Hi,

 Recently someone mistakenly etched my wafer coated with aluminum through oxygen
plasma etching.

 I probed the wires and found none of them are electrical conductive anymore.

 Maybe the top layer of the aluminum has been oxidized.

 Is there any way to safely eliminate this layer of alumina without harm the
under layers that contain gold silver and SiO2?

 Will the phosphoric acid (H3PO4) do the job?

 Thanks!

 Hao