(Assuming you are going for a custom made = head ache + money)
Define your needs.
Some tips:
We went for a split box (two boxes) with separate atmosphere. One box is
organic and the other can be used by just anyone (inc. III-V people).
In the "organic" box we have solvent adsorber on top of the O2
and H2O adsorber. Note - not all solvents are compatible with
the adsorbers (ask for a list).
If it is important to you that you'll never have water/oxygen levels above10-20ppm
then you should ask for a second adsorber system to operate while you regenerate
the first one. During normal operation there shouldn't be a problem to
keep below 1ppm (in ours it is below 0.1ppm - detector limit).
In the organic box we have a vacuum oven for annealing. It is best to have
an oil-free pump for it (otherwise you might have a bit of oil on the surface
and very interesting contact phenomena). Ask for a programmable oven and
make sure you can specify also the cooling rate (don't take it for granted).
In the organic box we have a programmable spinner. It is recessed into
the box floor (has its own small box) and there is special suction that
opens to the spinner box when it is operated. This way the solvents that
evaporate during the spinning do not contaminate the entire box. Ask also
for a foot switch.
Make sure to have electrical feedthrough to the box in the form of BNC
and possibly TRIAX too. Also add some standard vacuum type connections
of the KF or NW type.
Anti-static gun to reduce static electrical charge.
If your box and load-lock chambers (ante-chambers) are connected to the
same pump ask for one way valve so that you won't fill chamber A when you
start pumping chamber B (or reduce pressure in the glove box).
A refrigerator or a cold well (5c) might be a god idea.
If you intend to keep clean environment - Heppa filters. In any case keeping
the box clean is hard.
If you intend to collaborate with clean room people you should know that
they are very sensitive to Copper tubing (traps in Si). You can ask for
stainless in the box tubing and should have inert gas pipes made of stainless
(note the different grades + price).
In our general box we have a metal evaporator. If you intend to deposit
also dielectrics and organics you should remember to perform special cleaning
procedures to avoid cross contamination. You may be tempted to think that
water are not going to be an issue - wrong (ppm is a lot at 10-7mbar).
We have a 306 (edwards) with cryo pump and a dry rotary pump (goes down
to 3x10-7 in 30 minutes). The advantage of a cryo is that it
runs all the time so that your vacuum chamber is all the time clean (pumps
fast). Drawback - noise and vibrations (ask for a solution).
DO NOT FORGET - make sure to get a precise definition of the system requirements
in terms of: Inert gas flow (l/min), cooling water (l/min + in-out pressure
difference), electrical power. Don't forget that for your custom made system
you are not supposed to get the "standard" brochure.
Start with a survey of relevant companies and try to find a combination
of a good company with a reliable local representation. If your local agent
has no technical knowledge than you should expect the number of "misunderstandings"
and "mistakes" to shoot up to the sky (If you are lucky you'll catch them
all in time).
We bought ours from M
Braun and we got more then we asked for.