I think you mean GBL rather than PGMEA? I have doubts as to whether a
5-10nm layer is possible via spin-coating (I have never heard of anyone
trying this).
The following thread may be useful:
http://mail.mems-exchange.org/pipermail/mems-talk/2006-January/139480.html


stefano.park@gmail.com wrote:
> Hi guys
>
> I would like to make 5-10 nm thickness of  SU-8 solution so that I am
> going to dilluted with PGMEA.
>
> What do you think the ratio bewteen SU8-2002 and PGMEA for the 5-10nm
> thickness?