 10.1109/LED.2011.2165693

Cite This Page:

The Agency for Science, Technology and Research (A*STAR). "Microelectronics: Two at a time." ScienceDaily. ScienceDaily, 21 June 2012. <www.sciencedaily.com/releases/2012/06/120621101814.htm>.
The Agency for Science, Technology and Research (A*STAR). (2012, June 21). Microelectronics: Two at a time. ScienceDaily. Retrieved April 21, 2014 from www.sciencedaily.com/releases/2012/06/120621101814.htm
The Agency for Science, Technology and Research (A*STAR). "Microelectronics: Two at a time." ScienceDaily. www.sciencedaily.com/releases/2012/06/120621101814.htm (accessed April 21, 2014).

Share This



More Matter & Energy News

Monday, April 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Why Did Nike Fire Most Of Its Nike FuelBand Team?

Why Did Nike Fire Most Of Its Nike FuelBand Team?

Newsy (Apr. 19, 2014) Nike fired most of its Digital Sport hardware team, the group behind Nike's FuelBand device. Could Apple or an overcrowded market be behind layoffs? Video provided by Newsy
Powered by NewsLook.com
Small Reactors Could Be Future of Nuclear Energy

Small Reactors Could Be Future of Nuclear Energy

AP (Apr. 17, 2014) After the Fukushima nuclear disaster, the industry fell under intense scrutiny. Now, small underground nuclear power plants are being considered as the possible future of the nuclear energy. (April 17) Video provided by AP
Powered by NewsLook.com
Horseless Carriage Introduced at NY Auto Show

Horseless Carriage Introduced at NY Auto Show

AP (Apr. 17, 2014) An electric car that proponents hope will replace horse-drawn carriages in New York City has also been revealed at the auto show. (Apr. 17) Video provided by AP
Powered by NewsLook.com
Honda's New ASIMO Robot, More Human-Like Than Ever

Honda's New ASIMO Robot, More Human-Like Than Ever

AFP (Apr. 17, 2014) It walks and runs, even up and down stairs. It can open a bottle and serve a drink, and politely tries to shake hands with a stranger. Meet the latest ASIMO, Honda's humanoid robot. Duration: 00:54 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins