Hey there Zoltan.  I think that a quick 02 ash would be very beneficial
to help remove the splotches.  You may also need to work with your
develop time a little.

Good luck!

Best Regards,
Dustin Warren, PE

EV Group
invent * innovate * implement
Application Engineer - Direct: +1 (480) 305 2447, Main: +1 (480) 305
2400 Fax: +1 (480) 305 2401
Cell: +1 (480) 274 3894
E-Mail: [email protected], Web: www.EVGroup.com


-----Original Message-----
From: walter [mailto:[email protected]]
Sent: Sunday, April 12, 2009 6:58 PM
To: General MEMS discussion
Subject: [mems-talk] PR adhesion to gold

Greetings all.

We are running into difficulties with the adhesion of 1813 PR to gold.
We never experienced this problem before.

In the past we used AP 100 series from Silicon resources however they no
longer seem to be in business.

We now use recommended omnicoat sold through micro chem,
I t works well.

The problem is once we develop /etch the PR, blotches of the omnicoat
remain.
We cure the omnicoat at 200 degrees C.

70 percent of the wafer looks perfect the rest we cannot remove the
omnicoat.
Questing what chemical can we use to remove the Omnicoat without
affecting the remaining PR pattern.

I am sure that someone has the answers out there in cyberspace.

Thanking you in advance

Zoltan