🚀 go-pugleaf

In article <261500011@S41.Prime.COM> CIS@S41.Prime.COM writes:
>It would be interesting to see the follow-up paper on how the fab process was
>improved for 64K RAMs.

I got mail from a friend about this; I probably shouldn't identify him
since I haven't checked with him on it.  His comment was that the paper's
main mistake was to assume that full-wafer mask-in-contact-with-chip
technology was the limits of optical processing.  In fact, the way most
chip companies solved the problem was to go to wafer steppers (as I
understand it, these are projection rather than contact systems, and
expose only part of the wafer at a time), which bypassed the limitations
of the full-wafer contact process.  This *did* take time and money, so
he wasn't entirely wrong in predicting some delay.

As it turned out, eventually a full-wafer projection system showed up
which was just barely good enough for 64K RAMs, so everybody switched
to using that and put their steppers to work on more advanced projects.

Most companies also did redesign the memory cell, shooting down another
assumption in the paper.
-- 
A bit of tolerance is worth a  |     Henry Spencer at U of Toronto Zoology
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