evan,

the white residue occur mean that the development process not yet complete.
simply immerse additional developer to revome the white residue and continue
development.


On Thu, Nov 12, 2009 at 7:40 AM, Evan Lunt  wrote:

> I would like to partially develop a 5-10 um-thick Su-8 film on a Si wafer.
> After the partial development, I am going to deposit a thin metal layer and
> perform a liftoff by finishing the Su-8 development. So far, I have
> experienced two major problems with this:
>
> 1. Su-8 developer is removing the unexposed Su-8 too quickly. Is there any
> way to slow down the development (i.e. dilution)? I would like to avoid
> excessive baking of the wafer.
>
> 2. As is widely known, when partially-developed Su-8 is rinsed with
> isopropanol, a white residue results. Is there anything else to rinse the
> developer (besides water) that will stop the development and not create the
> white residue? Is there a different developer that I can use (i.e. ethyl
> lactate, diacetone alcohol) that I can rinse away with out creating the
> residue?
>
> Thank you,
> Evan