Re: Czy komuś padł procesor ze starości?

Procesory serwerowe IBM z serii Power są budowane w specjalnej
technologii z wyższymi strukturami co podwyższa ich niezawodność.

http://www.csee.umbc.edu/help/architecture/power4.pdf

Reliable All the Way Down to the Silicon

The CMOS-8S2SOI process was developed in IBM’s East
Fishkill process-development labs. This 1.5-V seven-layermetal
process is a variation of IBM’s 0.18-micron copper
CMOS-8S (see MPR 9/14/98, p. 1), which IBM will put into
production later this year. The 8S2 derivative has 15% shorter
channel lengths (Lg < 0.12 Îźm) and is built on a silicon-oninsulator
(SOI) wafer (see MPR 8/24/98, p. 8). According to
IBM, the low parasitic capacitance of SOI transistors boosts
logic speed by over 25% compared with an equivalent bulk
process, while also reducing power consumption.
A major constraint placed upon the development of
CMOS-8S2SOI was very high reliability. Most processor
manufacturers design their gate dielectrics to a Grade 3
failure-rate specification of 1,000 FITs (failures per billion
hours). IBM, however, says this isn’t good enough for duty in
continuous-availability servers, because internal errordetection
features extensive enough to compensate for ICprocess-
reliability problems would add cost and sacrifice
considerable speed. As a result, IBM specifies its processes to
a 10-FIT failure rate, two full orders of magnitude better
than most companies.

To meet this stringent specification, the 8S2 gate oxide
had to be made 3.6 nm thick (Tox at 1.5V), 20% thicker than
the gate oxide in Intel’s 0.18-micron 1.5-V P858 process
(see MPR 1/25/99, p. 22), which it will use for Merced and
McKinley. IBM had to develop other means to compensate
for the losses of transistor drive current and of switching
speed that result from the thicker gate oxide. SOI and copper
were key to achieving these goals. Copper also improved the
reliability of the on-chip interconnects; because the metal is
nearly impervious to electromigration, it can sustain higher
currents for longer periods without failing.
Received on Wed Sep 6 13:55:09 2006