Atomically thin, strong graphene-based integrated circuits
August 31, 2012
Schematic illustration of single-atom-thick films with patterned regions of conducting graphene (gray) and insulating boron nitride (purple-blue) (credit: Jiwoong Park)
To go beyond Moore’s law and reduce the size of integrated circuits down to single-atom thickness, researchers led by Jiwoong Park, assistant professor of chemistry and chemical biology at Cornell, have invented a way to pattern single-atom films of graphene and insulating boron nitride without the use of a silicon substrate.
The new “patterned regrowth” technique could lead to substrate-free circuits so thin that they could float on water or through air, but with tensile strength and top-notch electrical performance.
The technique combines graphene (single-atom-thick sheets of repeating carbon atoms) and hexagonal boron nitride, thin sheets of repeating boron and nitrogen atoms.
Patterned regrowth
Patterned regrowth, which harnesses the same basic photolithography technology used in silicon wafer processing, allows graphene and boron nitride to grow in perfectly flat, structurally smooth films — no creases or bumps. If combined with a semiconductor material, they could lead to the first atomically thin integrated circuit.
Patterned regrowth is a bit like stenciling, Park said. He and colleagues first grew graphene on copper and used photolithography to expose graphene on selected areas, depending on the desired pattern. They filled that exposed copper surface with boron nitride, the insulator, which grows on copper and “fills the gaps in very nicely.”
“In the end, it forms a very nice cloth you just peel off,” Park said.
“Devices made using this approach are likely to remain mechanically flexible and optically transparent, allowing transfer to arbitrary substrates for flexible, transparent electronics,” the researchers said in the Nature article.
The research team, which includes David A. Muller, professor of applied and engineering physics, is working to determine what material would best work with graphene-boron nitride thin films to make up the final semiconducting layer that could turn the films into actual devices.
The work was supported primarily by the Air Force Office of Scientific Research, and the National Science Foundation through the Cornell Center for Materials Research.
Comments (6)
by Spikosauropod
Solid graphene electronics. Sounds like the makings of computronium. Virtually indestructible implements that are dense with computing power.
by Starheart
So are we going to get graphene circuits after all? A few days ago there was an article here saying graphene is unlikely to be used for the purpose due to lacking a certain physical property, as quoted:
“There was a “hefty bottleneck” to making progress with graphene, he explains, because that material lacks a bandgap — the key property that makes it possible to create transistors, the basic component of logic and memory circuits. While graphene needs to be modified in exacting ways in order to create a bandgap, MoS2 just naturally comes with one. The lack of a bandgap, Wang explains, means that with a switch made of graphene, “you can turn it on, but you can’t turn it off. That means you can’t do digital logic.””
by Editor
In this design, they are using graphene as conductive materials, not semiconductors. As noted, the researchers haven’t found a compatible transistor material to use with it yet.
by Ian Clarke
I like it! Future computers could resemble cling film. Kids could plaster their school bags with them, while adults turn their bathroom mirrors and windows into… well, whatever they want. I’m sure Project Glass are watching with interest.
I wonder how long before liquid computers are a reality?
by Editor
Have you checked your faucet lately? :)
by Ian Clarke
Not a problem.
Any liquid computer attempting to gain access to my home in such a manner will have to face it’s ultimate challenge: an unplugged sink. :-)