Dear All,

  I have a structure off Au/Cr with plated Copper on top. I am trying to find a
way etcing the Au/Cr (seed layer). I can either etch the Au/Cr after Cu plated
or use lift-off process. However, I am concerned with etching Au/Cr after Cu
plated without affect Cu. If I put resist first before seed layer of Au/Cr, Then
pattern it again for Cu plating, I am not sure if I can lift off the seed layer.
Can anyone give some ideas for either situations? What are the etchant(s) that
is/are better for the processes? Thanks.

  Terry Zhu