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


-----Original Message-----
From: mems-talk-bounces+dan.ruiz=honeywell.com@memsnet.org
[mailto:mems-talk-bounces+dan.ruiz=honeywell.com@memsnet.org] On Behalf
Of Yassine AEA
Sent: Wednesday, January 26, 2011 10:57 AM
To: mems-talk@memsnet.org
Subject: [mems-talk] RF-DC sputtering _ need some suggestion(s)

Cr-doped IO samples have been grown in-house on p-Si(100) by using
RF-DC sputtering deposition method. The RF is used for IO target
(125-250w) and DC for Cr-target ( 7-15W). The argon flow is kept at
24 mTorr.

Recently, SEM-analysis shows the samples are oxygen rich (80 %), we
have been advised to buy a new target and to use a heater to keep the
substrate at certain temperature in one side and in the other side to
descend the percentage of oxygen. Yet, we are still getting a very
high atomic percentage of oxygen.

Any suggestion, idea will be great.

thanks,
Yassine,Ait El Aoud
UML,MA