Hello all,

I'm trying to etch gold through micro-hole features in a copper layer
(holes produced by a photoresist/lithography process).  I've tried aqua
regia vapor (maybe if I heat it up... but I don't want to hurt the
copper anymore than I have to) and I've tried potassium iodide, iodine,
water solution in a liquid state.

I've had success as long as the holes in the copper are large enough but
I need to access the gold in much smaller holes.  It seems like the
holes in the copper are too small for anything to gain access to the
gold.

Please assist me with this problem.

Best Regards,

Dave Lewis
Lake Shore Cryotronics
Ohio
[email protected]