Intel: Metal in Future Chips = Less Leakage (updated)

securitas writes "Intel is contemplating using metal instead of silicon in future chips for the 'transistor gate, which controls whether a transistor is on or off' and the 'dielectric, an insulating layer below the gate,' which are respectively made of silicon atoms and silicon dioxide. 'Millions of minuscule switches that make up silicon chips leak electricity when they're supposed to be shut off. To compensate, engineers have increased the current, driving up power consumption, decreasing battery life for portable devices and generating more heat.' AMD has also experimented with metal instead of silicon. By moving to metal AMD and Intel expect to reduce electricity leakage. More from AP via SeattlePI and the Miami Herald." Update: 11/05 15:25 GMT by T : Read on below for some information from Intel on why this is a good thing.

gManZboy writes "Following up on the Intel news that about using metal in chips -- here's an explanation from Shekhar Borkar (Intel Research Fellow) about why heat, power, and sub-threshold leakage, not transistor size, are the real challenges to Moore's law. Apparently, in order to make chips much faster, we're going to have to pump more electricity in then anything else in our houses -- and they'll soon be as hot as a nuclear reactor -- no, really."

Comments

Which metal?

[msgmonkey]

I dont see any mention of the type of metal that would be most suitable. I'm sure all metals are n't created equal.

Re:Which metal?

[Mr. Troll]

Isn't the next logical step after silicon diamond? Plenty of asian companies are already working on diamond based chips(remember, lab made diamonds are getting CHEAP and bigggeerrr)and if Intel and AMD don't get off their collective asses, they will no longer be the centers of the chip world.

Re:Which metal?

[dustinmarc]

It's a secret. Intel isn't saying what the material is, just that they've discovered a probable solution to fix the achilles heel of the chipmaking industry.

Basically, they are saying that they have found two new materials with a high k dielectric that reduces current leakage by more than a 100 times silicon dioxide and hopefully plan to use it by 2007 in production. They also have tested the materials and had excellent results in a lab environment. Still, they are being vague on the details, and who can blame them if this stuff is as good as they say it is.

Skeptic or beleiver? I guess that's a matter of opinion. But Intel thinks that this will keep Moore's law true for quite some time. In the past if Intel claims they have been able to stay true to Moore's law it's been true. Heck, the can't lie, Moore is the founder of the company.

What about...

[the_bahua]

...diamonds?

I thought that the manufacture of diamonds was set, and only needed to step up its production. Gemesis has been making, for less than $100, gems that would be worth hundreds of thousands if naturally mined.

The most promising thing about these diamonds is that, being cheap, they open the door for cpu cooling. Diamonds are tolerant of exponentially higher temperatures than silicon, so why aren't we hearing about intel, amd, motorola, ibm, TI, and sgi taking advantage of this new technology.

Metal? What about metal is unprecedented? What about it has kept us from using it before? Diamonds are the future, not metal.

Re:Metal dielectric!?

[brassman]

A metal dielectric does sound like voodoo... but at the scale they're describing -- four ATOMS thick!? -- I suspect it's more of a waveguide (or perhaps a forcefield) than a physical barrier.

I'm no expert, but...

[doublebackslash]

I suspect that the meatal they are going to be using will be doped with something else, or impure or part of an oughtright compund. Just like "Sodium" in your diet just happens to be bonded to some chlorine. I have no idea how they get away with this sort of thing.

Diamond

[rogue555]

Just make 'em out of diamond and all your problems are solved. Great heat transfer coeficient so you don't have to worry about heat anyway.

Hadn't IBM already done this

[adzoox]

I was aware that IBM's copper on silicon insulator already acheived less leakage and less power consumption, also increasing power (per Mhz) in each cycle. G3's (for Apple Computers have had this for over 2 years) and G5's also have it.

Interesting how IBM has discovered that moving to metal for processors and away from metal for hard drives. (Newest Hitachi/IBM notebook drives use Pixie dust which is actually glass. The platters in these hard drives are also ferro impregnated glass platters)

Re:Hadn't IBM already done this

[Oo.et.oO]

you are thinking of SOI (silicon on insulator) which allows for less DRAIN current leakage to the substrate. this of course has nothing to due with the copper interconnects in the BEOL.

all existing technologies in production (AFAIK) use poly gates as it survives the anneal and etching steps which copper and aluminum could never do in current configurations

Re:Hadn't IBM already done this

[adzoox]

No, the SOI is something different - it IS used in the G5's but G3's (750fx & Gx) used copper interconnects as well. It was the way that IBM figured out how to make the G3 so effiecient. The 900Mhz G3 is probably the coolest/best performing/per Mhz of any processor released in the past 3 years.

Re:Hadn't IBM already done this

[addaon]

The 900Mhz G3 is probably the coolest/best performing/per Mhz

Except of course for the same chip (the 750FX) at, say, 600MHz, or less. The G3 is seriously bandwidth-starved in most configurations I've seen (it supports a 200MHz FSB, but I've never seen it used with more than 167); scaling down the clock-speed gives sub-linear decrease in performance, linear (well, close enough; moreso than for most non-arm chips) decrease in heat and power consumption.

Don't get me wrong, the 750FX is, in my opinion, the nicest piece of silicon yet produced (and I'd much rather have a 4-core G3 than a 1-core G5 with the same number of transistors)... but people (and, of course, in particular apple) need to realize that this chip had dual phase-locked-loops and takes less time to switch clock speeds than to switch processes... dynamic scaling is Good, constant 900MHz (or 900MHz and then, blindly, 600Mhz when unplugged from the wall) is Silly and Bad.

Re:Metal dielectric!?

[Drakin]

Well, if I recall correctly, tantalum oxide is dielectric, so it's possible that they it, rather than a pure metal.

Pure tantalum on the other hand, is a great conductor.

Heat=power

[nagora]

If the chip in your computer is as hot as a nuclear power station, should you not do what power stations do and hook it up to a steam turbine?

One day, your computer may be the ONLY thing in your house connected to the outside mains supply!

TWW

The Apollo process, not Gemma

[TubeSteak]

The Apollo Method (Skip to the end of the article)
1. Place diamond wafers on pedestal. Depressurize chamber to one-tenth of an atmosphere.
2. Inject hydrogen, natural gas (CH4) into chamber. Heat with microwave beam. At 1,800 degrees Fahrenheit, electrons separate from nuclei, forming plasma.
3. Let it rain. Freed carbon precipitates out of plasma cloud and is deposited on wafer seeds.
4. Let it grow. Wafer seeds gradually become diamond minibricks, building up at half a millimeter a day.
5. Open chamber and remove diamond brick. Slice into wafers for semiconductors or cut and polish to make gems.
6. Profit!!!

DeBeers and Co. are very very unhappy about these two technologies and what they're going to do to diamond prices. Both companies can create perfect diamonds and the second manufacturing process will allow (once its been scaled up) for diamonds to be used in electronics.

But here's the reason the U.S. might just end up behind the technology curve:

"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."

...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...

Also, some other posters have commented on impurities being a stumbling block for diamond-based electronics, how convienent that "CVD diamond precipitates as nearly 100% pure"

Re:Clueless, thy name is reporter

[Anonymous Coward]

The article make no mention of what the gate is composed of, but they offer a hint. The confusion comes from calling it a "metal gate". Back in olden days, we only used metal gates composed of Al. Unfortunately, there was a limit to how thin the silicon dioxide gate insulator could be made, because the Al would diffuse through and kill the transistor. This is why polycrystalline silicon (poly-si) is used for the gate conductor material.

There seem to be two advances proposed here. One is to replace the poly-si gate conductor with a metal conductor of unknown composistion. Al is likely because of its current use in lower level interconnects (Cu can't be too close to the Si). Al has way higher conductivity than poly-si, so there would be a speed increase.

The "high-k" (high dielectric constant) material is a metal oxide, likely TiO2, ZrO2, or HfO2. These are dense films, which would act as a diffusion barrier for the Al gate, circumventing the old problem solved by the poly-si gates. In addition, the higher dielectric constant (20-50, or so, compared with 3.9 for SiO2) would greatly increase gate capacitance, which directly affect transistor gain (increased speed).

Moore's Law or self-fulfilling prophecy?

[G4from128k]

Moore's Law is a market imperative, which to a business is pretty much the same thing as a law.

Interesting insight. I wonder if there is an accidental collusion among semiconductor companies to limit their progress to Moore's observed trend? It seems suspicious to me that the trend should continue for so long without an obvious physical cause. In my orginal post, I suggested that mental and procedural limits kept companies for doubling faster than Moore's Law -- people just don't seem to create magic breakthroughs that double the transistor count in 3 months.

But now I wonder if Moore's law is a self-fulfilling prophecy. Everyone (semiconductor makers, software creators, and chip customers) knows about the Law, so everyone obeys it. Rather than spend time doubling the transistor count in a very short time, companies stick to the industry trend and spend time on other advances (e.g., innovations in microcode, cache, bus, branch-prediction, etc.)

The point is that in business, you need only beat your competitors by some incremental value. Thus, there is little incentive for Intel, for example, to double transistor count in 6 months as few customers would pay much more for the new breakthrough-density processor than they would for a competition-beating processor that only doubles on an 18-24 month schedule.

Perhaps Moores Law holds because everyone obeys it -- makers are too afraid to go slower and there's little competitive advantage to going much faster.