
Engineered Band Gap Pushes Graphene Closer to Displacing Silicon - rbanffy
https://spectrum.ieee.org/nanoclast/semiconductors/nanotechnology/engineered-band-gap-pushes-graphene-closer-to-displacing-silicon
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Simulacra
I wonder what kind of pressure we’re talking about to achieve that EV gap.

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inteleng
~2.3 GPa, the max mentioned in the paper, equates to around 20k atmospheres of
pressure or around 300k psi.

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Simulacra
That seems like an enormous amount of pressure. Can you put that into
perspective, please?

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thechao
Imagine 80 full sized SUVs stacked on top of each other, balanced on a 1”
square metal rod.

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ncmncm
I don't understand why they insist on fooling with carbon, when phosphorus
forms nice sheets like graphene that are naturally semiconconducting.

It probably has a lot to do with appealing to the prejudices of grant
committees.

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alxlaz
Black phosphorus sheets are great but they are pretty hard to fabricate and
they degrade very quickly when they come in contact with air (in a matter of
hours). There have been various attempts to solve this, some of them
successful (as far as we can tell from lab experiments, at least), but all
solutions are in pretty early stages, and most of them seem pretty difficult
to implement on an industrial scale. Basically, exposing the damn thing to
anything but inert gases for more than a couple of hours destroys it. That's
not too feasible today.

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wbl
Can the computer in high pressure helium: better thermal conductivity then
air. Or space applications.

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dEnigma
The topic was replacing silicon. I'm sure there are niche applications for it,
but having to seal everything helium-tight won't work for all use cases that
are served by silicon chips.

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jcims
The silicon is rarely exposed to air though. This is just a manufacturing
issue, isnt it?

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raverbashing
I suppose so, but it's easier to have your factory with ultra-clean air than
have it with inert gases.

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dogma1138
With submersion litography and the silicon wafers being in inert gas chambers
for annealing to prevent oxidation faults I’m not sure that’s actually the
case.

You usually don’t want to expose anything to oxygen especially something that
is only a few nanometers thick so even if the base silicon does not oxidize
(which afaik it does) once you begin the doping process not to mention laying
down the metal layers oxygen is a big no no, the oxide layer that form on say
copper coins is thicker than the copper layers in most ICs so I really don’t
see oxygen as being viable medium during manufacturing.

Based on this it seems that when Oxygen is used it’s used as a purge gas
[https://www.globalspec.com/learnmore/materials_chemicals_adh...](https://www.globalspec.com/learnmore/materials_chemicals_adhesives/industrial_specialty_gases/electronic_semiconductor_gases)

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MeteorMarc
Duh, the article speaks of Van der Waal forces instead of Van der Waals
forces.

