ken@argus.UUCP (Kenneth Ng) (12/01/89)
In article <1Tcfjq#9jMTbv=eric@snark.uu.net>, eric@snark.uu.net (Eric S. Raymond) writes:
: If you're the gambling type, bet your bux on ballistic-transistor technology
: or indium phosphide or even nanotechnology rod logic. But forget GaAs. It is
: almost certainly doomed to remain a niche technology funded by organizations
: that don't care how much of your money they spend for their fun.
Hm, indium phosphide I once heard that mentioned by Cray (yes that
Cray), but I never heard of nanotechnology rod logic. Is it real
or is it a joke of some kind? Does anyone know of anyone working
with indium phosphide at least?
: Eric S. Raymond = eric@snark.uu.net (mad mastermind of TMN-Netnews)
--
Kenneth Ng: Post office: NJIT - CCCC, Newark New Jersey 07102
uucp !andromeda!argus!ken *** NOT ken@bellcore.uucp ***
bitnet(prefered) ken@orion.bitnetdawill@hubcap.clemson.edu (david williams) (12/01/89)
In article <1376@argus.UUCP>, ken@argus.UUCP (Kenneth Ng) writes: > In article <1Tcfjq#9jMTbv=eric@snark.uu.net>, eric@snark.uu.net (Eric S. Raymond) writes: > : If you're the gambling type, bet your bux on ballistic-transistor technology > : or indium phosphide or even nanotechnology rod logic. But forget GaAs. It is > > Hm, indium phosphide I once heard that mentioned by Cray (yes that > Cray), but I never heard of nanotechnology rod logic. Is it real > or is it a joke of some kind? Does anyone know of anyone working > with indium phosphide at least? As much as any nanotechnology is "real", nanotech rod logic is real. Look at it this way: Rather than having various electrical signals, the nanotech stuff works mechanically, since they are so small that electrical stuff just overwhelms it. Suppose our logic worked by having little bitty rods that get shuttled back and forth: for example, an and gate would have a rod that would be pushed to the on state when both input rods were pushing on it. An OR gate would be really simple: input 1 --- | | ----- output input 2 --- | If either input rod gets pushed on, it would push the bridge and thereby push the output rod. You can play all sorts of mind games building this sort of logic. Considering how *small* this stuff is, it should be able to react really fast. Building it would be tough, though. Dave Williams dawill@hubcap.clemson.edu (signature macro on other computer)
jdarcy@pinocchio.encore.com (Jeff d'Arcy) (12/01/89)
From article <1376@argus.UUCP>, by ken@argus.UUCP (Kenneth Ng): > Hm, indium phosphide I once heard that mentioned by Cray (yes that > Cray), but I never heard of nanotechnology rod logic. Is it real > or is it a joke of some kind? Does anyone know of anyone working > with indium phosphide at least? While we're at it, what is "ballistic transistor" technology. I see images of microchips with little microrocket engines, but somehow I don't think that's what ER was talking about. Jeff d'Arcy OS/Network Software Engineer jdarcy@encore.com Encore has provided the medium, but the message remains my own
webber@psych.toronto.edu (Bob Webber) (12/01/89)
In article <10508@encore.Encore.COM> jdarcy@pinocchio.encore.com (Jeff d'Arcy) writes: >While we're at it, what is "ballistic transistor" technology. I see >images of microchips with little microrocket engines, but somehow I >don't think that's what ER was talking about. > >Jeff d'Arcy OS/Network Software Engineer jdarcy@encore.com > Encore has provided the medium, but the message remains my own A simplified explanation: electrons are accelerated towards the gate so that the delay time between a change of state at the gate and the beginning or cessation of arrival of electrons on its far side is shorter than it would be if the electrons simply diffused across as they do in a conventional transistor. This entails building a more complex structure for each transistor, and I recall/believe that more connections are required since one must apply an accelerating voltage. Incidentally, I don't understand why InP (indium phosphide) should be thought superior to GaAs at this stage of development. Both are III-V compound semiconductors, both are therefore inherently more difficult to work with than Si or Ge, and the fact that InP is less well developed may simply mean we haven't seen its worst problems. Arguments based on the toxicity of As are beside the point: fabrication of small-scale multi-layer devices on a commercial scale seems currently to require the use of organometallic reagents. It seems unlikely that any of these will be non-toxic. For that matter, seems to me that there's folks using phosgene as a P source for doping Si someplace on campus...
beyer@cbnewsh.ATT.COM (jean-david.beyer) (12/01/89)
In article <1989Nov30.230012.11752@psych.toronto.edu>, webber@psych.toronto.edu (Bob Webber) writes: > In article <10508@encore.Encore.COM> jdarcy@pinocchio.encore.com (Jeff d'Arcy) writes: > >While we're at it, what is "ballistic transistor" technology. I see > to require the use of organometallic reagents. It seems unlikely that > any of these will be non-toxic. For that matter, seems to me that there's > folks using phosgene as a P source for doping Si someplace on campus... I thought they used Phosphine (PH3) and Arsene (AsH3) as doping agents. I do not recall the formula for phosgene, but do not think there is phosphorus in it. Is it not a compound similar to carbon tetrachloride? -- Jean-David Beyer AT&T Bell Laboratories Holmdel, New Jersey, 07733 attunix!beyer
mbutts@mentor.com (Mike Butts) (12/05/89)
From article <7269@hubcap.clemson.edu>, by dawill@hubcap.clemson.edu (david williams): > In article <1376@argus.UUCP>, ken@argus.UUCP (Kenneth Ng) writes: >> In article <1Tcfjq#9jMTbv=eric@snark.uu.net>, eric@snark.uu.net (Eric S. Raymond) writes: >> : If you're the gambling type, bet your bux on ballistic-transistor technology >> : or indium phosphide or even nanotechnology rod logic. But forget GaAs. It is >> >> Hm, indium phosphide I once heard that mentioned by Cray (yes that >> Cray), but I never heard of nanotechnology rod logic. Is it real >> or is it a joke of some kind? Does anyone know of anyone working >> with indium phosphide at least? > > As much as any nanotechnology is "real", nanotech rod logic is real. > Look at it this way: Rather than having various electrical signals, the > nanotech stuff works mechanically, since they are so small that electrical > stuff just overwhelms it. Suppose our logic worked by having little bitty > rods that get shuttled back and forth: for example, an and gate would have > a rod that would be pushed to the on state when both input rods were pushing > on it. An OR gate would be really simple: > > input 1 --- | > | ----- output > input 2 --- | > > If either input rod gets pushed on, it would push the bridge and thereby > push the output rod. > You can play all sorts of mind games building this sort of logic. > Considering how *small* this stuff is, it should be able to react really > fast. Building it would be tough, though. > > Dave Williams dawill@hubcap.clemson.edu (signature macro on > other computer) Nanotechnology is a *hypothetical* technology of building molecular-scale machines by assembling individual atoms at the atomic level. It is predicted by Eric Drexler of MIT in his book "Engines of Creation" to be the ultimate outgrowth of such technologies as DNA construction and scanning tunneling microscopy. Large nanocomputers the size of biological cells would operate mechanically at GigaHertz speeds. Many other quite revolutionary applications, and their social consequences, are envisioned, with quantitative basis and including references to other literature. Also check newsgroup sci.nanotech. -- Michael Butts, Research Engineer KC7IT 503-626-1302 Mentor Graphics Corp., 8500 SW Creekside Place, Beaverton, OR 97005 !{sequent,tessi,apollo}!mntgfx!mbutts mbutts@pdx.MENTOR.COM Opinions are my own, not necessarily those of Mentor Graphics Corp.
mcdonald@aries.uiuc.edu (Doug McDonald) (12/06/89)
At our departmental seminar yesterday the speaker showed fabricated areas on mica as small as 1 nanometers. These are just basically scratch marks. But is is easy to do and a start. And other materials work also. This was done with the "scanning microscope" technology. His pictures of steps on ordinary silicon chips were stunning - you could see the literal atoms of the tops and sides of mesas. Doug McDonald
TOMASIC@RICEVM1.BITNET (ZDENKO) (12/06/89)
Phosgene is carbonyl dichloride (COCl2), a product of pyrolisis of carbon tetrachloride (CCl4). It is a very poisonous lacrymator. (BTW A good reason to keep it out of this newsgroup). Zdenko Tomasic Rice University Chemistry Department Internet:zdenko@katzo.rice.edu
mac@ra.cs.Virginia.EDU (M. Alex Colvin) (12/08/89)
nanomachines (or anything else) built with scanning microscopes can't be very complex, or they'll take to long to build. the nice thing about photolithography is that it's relatively independent of the nummber of features.
mmm@cup.portal.com (Mark Robert Thorson) (12/13/89)
mac@ra.cs.Virginia.EDU (M. Alex Colvin) says: > nanomachines (or anything else) built with scanning microscopes can't be > very complex, or they'll take to long to build. the nice thing about > photolithography is that it's relatively independent of the nummber of > features. On the contrary, they are the same. An STM-fabricated device is built piece-by-piece from atoms and small molecules. An IC mask is made by a machine called a "pattern generator", which has a precision slit controlled by motors. Each line and rectangle is made individually. When it comes to production, photolithography is at an enormous disadvantage. Every single IC must be exposed to a copy of the mask (actually several masks, a dozen or more). An STM-fabricated self-reproducing nanomachine would only need to be manufactured once, after which each unit could be used to make others, much in the manner of a bacteria or algae. The problem is keeping it under control. *** With regard to GaAs, I heard that the oxide is conductive. Think about that for a moment, and you'll understand why it could be so much harder to make than silicon (in which oxygen and water vapor can be used to grow excellent insulating material).