PVD Vaccum Chamber -- How to clean up after Water leakage?

[lamejane]

TL;DR

Solution to get rid of water in a vacuum chamber

Hello all ,

our PVD chamber experienced a water leakage from the cruible revoler area and unfortunately we are no longer able to achieve a stable Base pressure ( ~10e-6 mbar)

We do not have the option of a bake out. Is there any other way to get rid of water in the chamber ?
Ofcourse the water has been wiped out dry using clean room wipes, but i suspect there is still some monolayers of water adhering strongly to the chamber surface. Would repeated Nitrogen flusing help in getting rid of the water molecules? ?

Thanks !
Rgds
Jane

 

[.Scott]

Applying a vacuum will chill the water - potentially causing it to freeze. But maintaining the vacuum long enough for any traces of water to remelt and evaporate should not be difficult. Likely just a few minutes.

Is it possible that something else happened during the clean-up that is compromising the seals?

 

[bobob]

Yes, repeated dry nitrogen flushing and pump down should do it. Removing screws and other things where water could be trapped will also help a lot. I see lots of nooks and crannies where there could be water trapped. I don't think you have to worry at all about the surfaces you have wiped down. What kind of pressure are you able to achieve? If you are getting to a few mtorr, you might look for a leak. Usually, water in screw threads and other nooks and crannies will manifest itself as a sort of "popping" on the vacuum gauge.

 

[Dullard]

If you can heat the Nitrogen, things will go even quicker. If you have a 'nooks and crannies' problem, Acetone can help to get the water out in the open.

 

[lamejane]

Is it possible that something else happened during the clean-up that is compromising the seals?

the root cause is unkown but we suspect that the seals were faulty.

 

[lamejane]

Yes, repeated dry nitrogen flushing and pump down should do it. Removing screws and other things where water could be trapped will also help a lot. I see lots of nooks and crannies where there could be water trapped. I don't think you have to worry at all about the surfaces you have wiped down. What kind of pressure are you able to achieve? If you are getting to a few mtorr, you might look for a leak. Usually, water in screw threads and other nooks and crannies will manifest itself as a sort of "popping" on the vacuum gauge.

Thank you, This suggestion along with heating the chamber walls with a hot blowdryer (industry grade) prior to chamber evacuation helped.
We have no Leaks.