Hi,

you can also try a double or triple coating with higher spinner speed on the
first turns and with a short softbakestep (~3 min) inbetween.
If the channels are very small and because of the resist viscosity some air
bubbles can be covered in the bottom of the channel. If this is the case you
can dilute the resist with PGMEA for the first coating turn.
This should reduce the maximum resist thickness (2005m) you have to back in
one time and therefore it should reduce the bubbles produced by evaporating
of the resist solvent.


Best regards

Bernhard Wieder

EV Group Inc. -  Technology Manager  -  Phone: 602 437 9492,  FAX: 602 437
9435,  e-Mail: [email protected],  Internet: www.EVGroup.com





Message: 1
Date: Wed, 15 May 2002 13:06:50 -0700 (PDT)
From: hongyuyu 
To: 
Subject: [mems-talk] Help on thick photoresist
Reply-To: [email protected]

Hi, friends

In bulk microfabrication, I tried to fill a deep channel, which is around
200um. When I use AZ5214, there are lots of air bubbles coming out when I
bake it. So how can I solve this problem?
Do I need to use different PR? High thick PR?
I want to try SU-8, but my friends told me that is a dirty material and
not easy to remove after baking.
Thanks a lot
Hongyu