Hi!

After several ebeam lithogarphy steps, where I have patterned
freestanding structures out of SOI, I want to remove
selectively some
parts of the upper Silicon layer. So I spin on resist (PMMA
500000, 7%),
bake it at 170°C for 2 minutes. After ebeam exposure, I
develop and use
a RIE ICP with SF6 and Ar (5:10) to etch away the unprotected
areas on
the Chip.
All this works fine, the only problem is, to remove the resist
afterwards. Aceton does not work properly, some parts of the
resist
remain. I can't apply an O2 Plasma, because there are magnetic
structures on the Chip. This is probably dur to the fact, that
etching
does harm to the PMMA layer.

Do you have an idea, how to get rid of the resist?

Thank you!
Stephan