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IBM

Stretched Silicon Speeds Semiconductors 60

byrd77 writes: "IBM is touting new 'strained' silicon as being up to 35 percent faster while reducing power requirements. Let's hope this is more than just an exercise in straining credulity..." See also their press release.
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Stretched Silicon Speeds Semiconductors

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  • by Anonymous Coward
    Ummm... IBM pointed to SOI three years ago and said, "three years to market." Well... you're not excited about it any more because you heard about it three years ago, but they're on schedule. There are a number of other examples (1 GB microdrive?) but I'll let you try to remember what they are.

    It's smart to show that your pipeline isn't drying up when people are getting nervous about "next steps".

  • by Anonymous Coward on Friday June 08, 2001 @12:33PM (#165309)
    Why the dubious attitude towards IBM? IBM's discoveries have led to significant breakthroughs in technology. I especially like their GMR technology, and although they DO make money from licensing it (OH NO!!!!!!), it HAS advanced all aspects of magnetic storage substantially. Their SOI technology is also very promising. And look at this, they continue to innovate.

    So why this "LOLOL IBM WANTS MONEY!!!" commentary? They're a corporation, yes, but their inventions have a wonderful impact on computers.
  • by Anonymous Coward on Friday June 08, 2001 @12:20PM (#165310)
    welcome to my forum for technical hooey. since this post is about a substantial accomplishment made by someone other than me, here is my standard /. bitch response:

    1. It'll never work - thats right, if the Ph.ds at the IBM lab had consulted me and my RPG-playing zit-studded freshmen pals, they would have understood how idiotic they were to pursue this work, and to claim that it was a success.

    2. Those greedy bastards - how dare they hold this innovation closely and not share it with openwhatever.org?

    3. What does this have to do with linux? Philip Greenspun is cool! Craig Mundie sucks dick! RMS and Linus rule too! Steve Case also sucks dick!

    Thank you, this is /. bitch, signing off.

  • How about SOI (silicon on insulator) or Copper chips? These are both available right now....
  • This sounds a lot like the speech software
    you describe:

    http://www-4.ibm.com/software/speech/enterprise/ te _1.html

    -Kevin
  • I agree that strained silicon is a common source of research - that was the point of my post: exactly what did IBM do that causes this to be a breakthrough.

    Also, I was not talking about the material properties of SiGe - but of strained Si on a SiGe lattice which is exactly what this press release was about.

    Going through each of the points that I mentioned as downsides of the technology:

    1. Thermal conductivity: this is a property of the bulk material. Even if the SiGe material is epitaxially deposited on a bulk Si wafer, there will still be a substantial layer of SiGe between the transistors and the bulk material. In flip-chip BGA technology cooling of a chip is from the backside - through the substrate. The substantially lower thermal conductivity of the graded SiGe material used to created the strained silicon lattice in the channel is fairly large and will act to isolate the transistors from the backside cooling, which will induced localized self-heating near the transistor. The temperature of the transistor will rise due to this effect which will reduce the mobility of the device.

    2. Junction leakage: the lower conduction band in strained Si will lead to reduced Vt within the channel. This reduced Vt will contribute to enhanced switching performance, but will increase Ioff - the source/drain current that flows when the device is supposed to be off. If the process is modified to increase this Vt, then the mobility will be reduced.

    3. The dielectric constant of SiGe - which forms the subtrate under the source and drain is substantially higher than the dielectric constant of Si. The parasitic junction cap in the source and drain to the substrate will thus be higher - not substantially but noticeably.

    I would be interested to know on what basis you disagree with these three points. I have followed this subject with interest through my career as a microprocessor design engineer and consider myself very familiar with the issues involved and so I am very curious about the details of what they did.

    Which leads back to my question - how did IBM solve these issues - particularly the first one - and if they didn't, then what makes this a breakthrough?
  • by pm ( 11079 ) on Friday June 08, 2001 @01:56PM (#165314)
    My first question is that researchers at IBM's Research Lab have been working on this for IBM for literally years. I remember reading papers from IBM on this exact same subject back six or seven years ago. They've been fabricating devices back in strained Si/SiGe interfaces and has been presenting papers documenting the mobility improvement for some time now. So the thing that I find truly puzzling is what is the breakthrough? It's not that I don't think this is great, but I fail to see what they are doing now that they weren't doing before.

    So what is strained silicon - essentially it's a way of using the lattice mismatch of silicon and SiGe (silicon germanium) to create tensile strain near the material interfaces. This strain reduces carrier scattering and thus improves mobility for both electrons and holes in the inversion layer of the transistor channel. So, in less engineering speak, the charge carriers in the transistor move around easier and thus faster which improves transistor performance. This mobility improvement can be as high as 70% faster than 'normal' silicon channels.

    It's worth mentioning the downsides of this technique - which I notice have been ignored in all the articles that I have read. Thermal conductivity of strained SiGe is substantially lower than 'normal' silicon - like an order of magnitude less. So the devices will be much hotter. This 'self-heating' of the devices results in reduced mobility of the charge carriers due to increased carrier scattering - so essentially the devices are so much hotter than they greatly reduce the effect that was created in the first place. Another issue is the fact that junction leakage is much higher. And another is that the higher dielectic constant and lower band-gap of SiGe result in higher junction capacitances in the transistors.

    The technology is interesting, but I don't see how they managed to address the issues that have held back the technology so far. It's a shame that they didn't mention potential issues and how they worked around them in the press release, but I guess we'll have to wait for the technical papers at this year's conferences.

    * Not Speaking for Intel Corp. *
  • IBM is using Silicon On Insulator to make microchips these days. In an SOI process the silicon you actually make the transistors on is very thin, at most a few microns, and beneath that is an insulator, such as SiO2.

    If instead you do epitaxial Si deposition on another insulating crystal, perhaps sapphire, with a lattice slightly larger than Si's, you get the benefits of an SOI process *and* this improvement from a strained lattice.

    This is a real technical coup on IBM's part.

    As for diffusion, well, IBM can use dopants with lower diffusivities should this be a problem for part longevity.

  • by DarkMan ( 32280 ) on Friday June 08, 2001 @12:22PM (#165316) Journal

    When silicon is deposited on top of a substrate with atoms spaced farther apart, the atoms in silicon stretch to line up with the atoms beneath, stretching -- or "straining" -- the silicon.


    So, you need to build the silicon on top of a substrate, with a similar crystal surface, but a larger lattice parameter(s). Then grow the silicon on top of it by some technique that maintains atomic level consitancy between the layers.

    This is difficult to do - your basically talking something along the lines of silicon deposited by some for of epitaxial growth - and for thick layers that's a timeconsuming process. And thus expensive.

    One thing that was not mentioned was the cost of this trick - how does it compare with germanium or gallium arsnide? (Ok, projected to compare?).

    I think that, baring some lucky find, this is going to be more expensive than the befefits, for general use.

    Not only that, but the interdiffusion coefficents of a strained material are, in general, faster than for the an unstrained material, so this will decrease the lifetime of the devices.

    Interesting idea, though.
    --
  • Yeah - really!

    Slashdot provides a forum for some perpetual life nut-job, then questions the credibility of IBM.

    I'm beginning to question what on earth these goons are smoking. I'd be scared to try it myself.

  • by inl101 ( 35878 ) on Friday June 08, 2001 @12:40PM (#165318)
    This is difficult to do - your basically talking something along the lines of silicon deposited by some for of epitaxial growth - and for thick layers that's a timeconsuming process. And thus expensive.


    True, but all high-performance device wafers start out with a layer of epi anyway to have a higher quality film than CZ (less oxygen intersticials for example).



    One thing that was not mentioned was the cost of this trick - how does it compare with germanium or gallium arsnide? (Ok, projected to compare?).


    GaAs and Ge are very expensive, and it's hard to produce substrates much larger than 4". I'm sure IBM's strained SiGe can be grown on 12" wafers.


    Not only that, but the interdiffusion coefficents of a strained material are, in general, faster than for the an unstrained material, so this will decrease the lifetime of the devices.


    Also true, which is a concern at front-end processing temperatures, but this is typically not a failure method at room temperature.


    This is not to say that there aren't a lot of manufacturing and reliability issues associated with SiGe devices.

  • ... googly moogly!

    This must by the first time in months an AC has been moderated up to +5.

    Wow. I'm not the only guy who moderates at -1...

    -grendel drago
  • Once again, IBM claims to have invented a new amazing technology. Every time I read something about IBM on Slashdot, it's always something very promising, like new dense storage mediums.
    But I'm still waiting to see any product that uses their discoveries. It's so disapointing "yeah, we have something that really rocks. But you can't buy it now".
    IBM does a marvellous research work, but maybe their press releases are coming too early, they give us fale hopes.
  • In an age of pushing the envelope where even "compatible" mobo/CPU combos can be unstable because of manufacturing deficits we now add an additional source of strain to the hardware.

    I give up, where's my 486?

  • I just hope the chips resulting don't anneal and slow down if they get too hot.

    That would kind of make overclockers shoot themselves in the foot.

  • ...and I'd like to see it happen (if this is real), but for all they show off about low time-to-market, I doubt we'll be seeing these too soon, more's the pity :-(

    Don't be too discouraged. Copper interconnects in IBM's chips didn't take nearly as long as I saw some people predicting.

  • IBM does a marvellous research work, but maybe their press releases are coming too early, they give us fale hopes.

    Depends.

    Sometimes IBM manages to get stuff out fairly quickly(like copper interconnects on chips).

    OTOH, I think it's been about a decade since I watched on CNN a demo of IBM voice-recognition software that was supposed to eliminate the need for keyboards, and allow you to easily dictate in documents, where synonyms ("to", "too", "2", et cetra) were corrected based on context and so on.

    I couldn't help but notice however, how in the demo the software kept getting ahead of the demonstrator, "correctly predicting" and displaying things like a specific noun in a sentence before it was uttered, evidently based merely on her having begun the sentence with the word "The"...

  • When are the going to "lay" it out in three dimensions?

    Probably when they develop a 4-dimensional projector that will allow them to project a solid shadow of a 3-D mask into the inside of a block of silicon, and a teleportation device to get the dopant atoms inside.

  • Or, when they develop completely self organizing semiconductors that can be quickly grown from a single nucleation point.

    I am not sure which is more likely :)
  • I didn't even know Joan Rivers was in the microprocessor industry.

    Way to go Joan.

    Oh, _silicon_!
  • edge effect and RC delays are in the wires (Al/Cu), not the Si - speeding it up isn't going to speed up the interconnect.

    I must admit I only read the press release link which only refers to '35%' not '70%' - 35% is reasonable from 70% if you assume that delays are evenly shared between gates and nets - of course my experience is that while that's true for most paths the ones that come and bite you are the long nets that are mostly RC

  • by taniwha ( 70410 ) on Friday June 08, 2001 @12:20PM (#165329) Homepage Journal
    It used to be that silicon speedups like this were a really big deal - sadly at today's geometries wire speed is as important, or more important than silicon speeds.

    These days even process shrinks don't give use the speedups they used to (edge effects, RC delays and all that) - however everylittle bit helps - 35% faster silicon probably means 10% faster chips overall - what we really need is a new way to do interconnect - lasers? room temp superconductors? quantum comunications ["I put a cat in my box I don't know if it's dead why don't you check to see if there's any food missing at your end?" :-]? esp? etc etc

  • Exactly. Remember that only three years ago I bought an 8 gig HD. Now I can buy one from IBM that's 75, something that IBM is directly responsible for with their development of new hard drive technologies (that, coincidentally, i remember reading about only one or two years ago).
  • by displacer ( 136053 ) on Friday June 08, 2001 @12:28PM (#165331)
    Check out the picture at this article [yahoo.com]at Yahoo.
  • What's wrong with roleplaying?

    -- And believing that scientific knowledge should be available to everyone? Yes, IBM paid to discover it. No, that doesn't make the knowledge theirs. If I discover it tomorrow, I'll do with it as I choose (no disrespect to the researchers at IBM or the people who support them).

    I can't demand that IBM provide it to openwhatever.org, but there's nothing wrong with asking!

  • AMD has been using IBM's new-ish copper interconnect technology for almost a year now, and I have little doubt that we'll be seeing SoI processors from them very soon, too. I know that Thorooughbred (followup to the just released and tweaked 180nm Palomino/Athlon 4/MP) will be a process shrink from 180 to 130nm, but I disrecall whether it will be SoI. If not, the x86-64 "Hammer" will make a showing with .13 micron, copper, and SoI technologies in H2'02.

    --

  • by RESPAWN ( 153636 ) <(caldwell) (at) (tulanealumni.net)> on Friday June 08, 2001 @12:14PM (#165334) Homepage Journal

    Since this guy beat me to the punch on the submission, here's the link to the CNN story that I included: http://www.cnn.com/2001/TECH/ptech/06/08/ibm.silic on.ap/index.html [cnn.com]. Just in case anybody wanted it.

    --------------------------------------

  • bringing the athlons to almost no Heatsink levels of temperatures
    linkage?
  • I wonder if/when IBM and Toshiba would cooperate and combine technologies - or if the two technologies are mutual exclusive. Obviously not a lot of technical data is out for real comparison but does anyone else know? I only have rudiments of Chip Design from my EE classes so I don't claim to:)

    Still with the X Architecture [cnn.com] claiming 10% better peformance and 20% less power dicipation combined with the 30% gains IBM claims, there is turning out to be a lot more room before we hit the physical limit of Moore's law.

    Cool.
  • One thing that was not mentioned was the cost of this trick - how does it compare with germanium or gallium arsnide? (Ok, projected to compare?).

    Neither Ge nor GaAs (or any other III-V compound for that matter) can be used to produce ICs using "standard" Si fabrication techniques. The most important reason is the lack of a suitable native oxide for use as the gate dielectric. GeO2 is water soluble, and oxide on GaAs cannot be grown uniformly or with good quality.

    That being said, ICs are produced on GaAs, but using different types of transistors. However, the amount of experience that would have to be acquired to produce, for example, a pentium on GaAs is staggering. In other words, it will not happen any time soon.

  • Actually, the silicon is 70% faster, so the chip will wind up being 35% faster. Much more impressive.

    Does anyone know if this works alongside SOI? And where will these chips wind up? My bet is Apples, since (IIRC) SOI is on the G4 chip.
  • 35% faster silicon probably means 10% faster chips overall
    They're claiming 70% faster silicon (actually 70% faster electrons) resulting in 35% better performance.
  • by SlashGeek ( 192010 ) <petebibbyjr@gma[ ]com ['il.' in gap]> on Friday June 08, 2001 @12:18PM (#165340)
    CNet [cnet.com] News has a video interview with Randy Issac, VP of IBM research on the subject. Pretty good explaination of the technology.

    Real or Windows Media only.

  • Actually, they're claiming that this will be in use by 2003.


  • Your general facts are all correct, however it's been under research for ages. The optoelectronics used at the ends of fiber optics is nearly all strained or strain-compensated quaternary (mix of four seperate types of atoms) semiconductor compounds grown using the epitaxial methods you metion.

    What I presume that this announcement really means is that IBM has now solved all the very problems you describe, to the point where they are now planning on putting it into production.

  • The scientific knowledge is available to everyone now -- I'm sure this will be published in a bunch of journals and will be talked about at conferences.

    If IBM has patented this new manufacturing process (and I'm sure that they have) however, nobody else will be able to use it without working out a licensing agreement with IBM, unless they wanted to get slapped with a lawsuit.

    The scientific knowledge is available to everyone to use and expand upon, but IP law protects IBM's investment from being used by its competetitors -- the IP is a competetive advantage for IBM. What's wrong with that?

  • Not only that, but the interdiffusion coefficents of a strained material are, in general, faster than for the an unstrained material, so this will decrease the lifetime of the devices. Can we say copper?

    Everyone has been using copper for a hell of a long time, and it does the same thing. The interdiffusivity of copper is horrible, and it doesn't stop them from using it. I imagine that this technology has a chance of making it. Just like C-Nanotubes, they make progress on mass-producing these kinds of effects every day.

  • by fantom_winter ( 194762 ) on Friday June 08, 2001 @02:14PM (#165345)
    These days even process shrinks don't give use the speedups they used to (edge effects, RC delays and all that) - however everylittle bit helps - 35% faster silicon probably means 10% faster chips overall - what we really need is a new way to do interconnect - lasers? room temp

    In the strained silicon, electrons experience less resistance and flow up to 70 percent faster, which can lead to chips that are up to 35 percent faster - without having to shrink the size of transistors.

    So, um read the article, please. ... From the article...

  • faster! better! more enviromently friendly! ... at a price.
  • Over the years, a surprising number of innovations have come from stretching materials.

    for example:

    Edwin Land's Polaroid sheets were plasic stretched "just so", aligning the molecules
    to allow only polarized light to pass. The instant cameras came later.

    Gore-Tex is a membrane that allows H20-vapor to pass but blocks H20 drops. It is
    made by sretching teflon "just so", inducing holes of the correct diameter.

    Spring steel is stretched so that the molecules in the alloy align in a way to give it that property.


  • Let's hope this is more than just an exercise in straining credulity...

    Well, it isn't straining credulity, I read it on Slashdot so it HAS to be true!
  • Isotopically pure Si could be grown strained just as well as natural silicon. Should be no problem to integrate the two technologies, assuming each was economically feasible on its own.
  • Not that IBM doesn't do neato stuff, but it's a little hard to get excited about these kind of developments when it seems like everything they do has a 10-year-to-market period.

    Just an observation.

  • Philip Greenspun is cool. Norm Abrams rocks the world of open-source furniture.


    Whatcha doooo with those rollin' papers?
    Make doooooobieees?
  • You forgot:

    4. I didn't understand or even read the underlying post but I'm commenting anyway - Stra1n3d P3as h4ve n0th1ng t0 d0 w1th f4st3r c0pmutters. 1'm unda 2 much str3ss 4s 1t 15! IBM 5uck5!

  • What kind of crack are you smoking? IBM has a very good record of producing technology on the schedule they say they will. Unlike some (Intel, Microsoft, Apple for examples), IBM is pretty carefull about delivering their products on time. There new denser storage mediums are on the market and they did it far faster than anybody else would have been able to do. When IBM makes a theoretical breakthrough they will say that it might be useable in ten years but when they say something like it should be in production in a couple of years they have the tech worked out. It might take them time to get it worked into a production system. That tends to involve restructuring the current system and often changes in building layout and expenditures for the equipment. Big changes in manufacturing of any kind are neither cheap or easy to do. IBM has vastly impressed me with their willingness to deploy new tech as fast as possible and to make their tech available to other companies at prices low enought to allow rapid adoption. IBM could sit back and not license their new chip making technologies to anyone and they would have a significant advantage over the competition.
  • You also forgot "old news! we were doing research on these back in 1816 already when i was a grad student at MIT, they're not great".

  • Yahoo also has their usual list of links and stories in their section as well: http://dailynews.yahoo.com/fc/Tech/Semiconductors_ and_Computer_Chips/
  • I personally think that by 2003 most new tect will involve nano tech and further progression in tech.
  • I tis good to see there is progretion in the silicon materials tech. I see the up shot of it and the way it will benafit 2days tech but surly it is kicking a dead horse...

    In 2003 surly current develpoment tech will be implemented which will not require any silicon tech. most devlopment tech utilise GaAs and other substrates. nano tech is also speeding up the move away from si tech. Intramolecular tech will remove the need altogether.

    end of rant

  • and let's not forget the 1 billion dollars they have pledged this year to linux and port software to everyone's favorite OS. All while open sourcing said software and releasing GD mwave drivers! http://oss.software.ibm.com/developerworks/opensou rce/
  • I am very glad that IBM makes all these breaktrougs on chip making (and on harddisks by the way) but im starting to wonder if IBM stands alone in the research of silicon properties. Because if it keeps up just a little more like this (a few more good inventions/discoveries) you will have to ask IBM permission to produce chips soon. I mean if IBM has patents on all the things that will makes a porcessor fast, less power consumting, cooler, smaller and in the end also cheaper, there will be no compeeting and IBM will be setting the price. Im not saying that they will be "microsoft mean" in their pricing, but one can expect features like that.

  • If my Mom was reading their press release and all the drooling media blather on it, she'd be left with the impression that IBM had just invented something new and spectacular.

    They haven't. Strained semiconductor production and use has been in the labs for *ages*. Nortel and every other company making lasers and optoelectronics components for fiber-optics systems have been using much more exotic strain-compensated quaternary (compound) semiconductor materials systems for ages. And it was all originally "discovered" in public research institutions and universisites.

    All IBM has done is figured out how to work it into their current production line (which is in fact quite an accomplishment).

    Let me know when AMD gets strain compensated SiGe into their CPUs. Then I'll get excited.

  • I wonder if/when IBM and Toshiba would cooperate and combine technologies - or if the two technologies are mutual exclusive.
    A lot of these chip architectures, including the ones we have been seeing lately from AMD, Intel, IBM etc have been concentrating on getting the most out of existing silicon. That is because industries do not want to write off existing fabs. A lot of research goes on interconnect technologies in Europe, and I wonder when all these technologies would be put together. At one point of time, the cost of productising any new technology will become too big even for the biggies, and then mergers will start happening, like in any other industry. Again, money wins.
    The other alternative is to have completely different paradigms of computing like biochips and Quantum comps.
  • Took me a couple of readings to guess which one of those links was the press release, and which one of them was the "news".
  • ...and I'd like to see it happen (if this is real), but for all they show off about low time-to-market, I doubt we'll be seeing these too soon, more's the pity :-(

    43rd Law of Computing:
  • I don't think it is. IBM is a fairly stable company and has been around since before computers. They have no reason to lie, not to mention the fact that they are always doing R&D, and therefore often release news about their developments. If I had money to invest, IBM would be one of my top choices...

  • I meant no fan, always need a heatsink :) This was a month ago or so, I'll look for a link though.
  • http://www.theregister.co.uk/content/3/15121.html There you go, minimal cost, 35C temp drop for a 1Ghz processor, almost no Heat sink needed.
  • its interesting, but AMD is already incorporating a new type of silicon into their chips. The price increase it supposedly quite small, and the performance gain is similar to IBMs technology... but is said to have incredible heat conductive properties, bringing the athlons to almost no Heatsink levels of temperatures. Since this technology AMD is putting in their chips is an extremely pure form of silicon, it might not be compatitible with IBMs research, but you never know.

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