Hello Andrea

I do not think there is any resist that can withstand 200 minutes in HNA. Even a
very diluted one that I use doesn't hold the resist for more than 10 minutes.
You will have to use a hard mask. I have tried both positive and negative PRs
like 4620, KMPR 1010, they do not work.
It will be interesting to see if there is a resist that can hold for such a long
etch.

Deepa

Andrea Mazzolari  wrote: Hi all,
i'm looking for a photoresist which will be resistant to HNA etch. My HNA
composition is HF: 2 parts, HNO3: 15 parts, CH3COOH: 5 parts. Etch time is
200 minutes. So this photoresist must be resistant for a long time. Can
someone suggest a photoresist ? I have already tried S1813, but after
about 3 minutes etch it peeled off.