BALTIMORE To hear leading experts on emerging chip technologies tell it, nanoelectromechanical systems, or NEMS, the smaller cousin of mainstream MEMS sensor technology, are underappreciated and could be the next big thing in semiconductor technology.
|Sematech's Raj Jammy|
One reason, said Raj Jammy, vice president of emerging technologies at the Sematech manufacturing consortium (Austin, Texas), is that reliable MEMS technology has opened up a huge new market for various sensors in iPhones and all the other iStuff made by Apple and its rivals. But MEMS are application specific, Jammy noted during an interview at the International Electron Devices Meeting (IEDM) here this week. "NEMS gives you a suite" of potential applications.
NEMS technology has been described as the fusion of MEMS and nanotechnology. "If the system has a key enabling mechanical component or structure less than 1 micrometer in size and can be integrated with other dissimilar components—it's NEMS," wrote Dennis Polla, who manages NEMS research at the Defense Advanced Research Projects Agency (Darpa). Polla said the agency considers NEMS nothing less than "the next revolution in miniaturization."
Darpa is looking for ways to use NEMS technology to integrate sensors, actuators, electronics, photonics and even fluidics on a single device.
From a production standpoint, however, Jammy said, "Nobody is really investigating the NEMS side," adding, "How do we integrate [NEMS] into a CMOS flow?"
A cursory review of technical papers delivered at this year's IEDM reveals at least nine research teams addressing various aspects NEMS technology and related areas like NEMS CMOS memory and other NEMS applications. Moreover, the IEEE has been sponsoring a NEMS technical conference since 2006. The fifth annual NEMS conference is scheduled for Jan. 20-23 in Xiamen, China.
Jammy's point is that the time is ripe to begin working on ways to make new NEMS devices using existing CMOS process technology. "To harness the true potential of such devices, we are fabricating them in CMOS flows, rather than typical MEMS flows, and these devices are CMOS compatible," he said.
Like other emerging chip technologies, the potential of NEMS is largely the promise of lower power consumption. But NEMS devices also could operate at gigahertz speeds, exhibit extremely low leakage, offer compatibility with the existing CMOS manufacturing infrastructure and provide a unique set of potential applications in harsh environments where traditional silicon fails.
Jammy said that means NEMS technology could find applications far beyond touch sensors in iPhones, for example. These rugged applications include storage devices in automotive, industrial and other harsh environments along with RF and biomedical applications. Darpa is also looking to integrate NEMS devices into weapons.
At the device level, Sematech has been working with researchers at the University of California-Berkeley and Stanford University on memory devices such as NEMS "zero leakage" switches along with a hybrid switching device that would use CMOS technology for "on" and NEMS for "off" switching.
Some of the NEMS research is funded by the Darpa, which among other things is interested in understanding and exploiting the reliability of NEMS-based systems in harsh environments. Darpa's Microsystems Technology Office is overseeing the science and technology program for both NEMS and MEMS technology research, which includes funding for focus centers at universities, government laboratories and industry research organizations like Sematech.
Farther afield, NEMS research presented at IEDM covered the integration of NEMS-CMOS technology with a device called a "fin flip-flop actuated channel transistor," a NEMS application for graphene, a design for a NEMS switch based on graphene nanoribbons and a NEMS switching device insulated in liquid to reduce power consumption and improve reliability.