Buying a Glovebox System
(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 glovebox).
- 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.