In my previous laboatry, we use 1:1 H2SO4:H2O2 to do the standard clean every
time if we need to put the wafers into the furnace or some chambers. and put
your wafers into the sulotion for 15 minutes. The wafers should be clean.

Matteo Dainese  wrote:  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?