I have alumina deposited on SiO2 substrate. How to pattern the alumina layer? I was thinking RIE with SF6 and CHF3, but this will etch into my substrate. Is there another method besides liftoff? Perhaps wet-etching?
Just a question for you, please correct me if I am wrong. Does the wet etch for aluminium and alumina are same? I thought they might be different but Sorry for my limited knowledge as I have not wet etched alumina myself.
Do you have BCl3/Cl2, you can use these gaseous to etch Alumina, but I am afraid that your selectivity might be poor. I do not know what are you using as a mask but a hard mask (Ni) is suitable for this purpose.
. Aluminum will oxidize as soon as it is in contact with the outside environment so I imagine that the Al etchant will have to etch the native oxide first, which is just a few nanometers. Based on Thomas I could simply use the Al etchant to etch alumina as well?