New design developed for silicon nanowire transistors

Jul 01, 2005
New design developed for silicon nanowire transistors

In an advance for nanoscale electronics, researchers at the National Institute of Standards and Technology (NIST) have demonstrated a new design for silicon nanowire transistors that both simplifies processing and allows the devices to be switched on and off more easily.

Image: A schematic diagram of the NIST nanowire transistor.

The NIST design, described in a paper published June 29 by the journal Nanotechnology,* uses a simplified type of contact between the nanowire channel and the positive and negative electrodes of the transistor. The design allows more electrical current to flow in and out of the silicon. The researchers believe the design is the first to demonstrate a "Schottky barrier" type contact for a nanowire transistor built using a "top-down" approach. This barrier, an easily formed metal contact that electrons can tunnel through, requires much less doping with impurities than do conventional ohmic contacts, thereby simplifying processing requirements. Schottky contacts also offer more resistance and restrict electrical flow to one direction when the transistor is off.

In the NIST transistor design, the 60-nanometer-wide channels exhibit a much greater difference in current between the on and off states than is true for larger reference channels up to 5 micrometers wide. This suggests that when a channel is scaled down to the nano regime, the ultra-narrow proportions significantly reduce the current leakage associated with defects in silicon. As a result, the transistors are less sensitive to electronic "noise" in the channel and can be turned on and off more effectively, according to the paper's lead author, Sang-Mo Koo, a NIST guest researcher.

Silicon nanowire devices have received considerable attention recently for possible use in integrated nanoscale electronics as well as for studying fundamental properties of structures and devices with very small dimensions. The NIST work overcomes some key difficulties in making reliable devices or test structures at nanoscale dimensions. The results also suggest that nanowire transistors made with conventional lithographic fabrication methods can improve performance in nanoscale electronics, while allowing industry to retain its existing silicon technology infrastructure.

*S.M. Koo, M.D. Edelstein, Q.Li, C.A. Richter and E.M. Vogel. 2005. Silicon nanowires as enhancement-mode Schottky barrier field-effect transistors. Nanotechnology 16. Posted online June 29.

Source: NIST

Explore further: Chemical vapor deposition used to grow atomic layer materials on top of each other

add to favorites email to friend print save as pdf

Related Stories

Simulating the sun for photovoltaic research

Aug 31, 2012

PML researchers have devised a novel source of portable sunlight that may fill an urgent need in renewable energy research – namely, light sources that generate a near-perfect solar spectrum to be used ...

Bright future for gaN nanowires

Nov 29, 2011

The gallium nitride nanowires grown by PML scientists may only be a few tenths of a micrometer in diameter, but they promise a very wide range of applications, from new light-emitting diodes and diode lasers ...

Recommended for you

Physicists create new nanoparticle for cancer therapy

8 hours ago

A University of Texas at Arlington physicist working to create a luminescent nanoparticle to use in security-related radiation detection may have instead happened upon an advance in photodynamic cancer therapy.

User comments : 0

More news stories

Down's chromosome cause genome-wide disruption

The extra copy of Chromosome 21 that causes Down's syndrome throws a spanner into the workings of all the other chromosomes as well, said a study published Wednesday that surprised its authors.

Researchers see hospitalization records as additional tool

Comparing hospitalization records with data reported to local boards of health presents a more accurate way to monitor how well communities track disease outbreaks, according to a paper published April 16 in the journal PLOS ON ...

Ebola virus in Africa outbreak is a new strain

The Ebola virus that has killed scores of people in Guinea this year is a new strain—evidence that the disease did not spread there from outbreaks in some other African nations, scientists report.