Gentler processing may yield better molecular devices

January 26, 2005
Gentler processing may yield better molecular devices

A simple, chemical way to attach electrical contacts to molecular-scale electronic components has been developed by researchers at the National Institute of Standards and Technology (NIST). The recently patented method attaches a layer of copper on the ends of delicate molecular components to avoid damage to the components that commonly occurs with conventional techniques.

Image: Copper contact deposition on organic electronic molecules using the NIST patented process is highly specific, an important feature for building dense arrays of devices. Shown here is a cross-hatched pattern of copper deposits on 10-micrometer-wide, single-layer strips of molecules that have been bound to a gold substrate with microcontact printing.

Molecular electronics--designing carbon-based molecules to act as wires, diodes, transistors and other microelectronic devices--is one of the most dynamic frontiers in nanotechnology. An area equal to the cross-section of a typical human hair might hold about a thousand semiconductor transistors at the current state of art, but up to 13 million molecular transistors.

A key challenge in molecular electronics is making electrical contacts to the fragile molecules, chemical chains that are easily damaged. Currently, this is most often done by vaporizing a metal onto the molecules that stand like blades of grass on a metal substrate. The vaporized metal atoms are supposed to settle on the tops of the molecules but they also often eat away at the delicate structures, or fall through gaps in the "turf" and short out the device. Yields of working devices are typically only a few percent.

NIST researchers designed a technique in which the molecules are synthesized with an additional chemical group attached to the top of the molecule. The chip is immersed in a solution including copper ions, which preferentially bind to the added group, forming a strong, chemically bonded contact that also protects the underlying molecule during further metallic vapor deposition steps. Tests at NIST have demonstrated that the technique works well on surfaces patterned with microcontact printing, producing clean, sharply defined edges, important for the fabrication of practical devices.

Patent: See U.S. patent, no. 6,828,581 available here: patapsco.nist.gov/TS/220/sharedpatent/pdf/6828581.pdf

Source: NIST

Explore further: The incredible shrinking ESR machine

Related Stories

The incredible shrinking ESR machine

July 15, 2015

Researchers at the National Institute of Standards and Technology (NIST) have come up with a way to shrink a research instrument generally associated with large machines that make bulk measurements of samples down to a literally ...

Liquids and glasses relax, too: But not like you thought

January 15, 2015

A new insight into the fundamental mechanics of the movement of molecules recently published by researchers at the National Institute of Standards and Technology (NIST) offers a surprising view of what happens when you pour ...

Recommended for you

Clues from ancient Maya reveal lasting impact on environment

September 3, 2015

Evidence from the tropical lowlands of Central America reveals how Maya activity more than 2,000 years ago not only contributed to the decline of their environment but continues to influence today's environmental conditions, ...

How to curb emissions? Put a price on carbon

September 3, 2015

Literally putting a price on carbon pollution and other greenhouse gasses is the best approach for nurturing the rapid growth of renewable energy and reducing emissions.

X-rays reveal fossil secrets

September 3, 2015

A sophisticated imaging technique has allowed scientists to virtually peer inside a 10-million-year-old sea urchin, uncovering a treasure trove of hidden fossils.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.