Hi Sardar Bilal,

       Cu is the seed layer on wafer and whether Ni and Ag are in
contact with each other (and with Cu)...If the metal layers are in
contact with each other then it may lead to galvanic corrosion in
which one metal corrodes preferentially than the other type of metal
and both metals are in an electrolyte. if this is the case, then you
can try selective metal deposition instead of depositing on whole
wafer and etching later...

-Ravi Shankar