Maybe you should remove the bubbles in PDMS before pouring onto the
wafer? I don't know much about the chemistry involved but perhaps the
chlorinated silane coating is somehow being affected by the air bubbles.
Just a thought.


Bo Bob Huo wrote:
> 7. Put ~1mL chlorinated silane (tridecafluoro 1,1,2,2 tetrahydro
> octyl)-1-trichlorosilane (Sigma, #448931) in a small glass vial and
> put in the vacuum chamber for at least 4hrs.
> 8. Pour the PDMS on the wafer and remove the air bubbles in vacuum
> jar for less than 1.5 hour.