Sputtering of Cr film

[lsudh...@googlemail.com]

Hi,
I am having issues with magnetron sputtering of Cr. The chamber and
the film seems to have coloration after depositing the film at 3 mTorr
and a DC power of 50-100 W. Since the Cr film should look like a nomal
metal (no color), I am looking to find solution to this issue. Also,
can anybody help me in understanding the drift in the manometer
pressure reading when the plasma is turned on for deposition?
I would appreciate any input.
thanks.

[Kitty]

<lsudh...@googlemail.com> wrote in message
news:77165ea7-e690-448f...@25g2000hsx.googlegroups.com...

I would check the purity of your sputtering gas as well as the base
pressure. If you have access to an RGA, use that prior to sputtering and
just after.

Kitty

[Mark Thorson]

What purge gas are you using before pulling a vacuum?

[lsudh...@googlemail.com]

On Jul 31, 10:55 pm, Mark Thorson <nos...@sonic.net> wrote:

Thanks for your reply.
I ramp the temperature down to 50 oC before venting the vacuum with
nitrogen.

[lsudh...@googlemail.com]

On Jul 31, 6:47 pm, "Kitty" <cowgi...@bellsouth.net> wrote:
> <lsudheen...@googlemail.com> wrote in message

The base pressure is ~ 0.5 microTorr. I need to check the purity of
the gas. However, this coloration occurs only when I try and deposit
at high temperature ( 650 oC). Thanks.

[Kitty]

<lsudh...@googlemail.com> wrote in message
news:7544c8a1-cede-469f...@d45g2000hsc.googlegroups.com...

What gas are you using for the actual plasma? Nitrogen in the sputtering
chamber will cause a reactive sputtered film. I assume you are using Ar as
the sputtering gas? I personally would not vent a sputtering chamber with
N, if you must vent it, why not use Ar ? Do you vent the chamber because you
do not have any type of "prechamber" like a Loadlock? At what mTorr are you
sputtering? When sputtering Cr, Al etc, I like to have the presput pressure
at least 10-7 x 6 or lower. Also, what is the substrate material and what
has been the preclean process prior to sputtering the film?

Kitty

[lsudh...@googlemail.com]

On Aug 1, 10:29 am, "Kitty" <cowgi...@bellsouth.net> wrote:
> <lsudheen...@googlemail.com> wrote in message

I am using Ar for sputtering. The sputtering pressure is between 3-5
mTorr. Yes, I dont have have loadlock, hence, I the need for venting
the chamber. I have used Si and MgO as substrates. The cleaning
process involved Sonication in Acetone, immediately followed by
rinsing in Iso propanol and DI water (DI water only in the case of
Si). After which they were immediately dried under the burst of ultra
high pure Nitrogen. The base pressure is in mid 10-7 Torr. I shall try
and vent the system in Ar next time around. Thanks.
sudhee

[Kitty]

<lsudh...@googlemail.com> wrote in message
news:9578fefc-f252-4f3b...@y38g2000hsy.googlegroups.com...

Hmm, well I am thinking that all substrates must have significant rinse in
DI water, otherwise residue you cant even see, will adversely affect the
film purity. If you have sputter etch capability that would be helpful for a
preclean of the substrates or baking at high temp for a few hours {500-800C]
Also, are you sure the deposit temperature is 650C ? This is extremely high
for sputtering parameters. It might help to get the sputtering temp into the
200-300C range also. I have had to work with systems without the Loadlock
advantage { and with !} and found that I had to purge the sputtering
chamber{Ar} multiple times with pumpdowns in-between........just a thought.
Try purging with Ar 3x and then pumpdown 3x.....just my 2 cents..........
Keep us posted on your development & progress!

Kitty

[lsudh...@googlemail.com]

Thanks a lot; Will post the developments.