Once Chromium touches air it will oxidize.  You may be seeing the natural
oxide coating of chrome once it is removed from the vacuum chamber.

Gary Hillman
S-Cubed
PO Box 365
9 Mars Ct.
Montville, NJ 07039
phone 973-263-0640 ex 35
fax 973-263-8888


-----Original Message-----
From: mems-talk-bounces+garyh=s-cubed.com@memsnet.org
[mailto:mems-talk-bounces+garyh=s-cubed.com@memsnet.org]On Behalf Of
Ruiz, Marcos Daniel (SENCOE)
Sent: Wednesday, January 26, 2011 2:12 PM
To: General MEMS discussion
Subject: Re: [mems-talk] RF-DC sputtering _ need some suggestion(s)


Is it possible our oxygen is coming from the chamber?

Is the system load-locked?

A load-lock will prevent air and moisture from entering the deposition
chamber, so clearly that would be preferable.

What base pressure are you pumping to before the start of deposition?
How long are the samples held at base pressure before the start of
deposition?

Pumping to and holding at a low base pressure works to remove air and
moisture introduced during loading.  Lower base pressure and longer pump
times are preferable.

Dan Ruiz