Researchers Build First Molybdenite Microchip

An anonymous reader writes "A Swiss team may have found an alternative to silicon microchips which could result in smaller, more flexible and less energy hungry processors. The Swiss team's chip does not use silicon, but molybdenite (MoS2) a dark-colored, naturally occurring mineral that is able to be used in much thinner layers (paywall)."

Comments

But

[bhcompy]

But is it as common and cheap as silicon?

Re:But

[doconnor]

I don't think the cost of the raw material is significant compared to the cost to design and manufacture computer chips.

Re:But

[betterunixthanunix]

Wikipedia says Molybdenum is the 54th most abundant element on Earth. This is less abundant than silicon, but nowhere near as rare as other commonly used elements in semiconductors; Indium is far more rare.

Re:But

[Sique]

But not as common as Silicon, which you can literally shovel in your backyard - the upper layer of the Earth crust is called Sial because of the two most abundant metals, Silicon and Aluminium. Iron comes in as a strong third.

There is a reason, why the three commerically most used metals are also the three most abundant. Molybdenum is often found in the compounds iron ore consists of, but it takes quite some energy to extract the Molybdenum from the iron ore.

Re:But

[ChrisMaple]

Molybdenum has a thermal coefficient of expansion quite close to silicon. Because of that and other reasons, it is frequently used as a thermal conductor between the silicon die and a copper or aluminum heat spreader. My point is, it's already used with semiconductor devices and using it in the semiconductor itself isn't going to greatly increase demand.

Re:But

[EdZ]

Comparing garden-variety sand to the highly purified, monocrystalline, carefully doped silicon used in chip fabs is like grabbing a lump of charcoal and claiming graphene is just lying around.

Re:But

[MagusSlurpy]

It takes less energy to get moly out of ferrous ore than it does to reduce silicon oxide to silicon. It's also a matter of availability - even though there's more silicon than molybdenum, molybdenum is often much more pure, and found in distinct deposits, and easy to mine, versus silicon being mixed in with all kinds of other crap and distributed wildly all throughout the crust. It's the same thing with rare earths - for example, indium isn't actually rare, it's just that it's EVERYWHERE in very small amounts, instead of convenient little deposits like gold, which is in the crust at about 1/500th the amount.

Re:So soon.

[MisterMidi]

You mean like Nokia does?

Re:So soon.

[jellomizer]

No no. This is an Apple product. It is better, and innovative.

Wait, what?

[Wonko the Sane]

On top of that, they also use numerous precious metals including gold, platinum and silicon.

Gold, sure; platinum, no problem; silicon, WTF?

Currently used as a strengthening agent in plastic, molybdenite is abundant in the natural word. Speaking to the BBC, Prof Andras Kis, the director of the Laboratory of Nanoscale Electronics and Structures (LANES) in Lausanne, said that his team’s research could transform the world of computing. ”[Currently] there is something like 19 million metric tonnes around,” Prof Kis said in an interview. ”You can just go on some websites on the internet and buy a 1cm by 1cm crystal for around $100 [£64].”

Abundant as compared to what? Silicon is the third most abundant element on earth and makes up 15% of its mass. Molybdenum is a rare earth element. Also, you can't use the current price of some element based on it not being used to make microprocessors and expect that the cost won't change if you increase the demand for it by many orders of magnitude. There might be good reasons for building microprocessors from molybdenite but replacing scarce silicon with abundant molybdenite is not one of them.

Re:Wait, what?

[ardor]

I tend to agree, however, keep in mind:
Silicon is abundant. Highly pure silicon is not. You need the latter for microchips.

Re:Wait, what?

[Gaygirlie]

Gold, sure; platinum, no problem; silicon, WTF?

Yes, the molybdenite is used as the primary material in crafting the transistors themselves, silicon is used for the packaging and insulation.

Abundant as compared to what? Silicon is the third most abundant element on earth and makes up 15% of its mass. Molybdenum is a rare earth element. Also, you can't use the current price of some element based on it not being used to make microprocessors and expect that the cost won't change if you increase the demand for it by many orders of magnitude.

There might be good reasons for building microprocessors from molybdenite but replacing scarce silicon with abundant molybdenite is not one of them.

While it's true that there is a lot of silicon on Earth, it however cannot just be mined and used directly. The silicon must be purified to a very high degree before it can be used in microchips and that is costly and consumes a lot of silicon.

Re:Wait, what?

[Anonymous Coward]

Molybdenum is not a rare earth element (lanthanoid), it's a transition metal.
And rare earth elements are not neccessarily rare.

Re:Wait, what?

[vikingpower]

Molybden(i)um most frigging certainly is NOT a "rare earth element". It belongs to the iron group, along with e.g. Vanadium, Chrome, Nickel and, well, yes, Iron. Molybden(i)um occurs in extractable concentrations on almost all locations where iron ore is abundant.

Re:Wait, what?

[compro01]

Well, silicon is a metaloid, and by price, ultra-high-purity silicon is certainly precious.

A 300mm IC-grade wafer costs about $150. Weights about 1.6 grams.

That's about $93,000/kilo. Gold is about $55,000/kilo.

Re:Wait, what?

[Algae_94]

That price drops dramatically if you drop the wafer and break it.

Duplicate. Old news. Nothing to see here...

[Anonymous Coward]

This has already been reported: http://science.slashdot.org/story/11/01/31/021258/molybdenite-as-an-alternative-to-silicon

And yes, they're the same. They link to the same Nature Nano article...

Molybdenite occurs with radioactive Rhenium-187

[G3ckoG33k]

Molybdenite occurs together with Rhenium-187 which is radioactive. http://en.wikipedia.org/wiki/Molybdenite

Is that a serious issue here?

Re:Molybdenite occurs with radioactive Rhenium-187

[NEDHead]

Perhaps it can become a self powered chip?

More info

[Geoffrey.landis]

Moly disulfide is mostly known as a lubricant.

Interesting, but I wouldn't sell my stocks in silicon electronics yet. Silicon is way down the learning curve. I wouldn't bet a new semiconductor against it.

Some of what the article says is a little dubious, like the fact that silicon "The surface likes to oxidise - it likes to bind with oxygen... and that makes its electrical properties degrade when you want to make a very thin film." Yes, it forms oxide easily. No, that doesn't "degrade" the electrical properties-- in fact, this is exactly why silicon is so incredibly useful in electronics. Oxide, and the fact that silicon oxide passivates the surface to prevent electron-hole recombination at the dangling bonds, is what makes silicon electronics possible. I note that the moly disulfide transistors use hafnium oxide for a gate. That's a high dielectric constant material that is indeed also used in silicon, but the silicon oxide is still the critical interface.

By the way, I think there's slightly better info from eetimes http://www.eetimes.com/electronics-news/4212757/New-material-for-semis-said-to-beat-silicon or physicsworld http://physicsworld.com/cws/article/news/45056

Re:So soon.

[rwise2112]

But also come several years later, and still be the first!

Molybdenum element 42..

[Anonymous Coward]

What I can't believe no one has pointed out yet is that one of the primary elements in Molybdenite is Molybdenum, which is the 42nd element in the periodic table. 42 = The answer to the ultimate question of life the universe and everything. Therefore this has to be the best answer to any microchip issues QED