On Thursday, November 6, 2003, at 09:56 PM, Riad S. Wahby wrote:
"Major Variola (ret)" <mv@cdc.gov> wrote:
At 08:22 PM 11/6/03 -0800, Tim May wrote:
I heard ten years ago that the National Semi fab on-site was a lowly 2-micron fab. Which was enough for keying material.
And rad-hard circuits for their buddies at the NRO.
Probably not on a CMOS process, though. For the most part, rad-hard==bipolar, even nowadays.
Most ULSI today is BiCMOS, but Intel, Harris, and a bunch of others were making rad-hard CMOS nearly 20 years ago. The 80C86 rad hard part was and is used in a lot of critical apps. True enough, a project I consulted on picked the AMD 2901 for the Galileo Jupiter mission, and it was bipolar. And of course the concern with shrinking geometries has moved from "suntan" effects (long exposure) to SEUs. And here the advantages mostly are with SOI (as they were with SOS and SOI when I started working on SEUs in 1977). --Tim May