The quest for still faster, smaller, more energy-efficient, and less-prone-to-fail chips will eventually push the industry beyond current CMOS semiconductor technology. But the multi-billion-dollar question is: What comes next?
The post-CMOS debate has been gaining momentum ever since experts began talking about the physics of present semiconductor technology hitting the wall between 2020 and 2022. Experts at the IEEE Time Technology Machine in Dresden debated what comes next today, and judging by the range of possibilities that came up during the “Electronics beyond CMOS” panel, there appears to be no shortage of ideas—including making CMOS work a little longer.
Kazuhiko Matsumoto, a professor at Japan’s University of Osaka, favors carbon nanotube-based transistors and suggested improving on them by using “stochastic resonance”—adding a little noise to improve the signal.
For University of California, Berkeley’s Leon Chua it’s the memristor a device whose existence he theorized in a 1971 paper. Interest in the concept has soared ever since a team of HP researchers succeeded in developing a memristor based on a thin film of titanium dioxide in 2008.
Chua says memristors were “more than memory,” referring to them as the “building blocks of brain-like machines.” Calling the component his greatest achievement in an interview with IEEE Spectrum, the IEEE Fellow expects the technology to play a play a huge roll in 2020 and beyond. “It could eventually replace flash” memory, he says.
Nanowires, nanotubes, and graphene also came up. And 3D network-on-chip (NoC) designs will make them all work better, according to Laurent Mailer, CEO of CEA Leti (Laboratory for Electronics and Information Technology) in Grenoble, France. But 3D NoC, he warned poses “brand new challenges for designers.”. And though Mailer also sees potential for photonics, he admits developers are already “sort of beating up physics” to integrate laser sources on CMOS.
For Gerhard Fettweis, a professor at the Dresden University of Technology, the answer is “simple” – 3-D stacking—a technology already well underway.
Some words of caution, however, came from Paul Farrar, vice president at IBM. “We’re trying to manipulate atoms and fight physics,” he warns. But an equally big challenge, he adds “are the economics: Electronics and economics need to blend better together.”
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