Jiang,

I agree with Chad try using a separate container and when pouring try to get as
close as possible to your substrate and pour very slowly. If the su-8 isn't to
thick you can try and use a pipette to dispense the su-8 onto your substrate.

-----Original Message-----
From: Brubaker Chad 
Subject: RE: [mems-talk] su-8 air bubble problem

Jiang,

The issue may be that the bubbles are in the su-8 prior to dispense on
the wafer.  The high viscosity of the thicker formulations can be so
great that bubbles will not float out of the solution, (especially
smaller bubbles), and may deposit onto the substrate.

One way to eliminate these bubbles is to placed a sealed container of
the SU-8 (sealed so it doesn't dry out) into an oven a moderate
temperature (60 - 80 C).  This will reduce the viscosity of the
material, allowing the bubbles to rise out.

Best Regards,
Chad Brubaker