Rob,

I developed a good process for dry release of Aluminum structures with a
polyimide sacrificial layer. The release is CF4/O2 plasma (20/80 by flow, about
1 torr in an asher). This worked very well.

I've also done a wet release of aluminum using oxide as the sacrificial layer.
this worked, but we protected the alumimum in polyimide. This was a special
application and might not work in general.

Thanks,

Rob MacDonald
Shearwater Scientific


Robert Fahey writes:

Hi All

I would like to release etched metal (probably titanium or aluminium) shapes
such as cantilevers or beams from an underlying sacrificial layer. The sacficial
layer would probably be oxide or nitride. However I am having difficulty finding
an etchant that would remove the oxide or nitride while not attacking the metal.
Can anyone please suggest any?

Alternatively can anyone suggest a different sacrificial layer - is it possible
to deposit metal onto a sacrificial polymer layer- how would I then remove the
polymer?

And finally! - does anyone here have any experience etching of stainless steel-
can you please tell me what etchant you used and any points of interest?

thanks very much
Rob