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New Carbon Nanotube Chip Outperforms Silicon Semiconductors (nanotechweb.org)
"Researchers at the University of Wisconsin-Madison are the first to have fabricated carbon nanotube transistors (CNTs) that outperform the current-density of conventional semiconductors like silicon and gallium arsenide," reports NanotechWeb.
Slashdot reader wasteoid
shares the site's interview with one of the researchers:
"When the transistors are turned on to the conductive state (meaning that current is able to pass through the CNT channel) the amount of current traveling through each CNT in the array approaches the fundamental quantum limit," he tells nanotechweb.org.
"Since the CNTs conduct in parallel, and the packing density and conductance per tube are very high, the overall current density is very high too -- at nearly twice that of silicon's. The result is that these CNT array FETs have a conductance that is seven times higher than any previous reported CNT array field-effect transistor."
The research was funded in part by the U.S. Army and Air Force, as well as the National Science Foundation. "The implication here is that by replacing silicon with a CNT channel, it should be possible for us to make either a higher performing device or one that works at lower power."
In other news, Fujitsu announced this week that it's joining an effort to release a 256-megabyte 55-nanometer carbon nanotube-based NRAM by 2018.
"Since the CNTs conduct in parallel, and the packing density and conductance per tube are very high, the overall current density is very high too -- at nearly twice that of silicon's. The result is that these CNT array FETs have a conductance that is seven times higher than any previous reported CNT array field-effect transistor."
The research was funded in part by the U.S. Army and Air Force, as well as the National Science Foundation. "The implication here is that by replacing silicon with a CNT channel, it should be possible for us to make either a higher performing device or one that works at lower power."
In other news, Fujitsu announced this week that it's joining an effort to release a 256-megabyte 55-nanometer carbon nanotube-based NRAM by 2018.
Hooray? There have been breathless articles about how diamond or CNT or whatever stomps silicon flat for 30 years now. The problem is that silicon is a moving target - it keeps being improved. If CNT or diamond is fundamentally better than the best possible silicon, which it probably is, the only way it can "catch up" is if silicon is improved to it's practical limits. That might be just a few years away - there's talk of the next few die shrinks being the last ones for silicon before physics don't allow any further improvement for 2d silicon wafers. (and 3d has the fundamental problem of trapping heat and much more difficult manufacturing)
Still, this is cool. I wonder if large scale power switch transistors can be a new future use for CNT tech? If they have better current flow and less "on" resistance, superior to silicon, that would be great.
Good. Maybe high-power motor controllers will become cheaper.
Don't stop where the ink does.
Have they found a practical way to mass produce single walled carbon nanotubes of arbitrary diameter and length yet?
I ask, because that is sadly a requirement for mass manufacture of quality ICs built using carbon semiconductor.
If they can pull that off cheaply and reliably, that enables carbon to really hit home as an industrial material, and things would get interesting.
Hand assembling an IC out of cherry picked parts in a cleanroom is not the same as the above. Yes, it lets you see that such chips have immense potential, but without a viable path to mass manufacture, the unit costs will be astoundingly prohibitive. Only the USA's DoD would be able to afford them. I really can't get behind such a nasty barrier in tech as that. The NSA has scary enough toys as is. Having access to ICs that they can drive many times harder than silicon, while the rest of us are left to pound sand due to the price, is not something I want to see.