Cassie,

What's the substrate and surface films you have underneath the BCB?

Did the BCB change color after the curing process?  There're many
different thermal procedures for the polymer.  What's the EXACT
application baking/curing procedure you used?  (spin rate, softbake,
exposure/development?, stop points, ramping rates, end point, cooling
rate, etc.)

Trent

Cassie Iany wrote:
> Hello,
>
> I am using BCB (dow chemical) 4024-26, after curing in N2 oven, the surface
has very large bubbles which makes the surface looks ugly. Has anybody
encoutered the same problem? Any solution for it?