Hello,

Is anyone aware of a wet or dry (RIE or Ga-ion milling) etching
process to pattern ~10nm high quality HfO2 made by ALD?

Below I have GaAs, but I have no problem if the etchant attacks/etches the
surface here also.

If possible, I want to avoid etchant agents which attack metals like
Pd,Au,Ge and Ni.

Diluted HF works not very well, due to very inhomogeneous etching. Same
holds for RIE using SF6+He.

Thank you in advance.
Daniel