High-Performance Monolithic Graphene Transistors Created

MrSeb writes "Hardly a day goes by without a top-level research group announcing some kind of graphene-related breakthrough, but this one's a biggy: Researchers at the University of Erlangen-Nuremberg, Germany have created high-performance monolithic graphene transistors using a simple lithographic etching process. This could be the missing step that finally paves the way to post-silicon electronics. In theory, according to early demos from the likes of IBM and UCLA, graphene transistors should be capable of switching at speeds between 100GHz and a few terahertz. The problem is, graphene doesn't have a bandgap — it isn't a natural semiconductor, like silicon — and so it is proving very hard to build transistors out of the stuff. Until now! The researchers say that current performance "corresponds well with textbook predictions for the cutoff frequency of a metal-semiconductor field-effect transistor," but they also point out that very simple changes could increase performance 'by a factor of ~30.'"

Something missing in the explanation

[Required Snark]

I read the article (I know it's not considered good form here on Slashdot), and there seems to be a discrepancy: this is described as being a graphene transistor, but the gate uses silicon carbide as the semiconductor. So it seems like a better description would be a hybrid graphene/semiconductor transistor. Is this correct?

If it is a hybrid then what are the limitations and how is it better then current all semiconductor circuits? As far as I know (not very much) there is no reason to build silicon carbide integrated circuits, so why would anyone want to use SIC with graphene? Is this a step to something more useful?

I'm not trolling, I just want to get a better understanding.

Re:Hype ?

[Canazza]

Any increase in performance without reducing size is a step forwards.
If speed increases, for example, we'd go from 4GHz to 120GHz, which is at the low end of the scale mentioned in the summary (ie, it goes up to a few Terahertz in theory)
So we'd be at the start of a whole new clock speed race.

Re:Something missing in the explanation

[zrbyte]

Exactly the channel is SiC, while the interconnects are graphene. so in this sense it's using graphene, but it's not a transistor which uses graphene as the channel material. Previous work that has been cited in the Extremetech article is a graphene channel transistor. So there's a bit of a mix up.
It is a significant step, but this is in no way revolutionary as the summary implies. Revolutionary would be to induce a band gap in graphene, while keeping it's extremely high mobility for fast switching and using that as the channel material.

clock skew?

[martyb]

Any increase in performance without reducing size is a step forwards.If speed increases, for example, we'd go from 4GHz to 120GHz, which is at the low end of the scale mentioned in the summary (ie, it goes up to a few Terahertz in theory)So we'd be at the start of a whole new clock speed race.

That sounds great, but at those speeds the distance traveled per tick gets *much* smaller. I see a challenge in trying to propogate(sp?) a clock signal across the chip to have things work in concert with each other. I'm more a software guy than HW so I may be missing something obvious? ISTR an article here about a year or two ago about clockless logic. Would we need something like that in order to make a modern CPU out of this tech?

tl;dr How do you keep the clock from getting skewed up?