The outgasing and shrinkage issue of the PR during the metal coating
could induce the problem. You can try hard-bake the PR a little after
the lithography and before the evaporation. Say 2mins @ 120 C.

2011/11/20 Yuksek, Nuh S. (MU-Student) :
> Hi,
>
> I use AZ4620 as a sacrificial layer and deposit a Cr/Au layer on top of
patterned 10-15 micron thick AZ4620 by RF sputtering. When I remove the samples
from the sputtering chamber I can clearly see that the metal film is cracked in
50-100 micron size pieces completely ant that affects the reflection from the
surface. Sometimes I see very rough wrinkles on the film.
>
> Has anyone faced this problem and how can I overcome this issue? What may
cause this crack or wrinkle issue?
>
> NSadi

--
Yunda Wang, Ph.D. Candidate
Department of Mechanical engineering
University of Colorado - Boulder
Boulder,Co. US. 80302
(614)3120920
E-mail: yundawang@gmail.com