Integrated circuit stamp to be issued this week The U.S. Postal Service is scheduled to issue the Integrated Circuit Stamp this week (Sept. 17, 2 PM) at the University of Texas, Dallas (Eugene McDermott Library). At the ceremony, the Postal Service and the university will recognize Jack Kilby, inventor of the integrated circuit.
September 13, 1999
Yet researchers who study nanoscale electronics usually wire up the nanometer-sized circuit components—carbon nanotubes, for example—using electrical contacts that are enormous compared with the nanotubes. They accept the size disparity because no one has developed a viable way to avoid it. Until now, that is. Scientists at Harvard University have devised a method for making electrical contacts to nanometer-sized semiconductor circuit elements using metallic wires of the same dimensions as the semiconductor. The technique may lead to new strategies for integrating nanoscale components in electronic circuits and new ways of studying electron transport on the nanometer scale.
by Mitch Jacoby | July 05, 2004
NANOWIRES AND NANOTUBES Harvard chemists use surface patterning methods and four semiconducting nanowires (top) to connect the elements of a NOR logic gate (as indicated by the circuit symbol). Delft researchers fabricate transistors (bottom) using carbon nanotubes and metal electrodes. Physical constraints make it unlikely that circuits based on lithographically patterned semiconductor chips can be made much smaller than they are presently.
by MITCH JACOBY | November 12, 2001
Azzarelli, and coworkers adapted near-field communication (NFC) tags—simple integrated circuits on plastic substrates—as chemical sensors for selective gas detection (Proc. Natl. Acad. Sci. USA 2014, DOI: 10.1073/pnas.1415403111). The ultra-low-power requirements of their carbon-nanotube-based sensors enable the NFC tags, which are battery-free, to communicate with and be powered by cell phones via radio-frequency pulses. To make the sensors, the researchers punch a hole in the conductive aluminum of an NFC tag’s circuit, making the tag unreadable. They then recomplete the circuit with carbon-nanotube-based materials designed to respond to specific gas molecules. In the presence of these molecules, the nanotubes change the resistance of the circuit and the resonant frequency of the tag, thus affecting the tag’s ability to communicate with cell phones.
by Celia Henry Arnaud | December 11, 2014
—‘Hot’ dots for quantum computing “Silicon qubits that operate at less frigid temperatures promise more powerful computers” Two separate teams of researchers have shown that they can build quantum logic circuits using silicon quantum dots that operate at a significantly higher temperature than existing ones, potentially opening the door to less expensive, more complex machines.
by Neil Savage | April 24, 2020
—Semiconductors From Liquids “Method enables fabrication of circuit components starting from a liquid silane” A novel semiconductor-processing technique based on a liquid precursor to solid silicon may one day replace traditional vapor-deposition methods for fabricating microelectronic devices. The procedure, developed by researchers in Japan, may enable the use of low-cost ink-jet printing methods to manufacture large-area displays and other advanced electronic devices.
by Mitch Jacoby | April 10, 2006
—Zhenan Bao makes stretchable electronics for artificial skin “Stanford professor envisions semiconducting polymers with integrated sensors to coat robots or prostheses” Zhenan Bao of Stanford University is the first recipient of the ACS Central Science Disruptors and Innovators Prize, which highlights a paradigm-shifting scientific breakthrough of broad relevance (ACS also publishes C&EN).
by Neil Savage, special to C&EN | August 18, 2020
Yet researchers who study nanoscale electronics usually wire up the nanometer-sized circuit componentscarbon nanotubes, for exampleusing electrical contacts that are enormous compared with the nanotubes. They accept the size disparity because no one has developed a viable way to avoid it. Until now, that is. Scientists at Harvard University have devised a method for making electrical contacts to nanometer-sized semiconductor circuit elements using metallic wires of the same dimensions as the semiconductor. The technique may lead to new strategies for integrating nanoscale components in electronic circuits and new ways of studying electron transport on the nanometer scale.
by MITCH JACOBY | July 05, 2004
At the time it was introduced, circuit lines were 220 nm wide. But today, as circuitry has shrunk to widths of 22 nm and below, new problems are emerging for copper. A big one, explains David Thompson, Applied Materials’ technology director for process chemistries, is electromigration. Running electric current—electrons—through the ultrathin wires can dislocate copper ions, creating voids in the circuit and opening the door to chip failure.
by Michael McCoy | August 25, 2014