Hi,

I want to make a selective etch of a 10µm thick TiO2 layer on Ti substrate
but I haven't managed to find any information. From the information
that I have found, TiO2 is etched very slowly when put in a SC1 cleaning
solution (NH4OH:H2O2:H2O; 1:1:5), but the Ti is also etched by this solution
(because of the simultaneous oxidation/deoxidation due to H2O2 and NH4OH).

I have tried to use only NH4OH (30%), to see if it work but in vain. Next I
have mixed NH4OH and H2O2 to be sure that the titanium was attacked
by this solution. The Ti was attacked quite fast but the oxide layer didn’t
react.

For information, the oxide layer is obtained by wet thermal oxidation of the
Titanium sample at 800°C.

Thank you for your help.

Anthony De Luca