Hi

We have a problem regarding the removal of resist.

We have two wafers with memsstructure of aliminum and gold
respectively. We want to release them by etching a sacrificial crome
layer. On top of the crome a protective layer of Shipley's S1813
resist was put to protect the wafers durings transport.

The resist was only softbaked after spinning.

What obviously happened was that the wafers were stored for too long
(around six moths) and now the resist can't be stripped by acetone,
which is what we normally use.

Can anyone here think of any other way to remove the resist? It might
be possible to etch itm but most ethcants etch metals faster than
resists, which would be a big problem.

/Sven Holmström, Koc University, Istanbul