The first idea that comes to mind is to fix it to a carrier Si wafer,
rather than a frame that only supports the outside. I'd probably use
photoresist, or maybe glue or epoxy; something that you can easily strip
off later. Then you'll have a friendly substrate on which to process the
foil.

Good luck,
Joe Grogan

Pavan Samudrala wrote:
> Hello all,
>
> I was wondering if anyone had experience doing lithography on foils. I am
> trying to pattern 3um features on a foil using MA8 and cannot get the foil
> flat to the surface of photomask. I tried bonding the borders of the foil to
> rectangular frame but still had some wrinkles (folds) which makes it
> difficult to pattern. The backside of the foil is also important and cannot
> destroy it. Any ideas would be appreciated.
>
> Thanks,
>
> Pavan Samudrala