[labnetwork] Upstream vs. Downstream Pressure Control

[Kevin McPeak]

Dear labnetwork users,

I posted a few days ago asking for advice on a thermal evaporator
purchase. Thanks to all those that responded, I really appreciate you
input.

We are also purchasing a RF/DC magnetron sputtering system for the lab
to deposit oxide and metal thin films. The leading contenders for this
purchase are the Lesker PVD 75 and the Nexdep from Angstrom
Engineering. Both seem like good options but one of the big
differences is the PVD 75 comes with upstream pressure control while
the Nexdep uses downstream pressure control. I have read that
downstream pressure control is the preferred method but that most
systems have upstream control. Lesker can do downstream control but it
cost more (and the PVD 75 is already more expensive than the Nexdep).
We aren't planning on doing reactive sputtering (Ar gas only) so I am
not sure how much this matters for us.

If anyone on the list has opinions good or bad about either of these
systems or the pros/cons of downstream/upstream pressure control I
welcome your insight.

Regards,
Kevin

-- 
Kevin McPeak Ph.D.
Postdoctoral Fellow
ETH Zürich
Optical Materials Engineering Laboratory
Universitaetsstrasse 6, CNB F121
CH-8092 Zurich, Switzerland
Voice: +41 44 632 6594
Email: kmcpeak at ethz.ch