Hi,

I'm looking for a wet etchant that will etch 1000A Ta with PMMA as the mask.
PMMA seems to stand well in dilute acid and TMAH at low temperature. I've
tried 1:1 HNO3/HF which is too aggressive and reaction violently with the
silicon surface. Trancene has a Ta etchant that claims to work with PR and
contains HF and works at room temperture. Does anyone have more information
of such an etchant (composition, etch rate etc)?

Thanks,

--
Junjun Wu
Twin Creeks Technologies
Phone: 408-759-1426
Fax: 408-986-9142