Researchers uncover the fastest semiconductor yet

https://spectrum.ieee.org/semiconductor

by g0xA52A2A • 3 years ago

167 104 3 years ago

spectrum.ieee.org

mareko• 3 years ago

"This means processing speeds in devices based on them could reach femtoseconds, a million times as fast as the speeds achievable with current gigahertz electronics"

That seems like quite the discovery.

happytiger2• 3 years ago

“Now that we know what structural and electronic properties are needed...there is good likelihood that we will find earth-abundant alternatives to this rhenium-based material.”

Unfortunately the rarest of rare materials, but the above quote does point out that it shows us what’s possible even if it isn’t viable yet.

timthelion• 3 years ago

Rhenium is used in industry already in metal aloys. It costs around $10000 per Kg. [1] And the US produced 8 tons of it in 2020 [2]. A modern cpu weighs 60g. If we were to make CPUs out of pure Rhenium we could make 133 000 a year at a cost of just $600 each for raw materials. If these things are really a million times faster than the current best in breed silicon ones they will have no trouble competing commercially. $600/ one million is not very much money at all and 133000 times one million is a LOT of compute. Furthermore, the CPUs will not be pure Rhinium.

[1] https://en.m.wikipedia.org/wiki/Rhenium

[2] https://www.statista.com/statistics/1312513/rhenium-producti...

Almondsetat• 3 years ago

The rarest or rare material can still be used in extremely specialized applications though

Simran-B• 3 years ago

They also seem to say that it cannot be used directly for improving CPUs as they are designed today:

“[…] they are not necessarily compatible with current hardware used in the semiconductor industry,” […] the applications for these semiconductors “would likely be different than those for traditional semiconductors.”

quietpain• 3 years ago

   processing speeds in devices based on them could reach femtoseconds

That would also mean switching times that allow rectifying infrared light. I.e. capturing light energy with um-sized antennas instead of bandgap traps.

tester756• 3 years ago

Materials like that aren't new, but at this very moment they aren't viable (insane cost, short life-span, etc)

tomalaci• 3 years ago

I remember when people were super excited for graphene and nanotubes in semiconductors. What happened to that? Seems like a lot of things stop dead in its tracks when it comes to mass manufacturing.

WJW3• 3 years ago

Mass manufacturing is really hard, it's not really a surprise that many things that we can do on lab scale can't be made to work (in an economical fashion) at mass production scale.

adhesive_wombat2• 3 years ago

We're incredibly lucky that copper and silicon are so (relatively) easy to work with.

Imagine if even basic electrical systems needed wires made of rhodium and semiconductors only worked at cryogenic temperatures. We'd never have gotten over the "technological activation energy" in the 1800s.

da_chicken2• 3 years ago

It's also turned out that carbon nanotubes are toxic in a similar fashion to asbestos. While a completed chip would be sealed, it does raise concerns about the safety of manufacture. Similar concerns have been raised about graphene.

DeepSeaTortoise• 3 years ago

I can't help but assume that anything being described as using graphene, carbon nanotubes, crypto, blockchain, bitcoin and - to some degree - AI is a scam.

I feel like the only person I've heard talking about graphene and actually demonstrating any practical application is Robert Murray-Smith. This guy is like he fell down the popular science rabbit hole 20 years ago and emerged naked but for a towel screaming "Eureka".

Teever• 3 years ago

That's utterly preposterous.

I work with a company that has a couple of patents on a carbon nanotube based sensing system for hydrocarbons. This company is making and selling units every day, like this shit is real man.

These units are installed out in the field all around the world and are tied into a dashboard for customers to see if any of their projects are experiencing leaks.

I agree that the carbon nano-tech revolution that we were promised by pop-sci writers hasn't materialized but that doesn't mean that it isn't a genuinely useful substance.

formerly_proven• 3 years ago

Nanotubes perhaps not, but Si nanowires and -sheets are being used for the channel in 3nm-class processes with gate-all-around structure.

ajuc• 3 years ago

First steam turbines were made in ancient Rome. Took us almost 2000 years to commercialize them :)

navi0• 3 years ago

TIL the Romans invented the first steam engine but didn’t seem to grasp its revolutionary potential and used it mostly as a party trick:

https://en.wikipedia.org/wiki/Aeolipile?wprov=sfti1

scythe• 3 years ago

Wikipedia's history of this is very nice:

http://en.wikipedia.org/wiki/History_of_the_steam_engine#Pre...

Symmetry• 3 years ago

Normally a manufacturing process is doing well if 90% of the chips on a wafer are usable. Carbon nanotube based circuits manufacture are doing well if 90% of transistors were working. That needs to be solved before they're practical.

hinkley2• 3 years ago

Did we ever categorically prove that nanotubes aren’t the next asbestos? That’s not a small problem.

I_Am_Nous2• 3 years ago

Looking into this a bit and I discovered I have carbon nanotubes in my house already [1] and I never would have guessed. Since the nanotubes are pure carbon, I'm not sure it would cause a similar immune response to asbestos, but the "black lung" issue is still likely a risk. Lungs don't like powders in general.

1.https://en.wikipedia.org/wiki/Nano_tape

seiferteric• 3 years ago

Well it depends, if you plan on grinding your semiconductors into dust and inhaling them, then yes its a problem.

phkahler2• 3 years ago

> Did we ever categorically prove that nanotubes aren’t the next asbestos?

I'm pretty sure we know they are the next asbestos. So we won't do things with them that tend to produce a bunch of dust for people to inhale.

itsthecourier• 3 years ago

Yes, it is expensive if you want millions of chips, but imagine those militar and trading operations who would be willing to pay for that speedup as an edge, hope they manufacture something soon. I just wonder how resusable is stuff like EUV when you change the semiconductor material...

kragen• 3 years ago

there are lots of ridiculously expensive materials that are economic to make microelectronics

you're probably reading this on a device that uses motherfucking hafnia for its dram dielectric

i mean admittedly hafnium is still a thousand times as abundant as rhenium

xeonmc• 3 years ago

Could this mechanism possibly be related to the Boson Peak anomaly in disordered materials? Potentially extra acoustic excitation mode caused by interactions of transient large-cluster vibrations.

dstuessy• 3 years ago

Any thoughts on how manganese and technetium seem to share similar properties to Rhenium? https://en.wikipedia.org/wiki/Rhenium

adrian_b6• 3 years ago

Technetium has very similar properties with rhenium, but as its name says it must be made artificially, because due to its low lifetime all that has existed when the Solar System has been formed has disintegrated a long time ago.

Manganese has significantly different properties (due to smaller atomic size and greater electronegativity), so just substituting it in the same chemical formula would not create the same crystal structure and any properties would be different.

Nevertheless, it is likely that other substances with similar properties will be found, but it remains to be seen if any of them are stable enough and cheap enough to be used in practical devices.

dist-epoch• 3 years ago

One major problem that Re6Se8Cl2 faces is that rhenium is one of the rarest elements on Earth. This makes Re6Se8Cl2 very expensive and unlikely to ever make its way into a commercial product.

Something doesn't add up.

Rhenium price seems to be $2k/kg. Gold price is $62k/kg. Silver price is $0.8k/kg. So Rhenium is about 3 times as expensive as silver and 30 times cheaper than gold.

lstodd• 3 years ago

I guess it's because there isn't much demand. If this takes off, prices will too.

brudgers• 3 years ago

My understanding (from binge watching Asianometry) is that the rare earth metals are not mined directly.

Instead they are extracted from ores in the tailings of large scale mining operations like coal or copper and refined by specialty processors.

It is not commercially viable to mine the rare earth elements on their own. Because the price is only $2k/kg, it makes more sense to build a business around all the coal (or whatever) that has to be moved to get a kg of a rare earth.

Because you still have to move all that dirt.

Basically, the price reflects only the costs of refining, marketing, and distribution. Extraction is sunk cost.

runeks8• 3 years ago

Rhenium price seems to be $2k/kg

Based on what?

onetimeuse923045• 3 years ago

One major problem that Re6Se8Cl2 faces is that rhenium is one of the rarest elements on Earth. This makes Re6Se8Cl2 very expensive and unlikely to ever make its way into a commercial product.

I call BS. It is rare, true. But it is found in reasonable concentrations in some minerals (alongside molybdenum) that are already being mined and we just need to learn to extract rhenium out of it. For high perf semiconductors you only need microscopic amounts of it anyway.

As to costs, majority of the costs are not in substrates anyway, however costly they are. The costs are in IP and in processing. I suspect even if silicon was as expensive as gold it would not meaningfully change the cost of current high-end CPUs that go into our phones.

(edited, I mistakenly wrote ruthenium where I meant rhenium)

foobarian3• 3 years ago

Ruthenium is a bit different than Rhenium. But either way you can get it online. https://www.rwmmint.com/products/rhenium-metal

onetimeuse923045• 3 years ago

I meant rhenium. Don't know why I wrote ruthenium, that is obviously a mistake. Thanks for pointing it out.

xwdv• 3 years ago

Why would someone buy this? What can you do with a Rhenium ingot?

adrian_b6• 3 years ago

Its concentration in minerals is not reasonable, but extremely small.

The yearly production per human is a barely visible grain with a volume of about a quarter of a cubic millimeter. If each human would want to have a ring of rhenium, that would need all the global production accumulated during one thousand years.

All of it is heavily contended for various applications like gas turbine blades, so the price is in the same range as for platinum-group elements, which are in fact much more abundant.

If the semiconductor layers would have thicknesses in the tens of nanometer range, i.e. they would be deposited on some crystallographically compatible substrate, then such a semiconductor might be usable for expensive devices.

Nevertheless, developing a deposition method that can recycle all the non-deposited rhenium may be not easy. The deposition methods normally used frequently deposit far more substance on the equipment walls than on the semiconductor wafer. When depositing pure inert metals like gold or platinum, there are relatively easy methods to recover them, e.g. by dissolving in acid everything else. Such a complex substance containing rhenium might be obtained from a chemical reaction during the deposition, but it may be difficult to find precursors that are also easy to recycle.

runeks8• 3 years ago

All of it is heavily contended for various applications like gas turbine blades […]

Then why does it only cost $1 per gram?

[1] https://pubs.usgs.gov/periodicals/mcs2021/mcs2021-rhenium.pd...

josaka• 3 years ago

My intuition matches yours. It's abundant enough to find its way into alloys for jet engine blades at single digit percentages: https://www.thenakedscientists.com/articles/science-features... And if used in chips, you don't need to make the full substrate with this material, just a few hundred nanometers at the top, in the active area.

onetimeuse923045• 3 years ago

Exactly my point, you said it better than I did.

People don't have understanding of what expensive is. Even at hundreds or thousands of dollars per gram it could be pretty much irrelevant to the end result cost if you only need a layer that is couple nanometers in width.

bob1029• 3 years ago

The cost of the raw materials is a rounding error compared to all other aspects of semiconductor manufacturing.

The entire industry is a game of "value-add". The blank silicon wafers start out with effectively zero (or negative) value. The raw materials are worthless to the business. Only once validated features (process layers) begin to accumulate do those raw materials begin to inherit some sense of value.

lost_tourist• 3 years ago

Are you discounting the cost of development of technology to support the new semiconductor material? that along with it's rarity is what I suspect they're talking about.

bell-cot• 3 years ago

A slightly important sentence, if you're caught up on the "...using Unobtainium" issue:

Although the new material is made using one of the rarest elements on Earth, the researchers suggest counterparts made from more abundant materials may be discovered that operate comparably fast.

Researchers uncover the fastest semiconductor yet

Related Stories