Dear all
    I am looking for pinhole free metallization. I am using KOH etching
to release my device. But the eletric contact under the metal pads will
be etched. I guess the reason is the pinholes in the metallization. I
tried Cr 30nm/ Au 300nm, Cr 40nm/ Pt 200nm/ Au 200nm and other kinds of
multilayer metallizations with both ebeam and thermal evaporatoration.
But none of them give me desired results. Since Au is used, even 200nm
Pt layer can not prevent it diffusing into Si with annealing at 400C for
5min (by RTA). Do you have some advices on pinhole free metallization
without gold? Thanks in advance.

Best
Hongtao