Well, let¡¯s generate some traffic!
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About 25 years ago I worked at a small thin
film R&D
outfit in Ventura CA. It was the most fun job I¡¯ve had. Part of it
was
maintaining the sputtering system that was central to the whole
operation. It
had a 5HP mechanical roughing pump followed by a small turbo.
Turbo was
connected to the load lock chamber. The sputtering chamber itself
was pumped by
a cryo. It was a two target Gartek sputtering system. A shuttle
system,
magnetically coupled to an external drive, moved a pallet holding
the wafer to
be coated from the load lock to the first position - a
water-cooled table that
raised up to hold the pallet. Bellows allowed the motion in the
vacuum. Once
the cryo took the chamber down to 10^-6 Torr (ion & pirani
gauges) the
chamber was flooded with a small amount of Argon. A magnetron
target above the
wafer was then energized with either 13.56 MHz RF if it was a
dielectric target
or DC HV for conductive target. The resulting plasma sputtered the
atoms from
the target to the wafer. When that was done the wafer on the
pallet could be
moved farther into the system to the next table and target for the
next
material coating. We sputtered Gold, Palladium, Titanium,
Titanium-Tungsten,
Copper, and some dielectrics that I don¡¯t recall. I wrote the
software that ran
the system in Forth (the boss liked Forth) rebuilt each pump,
designed the load
lock door and target magnets, and so on. Thus began my love of
vacuum science.
Now I have a small diffusion pumped system in my home shop, just
for fun.
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The gurgle of a roughing pump, the whine of an
accelerating
turbo, the throbbing of a cryo cold head drive. Music to my ears.
Steve WA6EJO
