Florian,  I believe that Piranha is useful because it is a very powerful
oxidant. Ti dioxide is already oxidized, so I would guess that absolutely
nothing will happen to the TiO2. I never tried it. But that would be my guess.

 Gary

---- General MEMS discussion  wrote:
>
> Hi
>
> I am looking for a process to remove Polyimide residues but not TiO2.  I
> can remove most of the polyimide with a Microstrip 2001 solution but
> there a still residues left. We know that a piranha clean would remove
> these residues but we are uncertain if it also attacks the titanium dioxide
> Does anyone have an idea how we can remove the polyimide without
> damaging the (13-nm) TiO2 layer?
> We also want to avoid the use of an O2-Plasma because that would damage
> our transistors.