Thanks for the clear replies to my questions.  Based on your answers, it
is safe to say that you are doing a good job of eliminating oxygen and
moisture from the chamber before deposition.

The only other source of oxygen is your "IO" sputter target.  Although I
have no experience sputtering this alloy, I suspect that the oxygen in
the "IO" target is sputtered at a greater rate (maybe 4X faster) than
the other element.  Thus, the resulting film on your samples is oxygen
rich.

This supports the advice you've already received about getting a new
target.  I think the other piece of advice you got about wafer
temperature probably serves to keep free oxygen out of the solid phase.

Your sputter target vendor would probably be a good resource here.  They
may be able to tell you what target you need to buy (percent oxygen) to
achieve the oxygen level you require in your samples.

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 11:55 AM
To: General MEMS discussion
Subject: Re: [mems-talk] RF-DC sputtering _ need some suggestion(s)

Hi Dan- thanks for your reaction.

 Is it possible our oxygen is coming from the chamber?------- I probably
do
not get the point , but we clean the chamber everytime when it  un/load
the
sample.

Is the system load-locked?-------Yes

What base pressure are you pumping to before the start of
deposition?--------5E-7

How long are the samples held at base pressure before the start of
deposition?----------- I do not know excatly, but we leave the sytem
pumping
down overnight and in the morning we start  grow the film.

I am unsure if I am saying it right but I am wondering if there is any
restriction for substrate-target distance, also I have read that the
substrate has to be baked and cleaned firstly for a certain time before
the
deposition.

what do you think?

Many thanks,

Yassine,Ait El Aoud