[mems-talk] Piranha etch

[Matteo Dainese]

Hello,
I need to use piranha solution (H2SO4 + H2O2)
to clean my wafers after etching, but it's not clear to
me what is the best ratio in solution between these two
chemicals to have optimal removal of resist and post etch
fluoropolymers.
In the literature I found H2SO4:H2O2 as 2:1 or 3:1 or even 6:1.
Sometimes there is water dilution. On the other hand they
never explain why they choose these ratios...
Has anybody of you some knowledge about this?
Thanks for the attention
Best Regards

Matteo