[labnetwork] NiFe 81-19 Sputtering Request

[J Romans]

Hi Michael -
Are you sure your gun is correctly setup to sputter magnetic materials?
This usually requires removing or changing the polarity of a permanent
magnet(s). With our PVD 75 at the University of Illinois, we only RF
sputtered oxides so I never had to worry about this there and couldn't tell
you exactly what needs to be done.

Also, I've found the Lesker shield (outer, ground electrode) to be very
flimsy and susceptible to distortion due to heating - especially the ring
on top that sets the gap between the outer electrode and the target hold
down ring. I would purchase some of these to have on hand anyway.

Also check to make sure everything is very clean. One critical point is the
top ring mentioned above. The other being where the outer electrode
attaches to the gun at the bottom. These screws not only set the gap
between the two electrodes but complete the ground path.

Also make sure there are no high spots on the pan head screws that hold
down the target. The flat tip screwdriver slot is easy to get buggered up.
Buy some spares of these also.

Also make sure there are no high spots on your target (from arcing, etc.).

Finally, I would sometimes have to "cheat" to increase the gap between the
two electrodes. When installing the outer electrode, don't allow the slot
in the can to fully fall onto the attachment screw. Just make sure this is
done evenly on all slots so the gap between the electrodes is uniform. You
may want to try this early in your troubleshooting to confirm the problem
is a spacing issue between electrodes. If it is the problem, you may decide
to complete your urgent deposition before fixing the underlying problem.

Good luck,

J. Hal Romans
Senior Equipment Engineer
University of California San Diego
hromans at ucsd.edu


On Sun, Jun 19, 2016 at 10:03 AM, Matt Moneck <mmoneck at andrew.cmu.edu>
wrote:

> Hi Michael,
>
>
>
> It was great meeting you at UGIM.  We’ve had our fair share of issues
> sputtering NiFe in the past.  With NiFe being such a high permeability
> material, the issues we typically see revolve around low pass through flux
> (i.e. too much shunting of magnetic field through the target) as a result
> of the NiFe target being too thick and/or cathode magnets being too weak
> (we typically use NdFeB).  We have even gone as far as to cut an erosion
> groove in one of our NiFe targets (it was too thick when ordered) to
> increase the pass through flux enough to trap electrons at the target.
> However, in the above scenarios, we would have a situation where the plasma
> would only ignite at high pressure or not ignite at all.  In those cases,
> we either need to run RF (typically results in high reflected power) or
> make a change to the target and/or cathode.
>
>
>
> Your case is obviously a bit different as it seems that you can run the
> plasma for a few runs before it fails.  We have seen similar failure
> mechanisms, but they can be caused by many factors.  Are your burn-in runs
> done at a different pressure and DC power than the 800 W runs that are
> failing?  Also, are the failed runs always right after a conditioning run
> or burn-in run?  Furthermore, have you had a chance to inspect the target
> and shields for buildup of material (we have seen intermittent shorts that
> only occur after sputtering for some time)? More recently, we even had a
> magnetic target (CoFeB) crack and subsequently display the type of behavior
> you are seeing.
>
>
>
> If you need a run for your client, we are set up to do NiFe and can handle
> wafers up to 6” diameter.  We would only need to know what type of
> substrate as well as the requirements for film properties (thickness,
> stress, coercivity, need for easy axis, etc.).  My only concern is that it
> may take several days to get a contract in place.  I will forward the
> agreement to you in a separate email if you are interested in pursuing this
> further.
>
>
>
> Best Regards,
>
>
>
> Matt
>
>
>
> --
> *Matthew T. Moneck, Ph.D.*
> Executive Manager, Carnegie Mellon Nanofabrication Facility
> Electrical and Computer Engineering | Carnegie Mellon University
> 5000 Forbes Ave., Pittsburgh, PA 15213-3890
> T: 412.268.5430
> F: 412.268.3497
> www.ece.cmu.edu
> nanofab.ece.cmu.edu
>
>
>
> *From:* labnetwork-bounces at mtl.mit.edu [mailto:
> labnetwork-bounces at mtl.mit.edu] *On Behalf Of *Michael Khbeis
> *Sent:* Sunday, June 19, 2016 12:40 AM
> *To:* labnetwork at mtl.mit.edu
> *Subject:* [labnetwork] NiFe 81-19 Sputtering Request
>
>
>
> Dear Colleagues
>
>
>
> We have an issue sputtering NiFe in our Lesker PVD75. The target runs fine
> for burn-in and a few runs but then can't maintain a plasma (DC 800W).
>
>
>
> Does anyone have an idea what causes relatively rapid failure in
> maintaining plasma with this specific material? I doubt the target is worn
> that fast.
>
>
>
> Also, we have a client that urgently needs some depositions. Is there a
> site willing to take on the task while we troubleshoot our system?
>
>
>
> Gratefully,
>
> Dr. Michael Khbeis
>
> Washington Nanofab Facility
> University of Washington
> Fluke Hall, Box 352143
> (O) 206.543.5101
> (C) 443.254.5192
> khbeis at uw.edu
>
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>
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