Hi, all

I have a sample with photoresist on which is put aside for quite a long time
(say half a year). The photoresist is "lift-off photoresist LOR-10B" and
"positive photoresist S1813".

After I sputtered ZrO2 on it, I can not lift them off by acetone or develop. It
looks like too strong. Does anyone here know why? Does long time storage cause
any problem?

How can I dissolve this? should I use stronger solvent?

thank you very much for your kindly suggestion.

Nice weekend

Xiaoyuan