I would say hands off the melt. If it can't be stored in the tool itself
under vacuum than store it in a clean dry place. Handle gently. If it is
a plastic box, make sure it doesn't outgas.

Immersing it in IPA I think is fairly scary. It would allow
contamination from the container to reach the target. The IPA would have
to be electronic grade at least. Any crevice defect would hold IPA. If
you dry with N2 the N2 could contaminate. When drying a liquid the
contamination concentration always reaches 100%, so you would have a
film on your target. I never heard of storing a target in a fluid. Of
course I haven't heard of everything.

Fabwipes can leave fibers even though they are clean wipes. The cloth
can tear on edges.

I think the better approach would to have a preparation procedure for
when the target goes back in. So much deposition on some dummy wafers.
The surface is ebeamed off, and the target heated and degassed.

I used to run wet decks and cleans. One thing you learn is never clean
silicon wafers from the vendor. They are always cleaner than any process
you can run in the fab, and anything you do makes them dirtier.

Sometimes your clean isn't as clean as the object itself.

My gut feel is that you should leave the target wrapped in clean wipes
in a dry place.

Though I would be interested in the reasoning behind IPA immersion. It
could be my thoughts are obsolete.

Ed

-----Original Message-----
From: mems-talk-bounces@memsnet.org
[mailto:mems-talk-bounces@memsnet.org] On Behalf Of Shivalik Bakshi
Sent: Tuesday, November 27, 2007 4:57 PM
To: General MEMS discussion
Subject: [mems-talk] Gold melt cleaning/storage protocol?

Hello all,

What is correct protocol for cleaning a gold melt (for ebeam) when not
in use?

Some of the suggestions that I have heard are:
(a) Immerse the melt in IPA when not in use
(b) No need to immerse it, but clean it using a fabwipe & IPA before use
(c) Hands off the melt. No need to clean it.


All comments & suggestions are welcome.