Hi,

If I 100% understood your problem, I think it's because of the resin
which did not resist at the edges of your exposed area ( under-etching)
more than gold is a hydrophilic material.

Instead, you can use the lift-off method to etch the metal.

have a nice day,

Alaa


Prasanna Srinivasan a écrit :
> Hello everybody,
>
> I need some inputs on gold etching. I have an SOI wafer with evaporated
> Cr/Au (40nm/500nm). The wafer was patterned using AZ9260 (6 micron thick).
> When I etched the exposed gold layer using pottassium iodide etchant (KI3)
> for about 55 seconds, I noticed large exposed areas (circles of 250 microns
> radius) are etched slower than the small narrow crevices (2-10 microns
> width) on a wafer. I was expecting exactly opposite behavior in the etch lag
> because, it should take a relatively more time for the etchant to reach the
> narrow crevices. Can anyone explain me why I notice this behavior? Also I
> would appreciate if anyone can suggest a suitable way to minimise the etch
> lag between different features.
>
> Thanks,
> Prasanna

--
Alaa el dine ALLOUCH
Doctorant au LAAS-CNRS-Groupe N2IS
7 Av colonel Roche, 31077 Toulouse
Tél : 05 61 33 78 71