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From: davidsen@crdos1.crd.ge.COM (Wm E Davidsen Jr)
Newsgroups: comp.arch
Subject: Re: chip cost
Message-ID: <2862@crdos1.crd.ge.COM>
Date: 8 Nov 90 21:45:51 GMT
References: <35325@cup.portal.com> <1990Oct30.210852.15087@mozart.amd.com> <2857@crdos1.crd.ge.COM> <27547@mimsy.umd.edu>
Reply-To: davidsen@crdos1.crd.ge.com (bill davidsen)
Organization: GE Corp R&D Center, Schenectady NY
Lines: 35

In article <27547@mimsy.umd.edu> chris@mimsy.umd.edu (Chris Torek) writes:

| As I understand it (this information comes from my younger brother, who
| is doing device research at Penn State) you can shrink as much as you
| want.  The problem is that yeild goes to zero.  (`We put 100 billion
| angels on the head of this pin.  The only problem is, they are all
| dead.'  `Yeah, but can they still dance?' :-) )  

  You have it right. To go smaller will either cost more to keep the
same yeild, or give lower yeild. Either way the actual cost per working
chip is likely to go up. Vendors have tickled their processes so that
the cost goes up less than the yeild goes down, and the net cost of a
chip then goes down.

  One problem is that making small features has a price jump as you
reach the limit of resolution in visible light. Vendors went to UV, and
I don't know what they're using now (other than here, which I would ask
before stating). Other tricks include a coating which makes the cuts
cleaner (the edges of a feature are more nearly perpendicular to the
surface, and I'm sure other tricks, too.

  I'm fairly sure that a good deal of the early cost of a chip is the
research, and of course it's a lot easier to make a chip than design it.
I'm sure in the long run the prices of chips will fall, because that's
the way the vendor can make the most moeny. You can buy into any
technology at the point where it gets cost effective for you.

  I suspect that the techniques IBM used to write "IBM" in letters which
were something like seven atoms high could be used to build *very* small
chips, I just don't know if the performance would be better than what we
have now. One problem seems to be curable by going to lower voltage to
reduce power dissipation. 
-- 
bill davidsen	(davidsen@crdos1.crd.GE.COM -or- uunet!crdgw1!crdos1!davidsen)
    VMS is a text-only adventure game. If you win you can use unix.