Novel "Two-Dimensional" Transistors Could Be the Key to Keeping Moore's Law Alive
Building "2D" monolayer transistors could help manufacturers break the nanometer barrier and continue improving silicon chips.
Researchers from the Massachusetts Institute of Technology (MIT), the University of California at Berkeley, the Taiwan Semiconductor Manufacturing Company (TSMC), and further afield have reported on a potential breakthrough for breaking through the barriers to Moore's Law: 2D transistors.
Coined by Intel co-founder Gordon Moore, Moore's Law is the observation that the number of transistors on a leading-edge microchip trend towards a doubling every 18 months. Historically, this has proven true and is by and large responsible for the incredible performance gains seen in everything from low-power microcontrollers to high-end accelerators — but as the size of the transistors and the distance between them decreases, troubling physics rear their ugly head and threaten to halt progress.
Finding a way around the limits to shrinking transistors is, then, key — and researchers say they may have found the trick. "We resolved one of the biggest problems in miniaturizing semiconductor devices," explains Dr. Pin-Chun Shen of the team's work: "The contact resistance between a metal electrode and a monolayer semiconductor material."
The secret: Bismuth, a so-called "semi-metal" element, which was swapped in for ordinary metals used connection between molybdenum disulphide "monolayer" materials — creating, in effect, a transistor close to being two dimensional.
Using this new approach, the researchers believe the channel length of a transistor could be cut from the current state of the art at 5 to 10 nanometers to sub-nanometer scales — keeping Moore's Law ticking and allowing manufacturers to once again improve performance, or reduce power draw for the same performance.
"Our reported contact resistances are a substantial improvement for two-dimensional semiconductors," the team reports, "and approach the quantum limit. This technology unveils the potential of high-performance monolayer transistors that are on par with state-of-the-art three-dimensional semiconductors, enabling further device downscaling and extending Moore’s Law."
The work has been published under closed-access terms in the journal Nature.