Noemi,

 in our lab we normally start from PMMA 8% and we dilute that to 4%. After
spinning and curing the dilution, we obtain a final thickness of ~180 nm.
We have also diluted down to 2% without any trouble.
Let me know if you have any question.

 Fabio


On Thu, 13 Oct 2005, Noemi Graziana SPARTA' wrote:

> Dear all,
>
> I'm starting to work on PMMA 950K 9%.I'd like to reduce viscosity to
> operate with a thickness (after spin coating) in the range of
> 100-200nm.I'd like to know if the procedure of dilution in chloro
> benzene is a good solution or if it's raccomended to buy a new bottle
> with proper viscosity.
>
> Thanks in advance
> Noemi