Strained Silicon Chips From Intel

Quirk writes "NewScientist is reporting... "Intel has taken the wraps off a secret technique it is using'Strained silicon' chips to increase the speed of its Pentium and Centrino chips. The technique boosts the rate at which transistors switch, without having to make them smaller.""

Comments

Since when is Strained Silicon Secret?

[RalphBNumbers]

I know IBM has been publically working with this, at least in research, for a long time, and it's a fair bet other firms were too.
IIRC they've even used SSoI (Strained Silicon on Insulator) for some production ASICs...

Re:Since when is Strained Silicon Secret?

[metlin]

During my undergrad, one of my professors of Solid State Circuits lab talked about this. She said that the reason this is hard is because when your source/gate region is partially depleted of charge carriers, there is a need to raise the source-drain gates effectively to utilize the technology. You see, one of the benefits is that the effective capacitance of your source-drain region is decreased. However, if your source-drain gates are not sufficiently increased, the remaining charge carriers remain back and over a period of time this in itself builds up a capacitance. It then begins to function like a dual capacitor device, etc.

And to counter this, you will end up using metal within your S-D zone, however that will have its own side effects - you will need more interconnects and this will increase the resistance by a very slight amount. Trivial for a small number of transistors but if you're having a few million of them, it could be painful. Also, it would mean that the entire thing is going to heat up ever so quickly.

And ofcourse, you always have issues with the Floating Body effects (warning Powerpoint).

Couple this with a hard manufacturing process, and you have a technology thats atleast going to take another 5-10 years to mature. And thats being optimistic :)

Mechanical Stress

[miracle69]

All of this is at the atomic level, but I do wonder how these things hold up to mechanical and thermal stress.

To stretch the silicon lattice, Intel deposits a film of silicon nitride over the whole transistor at high temperature. Because silicon nitride contracts less than silicon as it cools, it locks the silicon lattice beneath it in place with a wider spacing than it would normally adopt. This improves electron conduction by 10 per cent.

What temperature ranges does this become an issue? If my processor gets warm, will its performance decrease because the strain dissapeared?

Would mild mechanical stress on the chip (i.e. application of heat-sink) alter the strain?

Way behind competitors still

[MBraynard]

Man made diamonds have much less problems handling heat and Intel is ignoring this while their competitors are on the fast track.

Still, Butler is frustrated with what he thinks of as myopia in the US computer business. "Europe and Japan have been investing in diamond semiconductor research," he says, citing the Japanese government's announcement in December that it would begin allocating $6 million a year to build a first-generation diamond chip. "Bob Linares has given the US the advantage, but nobody's paying any attention," he says. "If we're not careful, the Japanese or the Europeans are going to claim the diamond niche."

Indeed, Intel's top materials executives weren't aware of the latest research breakthroughs when I spoke to them in June, although they certainly understood the potential for diamonds in computing. "Diamonds represent a seismic change in semiconductors," says Krishnamurthy Soumyanath, Intel's director of communications circuits research. "It takes us about 10 years to evaluate a new material. We have a lot of investment in silicon. We're not about to abandon that."

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