I have had this problem in the past. You should hard bake the 1st
photoresist layer after developing.

  2 minutes at 140 C in a hot plate worked for me.



El 28/04/2011 17:12, basar bolukbas escribió:
> Dear All,
>
> I want to make a air bridge fabrication, but i have some problems.
>
> When i spin-coat second resist layer on top of first one, my first layer is
dissolving due to second resist's resolvent i guess.  I couldn't solve this
problem even i tried different a lot of things.  So i couldn't make double photo
lithography.
>
> Could you suggest some details to me?