Dear friends

I have a peculiar problem of etching of Silicon using TMAH without at all
affecting the patterned Nickel on oxide.
Nickel ( thermally evoporated for thickness of 800A) is patterened with PR and
lithography on the SiO2/si, etching of  the exopsed Si using TMAH  ( 10%wt, 80C)
has to carried out. Now i would like to know that how the Nickel film will be
affected by this solution and what will be the characteristics of the the
etching. i tried the same with KOH  at room tempearture and there is negligible
etching of nickel for a long time.

any suggestions will be highly appreciated.

thank you